47 results on '"Andrea Steck"'
Search Results
2. Nigroxanthin (3?,4?-Didehydro- ?,?-carotene-3,6?-diol), a New Carotenoid Isolated from Paprika (Capsicum annuum var. longum nigrum)
- Author
-
József Deli, Zoltán Matus, Péter Molnár, Gyula Tóth, Gábor Szalontai, Andrea Steck, and Hanspeter Pfander
- Subjects
Chemistry ,QD1-999 - Abstract
From red paprika (Capsicum annuum var. longum nigrum) nigroxanthin (1) was isolated as a minor carotenoid and, based on its spectral data, identified as (all-E)-3?,4?-didehydro-?,?-carotene-3,6?-diol.
- Published
- 1994
3. Islet autoantibody screening in at-risk adolescents to predict type 1 diabetes until young adulthood: a prospective cohort study
- Author
-
Mohamed Ghalwash, Vibha Anand, Olivia Lou, Frank Martin, Marian Rewers, Anette-G Ziegler, Jorma Toppari, William A Hagopian, Riitta Veijola, Peter Achenbach, Ezio Bonifacio, Claire Crouch, Jessica Dunne, Helena Elding Larsson, Brigitte I Frohnert, Jianying Hu, Heikki Hyöty, Jorma Ilonen, Josefin Jönsson, Michael Killian, Mikael Knip, Eileen Koski, Åke Lernmark, Ying Li, Zhiguo Li, Bin Liu, Markus Lundgren, Ashwani Malhotra, Marlena Maziarz, Jocelyn Meyer, Shelley Moore, Kenney Ng, Jill Norris, Shreya Roy, Lampros Spiliopoulos, Andrea Steck, Harry Stavropoulos, Kathleen Waugh, Christiane Winkler, and Liping Yu
- Subjects
Pediatrics, Perinatology and Child Health ,Developmental and Educational Psychology ,Article - Abstract
BACKGROUND: Screening for islet autoantibodies in children and adolescents identifies individuals who will later develop type 1 diabetes, allowing patient and family education to prevent diabetic ketoacidosis at onset and to enable consideration of preventive therapies. We aimed to assess whether islet autoantibody screening is effective for predicting type 1 diabetes in adolescents aged 10−18 years with an increased risk of developing type 1 diabetes. METHODS: Data were harmonised from prospective studies from Finland (the Diabetes Prediction and Prevention study), Germany (the BABYDIAB study), and the USA (Diabetes Autoimmunity Study in the Young and the Diabetes Evaluation in Washington study). Autoantibodies against insulin, glutamic acid decarboxylase, and insulinoma-associated protein 2 were measured at each follow-up visit. Children who were lost to follow-up or diagnosed with type 1 diabetes before 10 years of age were excluded. Inverse probability censoring weighting was used to include data from remaining participants. Sensitivity and the positive predictive value of these autoantibodies, tested at one or two ages, to predict type 1 diabetes by the age of 18 years were the main outcomes. FINDINGS: Of 20 303 children with an increased type 1 diabetes risk, 8682 were included for the analysis with inverse probability censoring weighting. 1890 were followed up to 18 years of age or developed type 1 diabetes between the ages of 10 years and 18 years, and their median follow-up was 18·3 years (IQR 14·5–20·3). 442 (23·4%) of 1890 adolescents were positive for at least one islet autoantibody, and 262 (13·9%) developed type 1 diabetes. Time from seroconversion to diabetes diagnosis increased by 0·64 years (95% CI 0·34–0·95) for each 1-year increment of diagnosis age (Pearson’s correlation coefficient 0·88, 95% CI 0·50–0·97, p=0·0020). The median interval between the last prediagnostic sample and diagnosis was 0·3 years (IQR 0·1–1·3) in the 227 participants who were autoantibody positive and 6·8 years (1·6–9·9) for the 35 who were autoantibody negative. Single screening at the age of 10 years was 90% (95% CI 86–95) sensitive, with a positive predictive value of 66% (60–72) for clinical diabetes. Screening at two ages (10 years and 14 years) increased sensitivity to 93% (95% CI 89–97) but lowered the positive predictive value to 55% (49–60). INTERPRETATION: Screening of adolescents at risk for type 1 diabetes only once at 10 years of age for islet autoantibodies was highly effective to detect type 1 diabetes by the age of 18 years, which in turn could enable prevention of diabetic ketoacidosis and participation in secondary prevention trials. FUNDING: JDRF International.
- Published
- 2023
- Full Text
- View/download PDF
4. Physical activity and progression to type 1 diabetes in children and youth with islet autoimmunity: The diabetes autoimmunity study in the young
- Author
-
Janet Snell‐Bergeon, Kathleen Waugh, Fran Dong, Andrea Steck, Jill Norris, and Marian Rewers
- Subjects
Islets of Langerhans ,Diabetes Mellitus, Type 1 ,Adolescent ,Endocrinology, Diabetes and Metabolism ,Pediatrics, Perinatology and Child Health ,Internal Medicine ,Humans ,Autoimmunity ,Prospective Studies ,Child ,Exercise ,Article ,Autoantibodies - Abstract
AIMS/HYPOTHESES: Physical inactivity may contribute to islet autoimmunity and progression to clinical type 1 diabetes. To test this hypothesis, we evaluated physical activity, assessed by accelerometer, as an independent risk factor for progression to clinical diabetes among genetically at risk for type 1 diabetes children and youth with islet autoimmunity. METHODS: Accelerometer data were obtained for 95 children and youth participating in the Diabetes Autoimmunity Study in the Young who had islet autoimmunity. Islet autoimmunity was defined as the presence of islet autoantibodies to insulin, glutamic acid decarboxylase, tyrosine phosphatase-like protein IA-2, or zinc transporter 8. RESULTS: During prospective follow-up for up to 7 years, 13 of the 95 participants progressed to clinical diabetes. In multivariable survival analysis, none of the physical activity parameters examined predicted a higher risk of developing diabetes. In survival analysis with time-varying physical activity parameters, none of the physical activity parameters over time were associated with the risk of developing type 1 diabetes. CONCLUSIONS/INTERPRETATION: It does not appear that low physical activity is a risk factor for progression from islet autoantibodies to diabetes in children and youth at high genetic risk for type 1 diabetes.
- Published
- 2022
- Full Text
- View/download PDF
5. CGM Metrics Predict Imminent Progression to Type 1 Diabetes: Autoimmunity Screening for Kids (ASK) Study
- Author
-
Andrea K, Steck, Fran, Dong, Cristy, Geno Rasmussen, Kimberly, Bautista, Flor, Sepulveda, Judith, Baxter, Liping, Yu, Brigitte I, Frohnert, Marian J, Rewers, Marian, Rewers, Aaron, Barbour, Daniel, Felipe-Morales, Paul, Dormond-Brooks, Kimberly, Driscoll, Brigitte, Frohnert, Cristy Geno, Rasmussen, Patricia, Gesualdo, Michelle, Hoffman, Rachel, Karban, Hanan, Shorrosh, Kimberly, Simmons, Andrea, Steck, Iman, Taki, Kathleen, Waugh, Edwin, Liu, Marisa, Gallant, R Brett, McQueen, and Jill M, Norris
- Subjects
Blood Glucose ,Glycated Hemoglobin ,Male ,Advanced and Specialized Nursing ,Blood Glucose Self-Monitoring ,Endocrinology, Diabetes and Metabolism ,Infant, Newborn ,Infant ,Autoimmunity ,Benchmarking ,Diabetes Mellitus, Type 1 ,Child, Preschool ,Internal Medicine ,Humans ,Female ,Child - Abstract
OBJECTIVE Children identified with stage 1 type 1 diabetes are at high risk for progressing to stage 3 (clinical) diabetes and require accurate monitoring. Our aim was to establish continuous glucose monitoring (CGM) metrics that could predict imminent progression to diabetes. RESEARCH DESIGN AND METHODS In the Autoimmunity Screening for Kids study, 91 children who were persistently islet autoantibody positive (median age 11.5 years; 48% non-Hispanic White; 57% female) with a baseline CGM were followed for development of diabetes for a median of 6 (range 0.2–34) months. Of these, 16 (18%) progressed to clinical diabetes in a median of 4.5 (range 0.4–29) months. RESULTS Compared with children who did not progress to clinical diabetes (nonprogressors), those who did (progressors) had significantly higher average sensor glucose levels (119 vs. 105 mg/dL, P < 0.001) and increased glycemic variability (SD 27 vs. 16, coefficient of variation, 21 vs. 15, mean of daily differences 24 vs. 16, and mean amplitude of glycemic excursions 43 vs. 26, all P < 0.001). For progressors, 21% of the time was spent with glucose levels >140 mg/dL (TA140) and 8% of time >160 mg/dL, compared with 3% and 1%, respectively, for nonprogressors. In survival analyses, the risk of progression to diabetes in 1 year was 80% in those with TA140 >10%; in contrast, it was only 5% in the other participants. Performance of prediction by receiver operating curve analyses showed area under the curve of ≥0.89 for both individual and combined CGM metric models. CONCLUSIONS TA140 >10% is associated with a high risk of progression to clinical diabetes within the next year in autoantibody-positive children. CGM should be included in the ongoing monitoring of high-risk children and could be used as potential entry criterion for prevention trials.
- Published
- 2021
- Full Text
- View/download PDF
6. 35-OR: Multicenter MRI Assessment of the Pancreas in Type 1 Diabetes (MAP-T1D) Predicts Progression of Type 1 Diabetes
- Author
-
JOHN VIROSTKO, JORDAN J. WRIGHT, JONATHAN M. WILLIAMS, MELISSA A. HILMES, TAYLOR M. TRIOLO, HALI C. BRONCUCIA, LIPING DU, HAKMOOK KANG, WILLIAM E. RUSSELL, LOUIS H. PHILIPSON, THOMAS KAY, HELEN E. THOMAS, SIRI ATMA W. GREELEY, ANDREA STECK, ALVIN C. POWERS, and DANIEL J. MOORE
- Subjects
Endocrinology, Diabetes and Metabolism ,Internal Medicine - Abstract
Pancreas size, as measured by MRI, is smaller at the onset of T1D and in individuals at risk for T1D. To determine whether pancreas MRI predicts T1D progression, we measured pancreas size and shape longitudinally in Type 1 Diabetes TrialNet Pathway to Prevention study participants. To increase enrollment and expand this study across multiple TrialNet sites, we established the Multicenter Assessment of the Pancreas in T1D (MAP-T1D) group to develop harmonized MRI acquisition and image processing protocols and ensure the consistency of imaging results across sites. Using this standardized protocol (PMID: 34428220) , we performed longitudinal pancreas MRI in 41 multiple autoantibody-positive individuals (mean age y.o., range 8 - 45 y.o., 49% female) at three TrialNet Clinical Centers. Average time between study entry and diabetes diagnosis for individuals who progressed to Stage 3 was 54 months while non-progressors were followed for a median time of 63 months. Five study participants who developed Stage 3 T1D during follow up had a smaller pancreas (29.5 ± 9.0 ml vs. 54.8 ± 22.5 ml, p = 0.02) and smaller pancreas volume normalized by body weight (0.61 ± 0.18 ml/kg vs. 0.85 ± 0.23 ml, p = 0.03) at study entry compared with those who did not progress to Stage 3. We found that pancreas volume was stable over time, with no significant increase or decrease up to four years after the initial MRI (total of 123 MRIs) . There was no significant change in pancreas size in the five individuals who progressed to Stage 3 T1D. The shape of the pancreas at study onset was also different in the five individuals who progressed to Stage 3 T1D compared with non-progressors, with larger surface area to volume ratio (p = 0.02) , and shorter principal axes (p = 0.05, shortest axis; p = 0.02, second shortest axis) . These data suggest that small pancreas size and altered shape predicts progression from Stage 2 to Stage 3 T1D. Disclosure J.Virostko: None. L.H.Philipson: Advisory Panel; Nevro Corp., Research Support; Dompé, Novo Nordisk, provention BIo. T.Kay: None. H.E.Thomas: Research Support; Captix Biomedical, CSL Limited, Pandion Therapeutics, Procyon Technologies. S.W.Greeley: None. A.Steck: None. A.C.Powers: None. D.J.Moore: None. J.J.Wright: None. J.M.Williams: None. M.A.Hilmes: None. T.M.Triolo: None. H.C.Broncucia: None. L.Du: None. H.Kang: None. W.E.Russell: None. Funding NIDDK (R03DK129979, U24DK097771, UC4 DK106993, DK020593) ; JDRF International (3-SRA-2015-102-M-B, 3-SRA-2019-759-M-B) ; Thomas J. Beatson, Jr. Foundation (2021-003)
- Published
- 2022
- Full Text
- View/download PDF
7. 34-OR: SARS-CoV-2 Infection Is Not Associated with Presence of Islet Autoantibodies in Children: Autoimmunity Screening for Kids (ASK)
- Author
-
CRISTY GENO RASMUSSEN, XIAOFAN JIA, HANAN SHORROSH, LIPING YU, BRIGITTE I. FROHNERT, KIMBER M. SIMMONS, ANDREA STECK, LAURA PYLE, and MARIAN REWERS
- Subjects
Endocrinology, Diabetes and Metabolism ,Internal Medicine - Abstract
Viral infections may trigger islet autoimmunity leading to type 1 diabetes (T1D) . We hypothesized SARS-CoV-2 infection is associated with presence of islet autoantibodies (IAb) in children. Between 8/2020 and 12/2021, ASK screened 47general population Colorado children aged 1-17 y for IAb to GAD, insulin, IA-2 and ZnT8 as well as antibodies to SARS-CoV-2 receptor binding domain (CoV-2 RBDAb) - a sensitive and specific marker of infection. Of those, 4172 (89%) have not previously received SARS-CoV-2 vaccine. During the study period, prevalence of CoV-2 RBDAb increased in unvaccinated from 1% to 58% and up to 100% among vaccinated. Among all children, the prevalence increased from 1% to 72% - an estimate of herd immunity (Figure) . Among the unvaccinated, prevalence of multiple or single high-affinity IAb did not differ between children positive vs. negative for CoV-2 RBDAb, respectively 1.23% (16/1297) vs. 1.00% (29/2875) , p=0.52. In multivariate logistic regression, presence of IAb was not associated with presence of CoV-2 RBDAb (OR=1.40, p=0.31) , adjusting for age, sex, race/ethnicity, and family history of T1D. While we found no association between past SARS-CoV-2 infection and islet autoimmunity, a confirmation in a larger population is warranted. Longer follow-up will help assess whether SARS-CoV2 infection accelerates progression from islet autoimmunity to diabetes. Disclosure C.Geno rasmussen: None. X.Jia: None. H.Shorrosh: None. L.Yu: None. B.I.Frohnert: Advisory Panel; Provention Bio, Inc. K.M.Simmons: Advisory Panel; Provention Bio, Inc., Consultant; Dexcom, Inc. A.Steck: None. L.Pyle: None. M.Rewers: Consultant; Janssen Research & Development, LLC, Medscape, Provention Bio, Inc., Research Support; Dexcom, Inc., JDRF, Roche Diagnostics USA. Funding JDRF 2-SRA-2021-1065-M-N
- Published
- 2022
- Full Text
- View/download PDF
8. 185-OR: T-Cell Receptor Repertoires during Type 1 Diabetes Development
- Author
-
ANGELA M. MITCHELL, ERIN E. BASCHAL, KRISTEN MCDANIEL, LAURA PYLE, KATHLEEN WAUGH, ANDREA STECK, LIPING YU, PETER GOTTLIEB, MARIAN REWERS, MAKI NAKAYAMA, and AARON W. MICHELS
- Subjects
Endocrinology, Diabetes and Metabolism ,Internal Medicine - Abstract
In type 1 diabetes (T1D) , T cells target and destroy pancreatic beta cells. T cells express T cell receptors (TCRs) which recognize peptide antigens, and each TCR is unique to a given T cell. To understand the TCR repertoire during T1D development, we used next generation sequencing to detect TCRβ chains from longitudinal peripheral blood DNA samples at four time points from genetically at-risk cases (n=29) who progressed to T1D and age/sex/HLA matched controls (n=25) beginning early in life (median age 1.4 years) in the Diabetes Autoimmunity Study in the Young (DAISY) . Over 50 million TCRβ chains were sequenced, and the repertoires became less diverse (i.e., more clonal) over time with age in both groups (p Disclosure A.M.Mitchell: None. M.Nakayama: None. A.W.Michels: Employee; ImmunoMolecular Therapeutics, Stock/Shareholder; ImmunoMolecular Therapeutics. E.E.Baschal: None. K.Mcdaniel: None. L.Pyle: None. K.Waugh: None. A.Steck: None. L.Yu: None. P.Gottlieb: Advisory Panel; Janssen Research & Development, LLC, ViaCyte, Inc., Other Relationship; IM Therapeutics, Research Support; Caladrius Biosciences, Inc., Immune Tolerance Network, National Institute of Diabetes and Digestive and Kidney Diseases, Novo Nordisk, Precigen, Inc., Tolerion, Inc. M.Rewers: Consultant; Janssen Research & Development, LLC, Medscape, Provention Bio, Inc., Research Support; Dexcom, Inc., JDRF, Roche Diagnostics USA. Funding National Institutes of Health (DK108868, DK110845, DK032083, DK032493, DK116073) Juvenile Diabetes Research Foundation (3-PDF-2020-943-A-N) Leona M. & Harry B. Helmsley Charitable Trust (2103-05093) Colorado Clinical and Translational Science Institute (TR002535)
- Published
- 2022
- Full Text
- View/download PDF
9. 1254-P: Genetic Prediction of C-Peptide Trajectory before Type 1 Diabetes Diagnosis in TrialNet
- Author
-
TAYLOR M. TRIOLO, HEMANG M. PARIKH, MUSTAFA TOSUR, PETER GOTTLIEB, RICHARD A. ORAM, SUNA ONENGUT-GUMUSCU, JEFFREY KRISCHER, STEPHEN S. RICH, ANDREA STECK, and MARIA J. REDONDO
- Subjects
Endocrinology, Diabetes and Metabolism ,Internal Medicine - Abstract
Modeling the course of C-peptide decline in autoantibody (Ab) positive individuals is important for type 1 diabetes (T1D) prediction and implementation of T1D prevention trials. Single nucleotide polymorphisms in TCF7L2, JAZF1, SLC30A8, INS, PTPRK, G6CP2, CLEC16, PTPN22 and HLA genes are associated with persistent C-peptide at or after T1D diagnosis. We sought to determine whether 12 SNPs in these genes and the T1D genetic risk score-2 (GRS2) can predict C-peptide trajectory before diagnosis of T1D. We studied Ab positive at-risk participants in the TrialNet Pathway to Prevention Study who had ImmunoChip data (N=1217, age at initial screen (mean±SD) 16.1±12.7 years, 51.5% female, 81.0% non-Hispanic white) . Over a mean follow up of 3.4±2. years, 255 (21.0%) developed multiple Ab and 336 (27.6%) developed clinical T1D. We analyzed the influence of these 12 SNPs and the T1D GRS2 on C-peptide AUC during progression from single to multiple Abs, from single Ab to clinical T1D, and from multiple Abs to clinical T1D. Analyses were adjusted for baseline C-peptide AUC, age, glucose AUC, BMI Z-score and HbA1c; the presence of high-risk HLA haplotypes (DR3 and DR4-DQ8) ; and the first 3 principal components. The type 2 diabetes (T2D) -associated TCF7L2 rs7901695 and rs4506565 SNPs were significantly associated with higher C-peptide AUC during progression from multiple Abs to T1D (p In conclusion, T2D-associated SNPs in the TCF7L2 gene and lower T1D GRS2 predict higher C-peptide particularly in progression from multiple Abs to clinical T1D. Disclosure T.M.Triolo: None. M.J.Redondo: Advisory Panel; Provention Bio, Inc. H.M.Parikh: None. M.Tosur: Advisory Panel; Provention Bio, Inc. P.Gottlieb: Advisory Panel; Janssen Research & Development, LLC, ViaCyte, Inc., Other Relationship; IM Therapeutics, Research Support; Caladrius Biosciences, Inc., Immune Tolerance Network, National Institute of Diabetes and Digestive and Kidney Diseases, Novo Nordisk, Precigen, Inc., Tolerion, Inc. R.A.Oram: Consultant; Janssen Research & Development, LLC, Research Support; Randox R & D. S.Onengut-gumuscu: None. J.Krischer: None. S.S.Rich: None. A.Steck: None. Funding NIH K12 DK094712NIH RDK121843NIH RDK124395
- Published
- 2022
- Full Text
- View/download PDF
10. New Derivatives of Ascomycin with Modifications in the Amino Acid Region - Synthesis and Biological Activities, and X-Ray Crystal Structure of 5,6-Dehydroascomycin
- Author
-
Murty A. R. C. Bulusu, Gerhard Zenke, Gerhard Schulz, Christophe Rochais, Thomas Tricotet, Andrea Steck, Peter Hiestand, Markus Bacher, Josef G. Meingassner, Trixie Wagner, Peter Waldstätten, and Walter Schuler
- Subjects
chemistry.chemical_classification ,Chemistry ,Stereochemistry ,Organic Chemistry ,Photodissociation ,X-ray ,Crystal structure ,Biochemistry ,Catalysis ,Amino acid ,Inorganic Chemistry ,Crystallography ,Drug Discovery ,X-ray crystallography ,medicine ,Ascomycin ,Physical and Theoretical Chemistry ,medicine.drug - Published
- 2009
- Full Text
- View/download PDF
11. Complete assignment of 1 H and 13 C NMR data of pravastatin derivatives
- Author
-
Andrea Steck, Karl Baumann, Sigrid Teibl, Markus Bacher, and Hermann Knapp
- Subjects
Chemistry ,Stereochemistry ,Proton NMR ,medicine ,General Materials Science ,General Chemistry ,Carbon-13 NMR ,Two-dimensional nuclear magnetic resonance spectroscopy ,Heteronuclear single quantum coherence spectroscopy ,Pravastatin ,medicine.drug - Abstract
The complete 1H and 13C NMR data of 27 pravastatin derivatives are presented. Assignment was achieved by use of 1D and 2D NMR experiments (selective 1D NOE, COSY, NOESY, HSQC, HMBC). Copyright © 2008 John Wiley & Sons, Ltd.
- Published
- 2008
- Full Text
- View/download PDF
12. Effects of Gluten Intake on Risk of Celiac Disease: A Case-Control Study on a Swedish Birth Cohort
- Author
-
Carin Andrén Aronsson, Hye-Seung Lee, Sibylle Koletzko, Ulla Uusitalo, Jimin Yang, Suvi M. Virtanen, Edwin Liu, Åke Lernmark, Jill M. Norris, Daniel Agardh, Marian Rewers, Kimberly Bautista, Judith Baxter, Ruth Bedoy, Daniel Felipe-Morales, Brigitte I. Frohnert, Patricia Gesualdo, Michelle Hoffman, Rachel Karban, Jill Norris, Adela Samper-Imaz, Andrea Steck, Kathleen Waugh, Hali Wright, Jin-Xiong She, Desmond Schatz, Diane Hopkins, Leigh Steed, Jamie Thomas, Janey Adams, Katherine Silvis, Michael Haller, Melissa Gardiner, Richard McIndoe, Ashok Sharma, Joshua Williams, Gabriela Foghis, Stephen W. Anderson, Richard Robinson, Anette G. Ziegler, Andreas Beyerlein, Ezio Bonifacio, Michael Hummel, Sandra Hummel, Kristina Foterek, Mathilde Kersting, Annette Knopff, Claudia Peplow, Roswith Roth, Joanna Stock, Elisabeth Strauss, Katharina Warncke, Christiane Winkler, Jorma Toppari, Olli G. Simell, Annika Adamsson, Heikki Hyöty, Jorma Ilonen, Sanna Jokipuu, Tiina Kallio, Miia Kähönen, Mikael Knip, Annika Koivu, Mirva Koreasalo, Kalle Kurppa, Maria Lönnrot, Elina Mäntymäki, Katja Multasuo, Juha Mykkänen, Tiina Niininen, Mia Nyblom, Petra Rajala, Jenna Rautanen, Anne Riikonen, Minna Romo, Satu Simell, Tuula Simell, Ville Simell, Maija Sjöberg, Aino Stenius, Maria Särmä, Sini Vainionpää, Eeva Varjonen, Riitta Veijola, Mari Vähä-Mäkilä, Mari Åkerlund, Maria Ask, Jenny Bremer, Ulla-Marie Carlsson, Corrado Cilio, Emelie Ericson-Hallström, Lina Fransson, Thomas Gard, Joanna Gerardsson, Rasmus Bennet, Monica Hansen, Gertie Hansson, Cecilia Harmby, Susanne Hyberg, Fredrik Johansen, Berglind Jonasdottir, Helena Elding Larsson, Sigrid Lenrick Forss, Markus Lundgren, Maria Månsson-Martinez, Maria Markan, Jessica Melin, Zeliha Mestan, Kobra Rahmati, Anita Ramelius, Anna Rosenquist, Falastin Salami, Sara Sibthorpe, Birgitta Sjöberg, Ulrica Swartling, Evelyn Tekum Amboh, Erika Trulsson, Carina Törn, Anne Wallin, Åsa Wimar, Sofie Åberg, William A. Hagopian, Michael Killian, Claire Cowen Crouch, Jennifer Skidmore, Stephen Ayres, Kayleen Dunson, Rachel Hervey, Corbin Johnson, Rachel Lyons, Arlene Meyer, Denise Mulenga, Elizabeth Scott, Joshua Stabbert, Alexander Tarr, Morgan Uland, John Willis, Dorothy Becker, Margaret Franciscus, MaryEllen Dalmagro-Elias Smith, Ashi Daftary, Mary Beth Klein, Chrystal Yates, Jeffrey P. Krischer, Michael Abbondondolo, Sarah Austin-Gonzalez, Sandra Baethke, Rasheedah Brown, Brant Burkhardt, Martha Butterworth, Joanna Clasen, David Cuthbertson, Christopher Eberhard, Steven Fiske, Dena Garcia, Jennifer Garmeson, Veena Gowda, Kathleen Heyman, Francisco Perez Laras, Shu Liu, Xiang Liu, Kristian Lynch, Jamie Malloy, Cristina McCarthy, Wendy McLeod, Steven Meulemans, Chris Shaffer, Laura Smith, Susan Smith, Noah Sulman, Roy Tamura, Kendra Vehik, Ponni Vijayakandipan, Keith Wood, Lori Ballard, David Hadley, Beena Akolkar, Kasia Bourcier, Thomas Briese, Suzanne Bennett Johnson, and Eric Triplett
- Subjects
Male ,medicine.medical_specialty ,Glutens ,Biopsy ,Teddy Study ,Diet ,Pediatric ,Wheat ,The Environmental Determinants of Diabetes in the Young ,Breastfeeding ,Gastroenterology and Hepatology ,digestive system ,Gastroenterology ,Risk Assessment ,03 medical and health sciences ,0302 clinical medicine ,GTP-Binding Proteins ,Internal medicine ,Medicine ,Humans ,Protein Glutamine gamma Glutamyltransferase 2 ,030212 general & internal medicine ,Seroconversion ,Child ,Autoantibodies ,2. Zero hunger ,chemistry.chemical_classification ,Sweden ,Transglutaminases ,Hepatology ,business.industry ,Case-control study ,nutritional and metabolic diseases ,Infant ,Odds ratio ,ta3123 ,Gluten ,digestive system diseases ,Confidence interval ,3. Good health ,Intestines ,Celiac Disease ,chemistry ,Case-Control Studies ,Child, Preschool ,Immunology ,030211 gastroenterology & hepatology ,Female ,business ,Risk assessment - Abstract
BACKGROUND & AIMS: It is not clear how intake of gluten during infancy affects subsequent risk of celiac disease. We investigated whether gluten intake before 2 years of age increases risk for celiac disease in genetically susceptible children. METHODS: We performed a case-control study of 436 pairs of children, generated from a database of 2525 children with genetic susceptibility to celiac disease in Sweden, matched for sex, birth year, and HLA genotype from September 2004 and February 2010. Children were screened annually for celiac disease using an assay for tissue transglutaminase autoantibodies (tTGA). Intestinal biopsies were collected from children who tested positive for tTGA to confirm the presence of celiac disease. Gluten intake was calculated from 3-day food records collected when the children were 9, 12, 18 and 24 months old. RESULTS: Breastfeeding duration (median 32 weeks) and age at first introduction to gluten (median 22 weeks) did not differ between cases and tTGA-negative children (controls). At the visit prior to tTGA seroconversion, cases reported a larger intake of gluten (median 4.9 g/day) than controls (median 3.9 g/day) (odds ratio [OR], 1.28; 95% confidence interval [CI], 1.13-1.46; P=.0002). More cases consumed amounts of gluten in the upper 3rd tertile (i.e. >5.0 g/day) before they tested positive for tTGA seroconversion than controls (OR, 2.65; 95% CI, 1.70-4.13; P
- Published
- 2015
13. On the reactivity of ascomycin at the binding domain. Part 3: Reactivity of the binding domain towards diazomethane
- Author
-
Karl Baumann, Klemens Hoegenauer, Andrea Steck, Hermann Knapp, Markus Bacher, and Trixie Wagner
- Subjects
Diazomethane ,Stereochemistry ,Organic Chemistry ,Biochemistry ,Product analysis ,chemistry.chemical_compound ,chemistry ,Drug Discovery ,medicine ,Reactivity (chemistry) ,Ascomycin ,X ray analysis ,medicine.drug ,Binding domain - Abstract
A thorough product analysis of the reaction of ascomycin with diazomethane has been performed. Apart from the expected oxiranes (epimeric at C9), a whole range of novel derivatives bearing various modifications in the binding domain were obtained. Proposed mechanisms for their formation and stereochemical aspects are discussed.
- Published
- 2005
- Full Text
- View/download PDF
14. Synthesis of 6-vinyl and 5-vinylproline analogues of ascomycin
- Author
-
Markus Bacher, Christophe Rochais, Andrea Steck, Murty A. R. C. Bulusu, Thomas Tricotet, and Peter Waldstätten
- Subjects
Stereochemistry ,Organic Chemistry ,Cleavage (embryo) ,Biochemistry ,chemistry.chemical_compound ,Hydrolysis ,chemistry ,Amino acid side chain ,Drug Discovery ,medicine ,Moiety ,Ascomycin ,medicine.drug ,Pipecolic acid - Abstract
6-Vinyl ( 12 ) and (5R)- and (5S)-vinylproline ( 18 , 19 ) analogues of ascomycin are synthesised starting from the known suitably protected (6S)-methoxy-9-hydroxy derivative ( 4 ) of ascomycin. The strategy involves hydrolytic cleavage of the Ce–N bond of the pipecolic acid moiety, extension of the amino acid side chain by two or one carbon units, functional group manipulations, Pd-catalysed reinstallation of the Ce–N or Cδ–N bonds, followed by deprotection and oxidation.
- Published
- 2004
- Full Text
- View/download PDF
15. On the reactivity of ascomycin at the binding domain. Part 2: Hydroxide mediated rearrangement reactions
- Author
-
Karl Baumann, Trixie Wagner, Markus Bacher, and Andrea Steck
- Subjects
Chemistry ,Stereochemistry ,Organic Chemistry ,Biochemistry ,Polyketide ,chemistry.chemical_compound ,Drug Discovery ,medicine ,Moiety ,Hydroxide ,Stereoselectivity ,Reactivity (chemistry) ,Ascomycin ,Isomerization ,medicine.drug ,Binding domain - Abstract
The natural product ascomycin represents a highly functionalised 23-membered macrocycle with a polyketide backbone. Within the binding domain, ascomycin features the unusual pattern of a masked tricarbonyl moiety, which potentially allows for high structural diversity via simple isomerisation events. Herein, highly stereoselective, hydroxide mediated rearrangement reactions at the binding domain are reported.
- Published
- 2004
- Full Text
- View/download PDF
16. Preparation and (E/Z)-Isomerization of the Diastereoisomers of Violaxanthin
- Author
-
Ferenc Zsila, Gyula Tóth, Péter Molnár, József Deli, Hanspeter Pfander, and Andrea Steck
- Subjects
Monoperphthalic acid ,Photoisomerization ,Stereochemistry ,Organic Chemistry ,Diastereomer ,Biochemistry ,Catalysis ,Inorganic Chemistry ,Zeaxanthin ,chemistry.chemical_compound ,chemistry ,Drug Discovery ,Mass spectrum ,Physical and Theoretical Chemistry ,Isomerization ,Violaxanthin - Abstract
Violaxanthin A (=(all-E,3S,5S,6R,3′S,5′S,6′R)-5,6 : 5′,6′-diepoxy-5,6,5′,6′-tetrahydro-β,β-carotene-3,3′-diol =syn,syn-violaxanthin; 5) and violaxanthin B (=(all-E,3S,5S,6R,3′S,5′R,6′S)-5,6 : 5′,6′-diepoxy-5,6,5′,6′-tetrahydro-β,β-carotene-3,3′-diol=syn,anti-violaxanthin; 6) were prepared by epoxidation of zeaxanthin diacetate (1) with monoperphthalic acid. Violaxanthins 5 and 6 were submitted to thermal isomerization and I2-catalyzed photoisomerization. The structure of the main products, i.e., (9Z)-5, (13Z)-5, (9Z)-6, (9′Z)-6, (13Z)-6, and (13′Z)-6, was determined by their UV/VIS, CD, 1H-NMR, 13C-NMR, and mass spectra.
- Published
- 2004
- Full Text
- View/download PDF
17. On the reactivity of ascomycin at the binding domain. Part 1: Liberation of the tricarbonyl portion of ascomycin
- Author
-
Annelaure Damont, Klemens Högenauer, Andrea Steck, Karl Baumann, and Markus Bacher
- Subjects
Chemistry ,Stereochemistry ,Organic Chemistry ,Structural diversity ,Biochemistry ,Drug Discovery ,medicine ,Moiety ,Liberation ,Reactivity (chemistry) ,Ascomycin ,Isomerization ,Binding domain ,medicine.drug - Abstract
Within the binding domain, ascomycin features the unusual pattern of a masked tricarbonyl moiety, which potentially allows for high structural diversity via simple isomerisation events. Herein, methodologies, allowing the liberation of the tricarbonyl unit by blocking the 14-hydroxy group are reported.
- Published
- 2003
- Full Text
- View/download PDF
18. A Convenient Protocol for Selective Cleavage of 2-Hydroxy Acid Amides. Application to Semisynthesis of the Cyclic Heptapeptide Aza HUN-7293
- Author
-
Erwin P. Schreiner, Michael Kern, and Andrea Steck
- Subjects
Models, Molecular ,Magnetic Resonance Spectroscopy ,Stereochemistry ,Ring (chemistry) ,Cleavage (embryo) ,Methylation ,Peptides, Cyclic ,Chemical synthesis ,Catalysis ,Structure-Activity Relationship ,chemistry.chemical_compound ,Amide ,Cell Adhesion ,Combinatorial Chemistry Techniques ,Amino Acid Sequence ,Chemoselectivity ,Depsipeptide ,chemistry.chemical_classification ,Molecular Structure ,Organic Chemistry ,Substrate (chemistry) ,General Medicine ,Transesterification ,Amides ,Semisynthesis ,Cyclic peptide ,Amino acid ,chemistry ,Cyclization ,Yield (chemistry) ,Hydroxy Acids ,Saponification - Abstract
A two-step protocol for the first chemoselective cleavage of 2-hydroxy acid amides has been developed. Mesylation of the model substrate 2-(hydroxypropionylamino)-4-methylpentanoic acid methyl ester (11) followed by treatment with N-ethylthiourea (13) allows cleavage of 2-hydroxy acid amides under smooth conditions. Successful application of this methodology to the open-chain transesterification product 15 (methylester) of the cyclic heptadepsipeptide HUN-7293, a potent inhibitor of inducible cell adhesion molecule expression, delivered the corresponding hexapeptide 18 with unprotected N-terminus in 70-75% yield. This result demonstrates that the protocol developed even works in the presence of an ester and several methylated and unmethylated amide bonds. Finally, a sequence of ligation of methyl D-dehydroglutaminate (20) to the C-terminus of the saponification product 21, followed by the degradation protocol and ring closure, allowed chemical "point mutation" at the DGCN site affording the aza analogue of HUN-7293 (24) in 15% overall yield. To the best of our knowledge this is the first report on chemoselective cleavage of 2-hydroxy acid amides.
- Published
- 2002
- Full Text
- View/download PDF
19. NMR study on 9-Sand 9-Roxirane derivatives of ascomycin
- Author
-
Klemens Högenauer, Andrea Steck, Karl Baumann, and Gerhard Schulz
- Subjects
Stereochemistry ,Absolute configuration ,General Chemistry ,Nuclear magnetic resonance spectroscopy ,chemistry.chemical_compound ,chemistry ,Heteronuclear molecule ,Amide ,medicine ,General Materials Science ,Ascomycin ,Spectroscopy ,Two-dimensional nuclear magnetic resonance spectroscopy ,medicine.drug - Abstract
Structure elucidation of 9-S and 9-R oxirane derivatives of ascomycin, a 23-membered immunomodulating macrolactam, was performed using NMR spectroscopy. The total 1H and 13C signal assignments required the gradient-selected versions of COSY (gs-COSY), heteronuclear multiple quantum-correlation spectroscopy (gs-HSQC), heteronuclear multiple-bond correlation spectroscopy (gs-HMBC), and nuclear Overhauser methods. The data sets then were used to examine the dependence of ketone–hemiketal and cis–trans amide equilibria on the substitution pattern and the absolute configuration of the chiral oxirane. Copyright © 2002 John Wiley & Sons, Ltd.
- Published
- 2002
- Full Text
- View/download PDF
20. Obesity in Youth with Type 1 Diabetes in Germany, Austria, and the United States
- Author
-
Stephanie N. DuBose, Julia M. Hermann, William V. Tamborlane, Roy W. Beck, Axel Dost, Linda A. DiMeglio, Karl Otfried Schwab, Reinhard W. Holl, Sabine E. Hofer, David M. Maahs, Steven Willi, Terri Lipman, Tammy Calvano, Olena Kucheruk, Pantea Minnock, Chau Nguyen, Georgeanna Klingensmith, Carolyn Banion, Jennifer Barker, Cindy Cain, Peter Chase, Sandy Hoops, Megan Kelsy, David Maahs, Cathy Mowry, Kristen Nadeau, Jennifer Raymond, Marian Rewers, Arleta Rewers, Robert Slover, Andrea Steck, Paul Wadwa, Philippe Walravens, Philip Zeitler, Heidi Haro, Katherine Manseau, Ruth Weinstock, Roberto Izquierdo, Umair Sheikh, Patricia Conboy, Jane Bulger, Suzan Bzdick, Robin Goland, Rachelle Gandica, Lindsay Weiner, Steve Cook, Ellen Greenberg, Kevin Kohm, Sarah Pollack, Joyce Lee, Brigid Gregg, Meng Tan, Kimberly Burgh, Ashley Eason, Satish Garg, Aaron Michels, Lisa Myers, Linda DiMeglio, Tamara Hannon, Donald Orr, Christy Cruz, Stephanie Woerner, Joseph Wolfsdorf, Maryanne Quinn, Olivia Tawa, Andrew Ahmann, Jessica Castle, Farahnaz Joarder, Chris Bogan, Nancy Cady, Jennifer Cox, Amy Pitts, Rebecca Fitch, Brad White, Bethany Wollam, Bruce Bode, Katie Lindmark, RaShonda Hosey, Kathleen Bethin, Teresa Quattrin, Michelle Ecker, Jamie Wood, Lily Chao, Clement Cheung, Lynda Fisher, Debra Jeandron, Francine Kaufman, Mimi Kim, Brian Miyazaki, Roshanak Monzavi, Payal Patel, Pisit Pitukcheewanont, Anna Sandstrom, Marisa Cohen, Brian Ichihara, Megan Lipton, Ayse Cemeroglu, Yaw Appiagyei-Dankah, Maala Daniel, Daniel Postellon, Michael Racine, Michael Wood, Lora Kleis, Irl Hirsch, Anthony DeSantis, D.C. Dugdale, R. Alan Failor, Lisa Gilliam, Carla Greenbaum, Mary Janci, Peggy Odegard, Dace Trence, Brent Wisse, Emily Batts, Angela Dove, Deborah Hefty, Dori Khakpour, Jani Klein, Kristen Kuhns, Marli McCulloch-Olson, Christina Peterson, Mary Ramey, Marissa St. Marie, Pam Thomson, Christine Webber, David Liljenquist, Mark Sulik, Carl Vance, Tiffany Coughenour, Chris Brown, Jean Halford, Andrea Prudent, Shanda Rigby, Brandon Robison, Harold Starkman, Tymara Berry, Barbara Cerame, Daisy Chin, Laurie Ebner-Lyon, Frances Guevarra, Kristen Sabanosh, Lawrence Silverman, Christine Wagner, Marie Fox, Bruce Buckingham, Avni Shah, Kimberly Caswell, Breanne Harris, Richard Bergenstal, Amy Criego, Greg Damberg, Glenn Matfin, Margaret Powers, David Tridgell, Cassie Burt, Beth Olson, LeeAnn Thomas, Sanjeev Mehta, Michelle Katz, Lori Laffel, Joanne Hathway, Roxanne Phillips, Eda Cengiz, William Tamborlane, Darryll Cappiello, Amy Steffen, Melinda Zgorski, Anne Peters, Valerie Ruelas, Robert Benjamin, Deanna Adkins, Juanita Cuffee, Amber Spruill, Grazia Aleppo-Kacmarek, Teresa Derby, Elaine Massaro, Kimberly Webb, Christine Burt Solorzano, Mark DeBoer, Helen Madison, Janet McGill, Lori Buechler, Mary Jane Clifton, Stacy Hurst, Sarah Kissel, Carol Recklein, Eva Tsalikian, Michael Tansey, Joanne Cabbage, Julie Coffey, Sarah Salamati, Mark Clements, Sripriya Raman, Angela Turpin, Jennifer Bedard, Cyndy Cohoon, Aliza Elrod, Amanda Fridlington, Lois Hester, Davida Kruger, Desmond Schatz, Michael Clare-Salzler, Kenneth Cusi, Colleen Digman, Becky Fudge, Mike Haller, Collette Meehan, Henry Rohrs, Janet Silverstein, Sujata Wagh, Miriam Cintron, Eleni Sheehan, Jamie Thomas, Mark Daniels, Susan Clark, Timothy Flannery, Nikta Forghani, Ajanta Naidu, Christina Reh, Peggy Scoggin, Lien Trinh, Natalie Ayala, Rebeca Quintana, Heather Speer, William Zipf, Diane Seiple, Julie Kittelsrud, Ashutosh Gupta, Vikki Peterson, Ashley Stoker, Michael Gottschalk, Marla Hashiguchi, Katheryn Smith, Henry Rodriguez, Craig Bobik, Danielle Henson, Jill Simmons, Amy Potter, Margo Black, Faith Brendle, Rose Gubitosi-Klug, Beth Kaminski, Susan Bergant, Wendy Campbell, Catherine Tasi, Kenneth Copeland, Joni Beck, Joane Less, Jill Schanuel, Jennifer Tolbert, Saleh Adi, Andrea Gerard-Gonzalez, Stephen Gitelman, Nassim Chettout, Christine Torok, Catherine Pihoker, Joyce Yi-Frazier, Susan Kearns, Ingrid Libman, Vicky Bills, Ana Diaz, Julie Duke, Brandon Nathan, Antoinette Moran, Melena Bellin, Shannon Beasley, Anne Kogler, Janice Leschyshyn, Kara Schmid, Anne Street, Bryce Nelson, Carrie Frost, Erin Reifeis, Morey Haymond, Fida Bacha, Maria Caldas-Vasquez, Sara Klinepeter, Maria Redondo, Rosa Berlanga, Teresa Falk, Elizabeth Garnes, Janette Gonzalez, Cecilia Martinez, Mariam Pontifes, Ronald Yulatic, Kathleen Arnold, Traci Evans, Sharon Sellers, Vandana Raman, Carol Foster, Mary Murray, Trina Brown, Hillarie Slater, Karen Wheeler, David Harlan, Mary Lee, John-Paul Lock, Celia Hartigan, Lisa Hubacz, John Buse, Ali Calikoglu, Joseph Largay, Laura Young, Helen Brown, Vinnie Duncan, Michelle Duclos, Julie Tricome, Verdayne Brandenburg, Julie Blehm, Julie Hallanger-Johnson, Dawn Hanson, Corliss Miller, Jennifer Weiss, Robert Hoffman, Monika Chaudhari, David Repaske, Elizabeth Gilson, Jesse Haines, Justen Rudolph, Charles McClave, Doris Biersdorf, Anthony Tello, Donna Amundson, Rhonda Ward, Michael Rickels, Cornelia Dalton-Bakes, Eileen Markman, Amy Peleckis, Nora Rosenfeld, Lawrence Dolan, Sarah Corathers, Jessica Kichler, Holly Baugh, Debbie Standiford, Jeanne Hassing, Jennifer Jones, Stephen Willis, Carol Wysham, Lisa Davis, Scott Blackman, Kimber-Lee Abel, Loretta Clark, Andrea Jonas, Ellie Kagan, Jay Sosenko, Carlos Blashke, Della Matheson, Rachel Edelen, Thomas Repas, Denise Baldwin, Trista Borgwardt, Christina Conroy, Kelly DeGrote, Rod Marchiando, Michelle Wasson, Larry Fox, Nelly Mauras, Ligeia Damaso, Kim Englert, Marwan Hamaty, Laurence Kennedy, Michelle Schweiger, Pantelis Konstantinopoulos, Carolyn Mawhorter, Amy Orasko, Denise Rose, Larry Deeb, Kim Rohrbacher, Leroy Schroeder, Amanda Roark, Omar Ali, Joanna Kramer, Donna Whitson-Jones, Heidi Gassner, Sobha Kollipara, Katerina Harwood, Vijaya Prasad, and Judy Brault
- Subjects
Male ,Pediatrics ,medicine.medical_specialty ,endocrine system diseases ,Adolescent ,MEDLINE ,Hypoglycemia ,Body Mass Index ,Diabetes mellitus ,Germany ,medicine ,Humans ,Obesity ,Registries ,Child ,Glycemic ,Glycated Hemoglobin ,Type 1 diabetes ,business.industry ,nutritional and metabolic diseases ,medicine.disease ,Institutional review board ,United States ,Diabetes Mellitus, Type 1 ,Austria ,Child, Preschool ,Pediatrics, Perinatology and Child Health ,Female ,business ,Body mass index ,Demography - Abstract
To examine the current extent of the obesity problem in 2 large pediatric clinical registries in the US and Europe and to examine the hypotheses that increased body mass index (BMI) z-scores (BMIz) are associated with greater hemoglobin A1c (HbA1c) and increased frequency of severe hypoglycemia in youth with type 1 diabetes (T1D).International (World Health Organization) and national (Centers for Disease Control and Prevention/German Health Interview and Examination Survey for Children and Adolescents) BMI references were used to calculate BMIz in participants (age 2-18 years and ≥ 1 year duration of T1D) enrolled in the T1D Exchange (n = 11,435) and the Diabetes Prospective Follow-up (n = 21,501). Associations between BMIz and HbA1c and severe hypoglycemia were assessed.Participants in both registries had median BMI values that were greater than international and their respective national reference values. BMIz was significantly greater in the T1D Exchange vs the Diabetes Prospective Follow-up (P.001). After stratification by age-group, no differences in BMI between registries existed for children 2-5 years, but differences were confirmed for 6- to 9-, 10- to 13-, and 14- to 17-year age groups (all P.001). Greater BMIz were significantly related to greater HbA1c levels and more frequent occurrence of severe hypoglycemia across the registries, although these associations may not be clinically relevant.Excessive weight is a common problem in children with T1D in Germany and Austria and, especially, in the US. Our data suggest that obesity contributes to the challenges in achieving optimal glycemic control in children and adolescents with T1D.
- Published
- 2014
21. Regioselective Carbon–Carbon Bond Formation in the Effector Domain of Ascomycin
- Author
-
Ewald Haidl, Maximilian Grassberger, Andrea Steck, Hildegard Sperner, Amarylla Horvath, and Gerhard Schulz
- Subjects
chemistry.chemical_classification ,Double bond ,Stereochemistry ,Organic Chemistry ,Regioselectivity ,chemistry.chemical_element ,Biochemistry ,Rhodium ,chemistry.chemical_compound ,chemistry ,Aldol reaction ,Carbon–carbon bond ,Drug Discovery ,medicine ,Enol ether ,Ascomycin ,Derivative (chemistry) ,medicine.drug - Abstract
Starting from 33- O -silyl-protected ascomycin or its 23,24-dehydration product, regio- and stereo-selective formal aldol reactions under carbon–carbon bond formation at C-22, C-23, or C-24 are demonstrated. Additionally, with the 22-silyl enol ether ascomycin derivative a rhodium(I)-catalysed shift of the 19,20 double bond into the 19,38 exocyclic position is observed at elevated temperature.
- Published
- 2000
- Full Text
- View/download PDF
22. Partial Synthesis and Characterization of Karpoxanthins and Cucurbitaxanthin A Epimers
- Author
-
Gyula Tóth, Péter Molnár, Jozsef Deli, Zoltán Matus, Andrea Steck, and Hanspeter Pfander
- Subjects
Inorganic Chemistry ,Stereochemistry ,Computational chemistry ,Chemistry ,Organic Chemistry ,Drug Discovery ,Epimer ,Physical and Theoretical Chemistry ,Biochemistry ,Catalysis ,Characterization (materials science) - Published
- 1999
- Full Text
- View/download PDF
23. Isolation and Structural Elucidation of (13Z,13‘Z,3R,3‘R,6‘R)-Lutein from Marigold Flowers, Kale, and Human Plasma
- Author
-
and Andrea Steck, Hanspeter Pfander, and Frederick Khachik
- Subjects
endocrine system ,Lutein ,Magnetic Resonance Spectroscopy ,Chemical structure ,Brassica ,High-performance liquid chromatography ,chemistry.chemical_compound ,Carotenoid ,Chromatography, High Pressure Liquid ,Legume ,chemistry.chemical_classification ,Plants, Medicinal ,Chromatography ,biology ,Plant Extracts ,food and beverages ,Stereoisomerism ,General Chemistry ,Carbon-13 NMR ,biology.organism_classification ,eye diseases ,chemistry ,Brassica oleracea ,Spectrophotometry, Ultraviolet ,sense organs ,General Agricultural and Biological Sciences ,Saponification - Abstract
(13Z,13'Z,3R,3'R,6'R)-Lutein has been isolated and purified from extracts of marigold flowers, fresh raw kale (Brassica oleracea var. Acephala), and human plasma and fully characterized by (1)H and (13)C NMR, UV/vis, and MS. While the concentration of (13Z, 13'Z)-lutein in kale and human plasma compared to (all-E,3R,3'R, 6'R)-lutein was found to be quite low, this compound was readily isolated by fractional crystallization of lutein from marigold extracts. Thus, the mother liquors from two consecutive crystallizations of lutein from a saponified extract of marigold flowers were enriched in (13Z,13'Z)-lutein (8.7% of total carotenoids) and employed for the isolation of this compound by HPLC. The identity of the di-Z-lutein in kale and human plasma has been established by comparison of the HPLC-UV/vis-MS profiles of the purified compounds with those of a fully characterized sample, isolated from marigolds. 3-Hydroxy-beta,epsilon-caroten-3'-one and 3'-epilutein have also been identified in extracts from marigolds.
- Published
- 1999
- Full Text
- View/download PDF
24. Carotenoids from Guava (Psidium guajava L.): Isolation and Structure Elucidation
- Author
-
and Andrea Steck, Hanspeter Pfander, and Adriana Zerlotti Mercadante
- Subjects
chemistry.chemical_classification ,Psidium ,Molecular Structure ,biology ,Stereochemistry ,Spectrum Analysis ,Chemical structure ,Myrtaceae ,General Chemistry ,Carbon-13 NMR ,biology.organism_classification ,Carotenoids ,Phytofluene ,chemistry.chemical_compound ,Pigment ,chemistry ,Fruit ,visual_art ,Proton NMR ,visual_art.visual_art_medium ,Food science ,General Agricultural and Biological Sciences ,Carotenoid - Abstract
Sixteen carotenoids were isolated from the flesh of Brazilian red guavas (Psidium guajava L.). Their structures were established by means of UV−visible, 400 and 500 MHz 1H NMR, 120 and 125 MHz 13C NMR, mass, and circular dichroism spectra. The carotenoids were identified as phytofluene, (all-E)-, (9Z)-, (13Z)-, and (15Z)-β-carotene, (all-E)-γ-carotene, (all-E)-, (9Z)-, (13Z)-, and (15Z)-lycopene, (all-E,3R)-β-cryptoxanthin, (all-E,3R)-rubixanthin, (all-E,3S,5R,8S)-cryptoflavin, (all-E,3R,3‘R,6‘R)-lutein, (all-E,3S,5R,6R,3‘S,5‘R,8‘R)-, and (all-E,3S,5R,6R,3‘S,5‘R,8‘S)-neochrome. Thirteen of the carotenoids identified are reported as guava carotenoids for the first time. Keywords: Carotenoids; isolation; LC/MS; NMR; guava; Psidium guajava L.
- Published
- 1998
- Full Text
- View/download PDF
25. Partial Synthesis and Structural Elucidation of the Oxidative Metabolites of Lycopene Identified in Tomato Paste, Tomato Juice, and Human Serum
- Author
-
Urs A. Niggli, Hanspeter Pfander, Frederick Khachik, and Andrea Steck
- Subjects
chemistry.chemical_classification ,Chromatography ,Metabolite ,Diastereomer ,General Chemistry ,Metabolism ,Pharmacognosy ,Chemical synthesis ,Lycopene ,chemistry.chemical_compound ,Hydrolysis ,chemistry ,Biochemistry ,General Agricultural and Biological Sciences ,Carotenoid - Abstract
Two oxidative metabolites of lycopene in tomato paste, tomato juice, and human serum have been prepared by partial synthesis from oxidation of lycopene with m-chloroperbenzoic acid (MCPBA) followed by acidic hydrolysis. Extensive 1H and 13C NMR spectroscopy studies of the purified products of these reactions have confirmed that the major oxidation products of lycopene (I) are lycopene 1,2-epoxide (II) and lycopene 5,6-epoxide (III) (tentative assignment). Several diepoxides of lycopene, namely, lycopene 1,2;5,6-diepoxide (IV), lycopene 1,2;5‘,6‘-diepoxide (V), lycopene 5,6;5‘,6‘-diepoxide (VI), and lycopene 1,2;1‘,2‘-diepoxide (VII), which were formed as minor products, were tentatively identified. Whereas lycopene 1,2-epoxide was found to be fairly stable, lycopene 5,6-epoxide underwent cyclization to form a mixture of diastereomeric epoxides A (VIII, major) and B (IX, minor). The trivial names of 2,6-cyclolycopene-1,5-epoxides A (VIII) and B (IX) have been assigned to these compounds with a novel five-m...
- Published
- 1998
- Full Text
- View/download PDF
26. Aesculaxanthin, a New Carotenoid Isolated from Pollens ofAesculus hippocastanum
- Author
-
Urs Niggli, Zoltán Matus, Hanspeter Pfander, Andrea Steck, Péter Molnár, Gyula Tóth, and József Deli
- Subjects
Inorganic Chemistry ,chemistry.chemical_classification ,Aesculus hippocastanum ,chemistry ,Organic Chemistry ,Drug Discovery ,Botany ,Physical and Theoretical Chemistry ,Biochemistry ,Carotenoid ,Catalysis - Published
- 1998
- Full Text
- View/download PDF
27. Isolation and characterization of 3,5,6-trihydroxy-carotenoids from petals ofLilium tigrinum
- Author
-
J. Deli, Andrea Steck, Z. Matus, Gy. Tóth, Hanspeter Pfander, and Péter Molnár
- Subjects
chemistry.chemical_classification ,Chromatography ,biology ,Lilium ,Stereochemistry ,Liliaceae ,Organic Chemistry ,Clinical Biochemistry ,Absolute configuration ,biology.organism_classification ,Biochemistry ,High-performance liquid chromatography ,Analytical Chemistry ,chemistry ,Epimer ,Petal ,Carotenoid - Abstract
Reinvestigation by HPLC of the petals ofLilium tigrinum and the isolation of some minor compounds is reported. Using HPLC-controlled, preparative-column chromatography, 5,6-diakarpoxanthin (6), 6-epikarpoxanthin (2), 5,6-diacapsokarpoxanthin (8), and 9Z-antheraxanthin (9Z-13) were isolated and characterized. Based on spectroscopic data the absolute configurations of6 and8 were identical with those originating from paprika, thus the 5,6-diakarpoxanthin (6) and 5,6-diacapsokarpoxanthin (8) have the 3S, 5S, 6S configuration and 6-epikarpoxanthin (2) has the 3S, 5R, 6S configuration.
- Published
- 1998
- Full Text
- View/download PDF
28. Partial Synthesis and Characterization of Capsokarpoxanthins and 3,6-Epoxcapsanthins
- Author
-
Hanspeter Pfander, Péter Molnár, Andrea Steck, József Deli, Zoltán Matus, and Gyula Tóth
- Subjects
Inorganic Chemistry ,Hydrolysis ,Chemistry ,Organic Chemistry ,Drug Discovery ,Polymer chemistry ,Mass spectrum ,Organic chemistry ,Physical and Theoretical Chemistry ,Biochemistry ,Catalysis ,Characterization (materials science) - Abstract
The acid-catalyzed hydrolysis of (3S,5R,6S,3′S,5′R)-5,6-epoxycapsanthin (5) led to (3S,5R,6R,3′S,5′R)-(7) and (3S,5R,6S,3′S,5′R)-capsokarpoxanthin (8). In addition, (3S,5R,8R,3′S,5′R)- (9), (3S,5R,8S,3′S,5′R)-capsochrome (10), and (3S,5R,6R,3′S,5′R)-3,6-epoxycapsanthin (6) afforded (3S,5S,6R,3′S,5′R)-capsokarpoxanthin (12) (3S,5S,8S,3′S,5′R)- (13) and (3S,5S,8R,3′S,5′S)-capsochrome (14) as well as (3S,5S,6R,3′S,5′R)-3,6-epoxyepicapsanthin (15). Compounds 5–15 were isolated in crystalline form and characterized by their UV/VIS, CD, 1H- and 13C-NMR, and mass spectra.
- Published
- 1998
- Full Text
- View/download PDF
29. Isolation of Carotenoids with 3,5,6-Trihydroxy-5,6-dihydro-β-end Groups from Red Paprika (Capsicum annuum)
- Author
-
József Deli, Gyula Tóth, Andrea Steck, Zoltán Matus, Hanspeter Pfander, and Péter Molnár
- Subjects
Inorganic Chemistry ,chemistry.chemical_classification ,Capsicum annuum ,Chemistry ,Organic Chemistry ,Drug Discovery ,Food science ,Physical and Theoretical Chemistry ,Isolation (microbiology) ,Biochemistry ,Carotenoid ,Catalysis - Abstract
6-Epikarpoxanthin ((all-E,3S,5R,6S,3′R)-5,-6-dihydro-β,β-carotene-3,5,6,3′-tetrol, 5), 5,6-diepikarpoxanthin ((all-E,3S,5S,6S,3′R)-5,6-β,β-carotene-3,5,6,3′-tetrol, 13), 5,6-diepilatoxanthin ((all-E,3S,5S,6S,3′S5′R,6′S)-5,6′-epoxy-5,6,5′,6′-tetrahydro-β,β-carotene-3,5,6,3′-tetrol, 14), and 5,6-diepicapsokarpoxanthin ((all-E,3S,5S,6S,3′S,5′R)-5,6-dihydro-3,5,6,3′-tetrahydroxy-β,κ-caroten-6′-one, 15) were isolated from red spice paprika (Capsicum annuum var. longum) and characterized by their UV/VIS, CD, 1H- and 13C-NMR, and mass spectra. Our investigations demonstrate that the configuration of the 3,5,6-trihydroxy-5,6-dihydro-β-end group may differ depending on the biological source.
- Published
- 1998
- Full Text
- View/download PDF
30. Oxidation of carotenoids — I. Dihydrooxepin derivatives as products of oxidation of canthaxanthin and β,β-carotene
- Author
-
Urs Niggli, Marcel Zürcher, Andrea Steck, and Hanspeter Pfander
- Subjects
chemistry.chemical_classification ,chemistry.chemical_compound ,chemistry ,medicine.medical_treatment ,Organic Chemistry ,Drug Discovery ,Carotene ,medicine ,Organic chemistry ,Canthaxanthin ,Molecular oxygen ,Biochemistry ,Carotenoid - Abstract
Dihydrooxepin derivatives 1 and 2 were obtained by oxidation of canthaxanthin with m-CPBA and of β,β-carotene with molecular oxygen, respectively.
- Published
- 1997
- Full Text
- View/download PDF
31. Partial Synthesis and Characterization of the Mono-and Diepoxides of β-Cryptoxanthin
- Author
-
Gyula Tóth, Péter Molnár, Zoltán Matus, Andrea Steck, Hanspeter Pfander, and József Deli
- Subjects
chemistry.chemical_classification ,Natural product ,Organic Chemistry ,β cryptoxanthin ,Biochemistry ,Catalysis ,law.invention ,Inorganic Chemistry ,Hydrolysis ,chemistry.chemical_compound ,Capsicum annuum ,chemistry ,Acetylation ,law ,Drug Discovery ,Mass spectrum ,Organic chemistry ,Physical and Theoretical Chemistry ,Crystallization ,Carotenoid - Abstract
β-Cryptoxanthin (1) was acetylated and then epoxidized with monoperoxyphthalic acid. After hydrolysis, repeated chromatography, and crystallization, (3S,5R,6S)-5,6-epoxy-β-cryptoxanthin (3), (3S,5S,6R)-5,6-epoxy-β-cryptoxanthin (4), (3R,5′R,6′R)-5′,6′-epoxy-β-cryptoxanthin (5), (3S,5R,6S,5′R,6′S)-5,6:5′,6′-diepoxy-β-cryp-toxanthin (6), and (3S,5S,6R,5′S,6′R)-5,6:5′,6′-diepoxy-β-cryptoxanthin (7) were isolated as main products and characterized by their UV/VIS, CD, 1H- and 13C-NMR, and mass spectra. The comparison of the carotenoid isolated from yellow, tomato-shaped paprika (Capsicum annuum var. lycopersiciforme flavum) with 3–5 strongly supports the structure of 3 for the natural product.
- Published
- 1997
- Full Text
- View/download PDF
32. A contrast between children and adolescents with excellent and poor control: the T1D Exchange clinic registry experience
- Author
-
Meredith S, Campbell, Desmond A, Schatz, Vincent, Chen, Jenise C, Wong, Andrea, Steck, William V, Tamborlane, Jennifer, Smith, Roy W, Beck, Eda, Cengiz, Lori M, Laffel, Kellee M, Miller, Michael J, Haller, and Vijaya, Prasad
- Subjects
Blood Glucose ,Glycated Hemoglobin ,Male ,Adolescent ,Ambulatory Care Facilities ,Hypoglycemia ,United States ,Article ,Diabetic Ketoacidosis ,Self Care ,Diabetes Mellitus, Type 1 ,Socioeconomic Factors ,Humans ,Female ,Registries ,Child - Abstract
Optimizing glycemic control in pediatric type 1 diabetes (T1D) is essential to minimizing long-term risk of complications. We used the T1D Exchange database from 58 US diabetes clinics to identify differences in diabetes management characteristics among children categorized as having excellent vs. poor glycemic control.Among registry participants 6-17 yr old with diabetes duration ≥ 2 yr, those with excellent control [(A1c7%)(53 mmol/mol) (N = 588)] were compared with those with poor control [(A1c ≥ 9% )(75 mmol/mol) (N = 2684)] using logistic regression.The excellent and poor control groups differed substantially in diabetes management (p0.001 for all) with more of the excellent control group using insulin pumps, performing blood glucose monitoring ≥ 5 ×/d, missing fewer boluses, bolusing before meals rather than at the time of or after a meal, using meal-specific insulin:carbohydrate ratios, checking their blood glucose prior to giving meal time insulin, giving insulin for daytime snacks, giving more bolus insulin, and using a lower mean total daily insulin dose than those in poor control. After adjusting for demographic and socioeconomic factors, diabetes management characteristics were still strongly associated with good vs. poor control. Notably, frequency of severe hypoglycemia was similar between the groups while DKA was more common in the poorly controlled group.Children with excellent glycemic control tend to exhibit markedly different diabetes self-management techniques than those with poor control. This knowledge may further inform diabetes care providers and patients about specific characteristics and behaviors that can be augmented to potentially improve glycemic control.
- Published
- 2013
33. Isomerisierung von (all-E)-Cycloviolaxanthin Herstellung und Charakterisierung von (9Z)-und (13Z)-Cycloviolaxanthin
- Author
-
Zoltán Matus, Andrea Steck, József Deli, Gyula Tóth, and Péter Molnár
- Subjects
Inorganic Chemistry ,Capsicum annuum ,Circular dichroism ,Chemistry ,Organic Chemistry ,Drug Discovery ,Polymer chemistry ,Physical and Theoretical Chemistry ,Biochemistry ,Isomerization ,Catalysis - Abstract
Isomerization of (all-E)-Cycloviolaxanthin. Preparation and Characterization of (9Z)- and (13Z)-Cycloviolaxanthin From (all-E)-cycloviolaxanthin (ex Capsicum annuum), (9Z)- and (13Z)-cycloviolaxanthin were prepared in a highly pure state. The configuration of both isomers was determined by means of UV/VIS, NMR, and CD spectroscopy.
- Published
- 1996
- Full Text
- View/download PDF
34. Reisolation of Carotenoid 3,6-Epoxides from Red Paprika (Capsicum annuum)
- Author
-
Gyula Tóth, József Deli, Zoltán Matus, Péter Molnár, and Andrea Steck
- Subjects
Inorganic Chemistry ,chemistry.chemical_classification ,Capsicum annuum ,Horticulture ,chemistry ,Organic Chemistry ,Drug Discovery ,Physical and Theoretical Chemistry ,Cycloviolaxanthin ,Biochemistry ,Carotenoid ,Catalysis - Abstract
Cucurbitaxanthin A (= (3S,5R,6R,3′R)-3,6-epoxy-5,6-dihydro-β,β- carotene-5,3′-diol; 5), cucurbitaxanthin B (= (3S,5R,6R,3′S,5′R,6′S)-3,6,5′, 6′-diepoxy-5,6,5′,6′-tetrahydro-β,β-carotene-5,3′-diol; 6), the epimeric cucurbitachromes 1 and 2 (= (3S,5R,6R,3′S,5′R,8′S)- and (3S,5R,6R,3′S,5′R,8′R)-3,6,5′, 8′-diepoxy-5,6,5′,6′-tetrahydro-β,β-carotene-5,3′-diol, resp.; 9/10), cycloviolaxanthin (= (3S,5R,6R,3′S,5′R,6′R)-3,6,3′, 6′-diepoxy-5,6,5′,6′-tetrahydro-β,κs-carotene-5,5′-diol; 8), and capsanthin 3,6-epoxide (= (3S,5R,6R,3′S,5′R)-3,6-epoxy-5,6-dihydro −5,3′-dihydroxy-β,κ-caroten-6′-one; 7) were isolated from red spice paprika (Capsicum annuum var. longum) and characterized by their 1H- and 13C-NMR, mass, and CD spectra.
- Published
- 1996
- Full Text
- View/download PDF
35. Selective transformation of ascomycin into 11-epi-ascomycin
- Author
-
Annelaure Damont, Andrea Steck, Markus Bacher, and Karl Baumann
- Subjects
Stereochemistry ,Chemistry ,Organic Chemistry ,Drug Discovery ,medicine ,Structural diversity ,Moiety ,Ascomycin ,Biochemistry ,Binding domain ,medicine.drug - Abstract
Within the binding domain, ascomycin features the unusual pattern of a masked tricarbonyl moiety, which potentially allows for high structural diversity via simple isomerisation events. A cascade of diastereoselective rearrangement reactions at the binding domain, allowing the conversion of ascomycin into 11- epi -ascomycin is herein reported.
- Published
- 2004
- Full Text
- View/download PDF
36. ChemInform Abstract: Carotenoids from Annatto. Part 3. Isolation and Structure Elucidation of Minor Carotenoids from Annatto (Bixa orellana L.) Seeds
- Author
-
Adriana Zerlotti Mercadante, Hanspeter Pfander, and Andrea Steck
- Subjects
chemistry.chemical_classification ,Terpene ,Bixa ,chemistry ,biology ,Organic chemistry ,General Medicine ,Food science ,Isolation (microbiology) ,biology.organism_classification ,Carotenoid - Published
- 2010
- Full Text
- View/download PDF
37. ChemInform Abstract: Isolation of Carotenoids with 3,5,6-Trihydroxy-5,6-dihydro-β-end Groups from Red Paprika (Capsicum annuum)
- Author
-
Gyula Tóth, Hanspeter Pfander, Péter Molnár, Andrea Steck, József Deli, and Zoltán Matus
- Subjects
Terpene ,chemistry.chemical_classification ,Capsicum annuum ,chemistry ,General Medicine ,Food science ,Isolation (microbiology) ,Carotenoid - Abstract
6-Epikarpoxanthin ((all-E,3S,5R,6S,3′R)-5,-6-dihydro-β,β-carotene-3,5,6,3′-tetrol, 5), 5,6-diepikarpoxanthin ((all-E,3S,5S,6S,3′R)-5,6-β,β-carotene-3,5,6,3′-tetrol, 13), 5,6-diepilatoxanthin ((all-E,3S,5S,6S,3′S5′R,6′S)-5,6′-epoxy-5,6,5′,6′-tetrahydro-β,β-carotene-3,5,6,3′-tetrol, 14), and 5,6-diepicapsokarpoxanthin ((all-E,3S,5S,6S,3′S,5′R)-5,6-dihydro-3,5,6,3′-tetrahydroxy-β,κ-caroten-6′-one, 15) were isolated from red spice paprika (Capsicum annuum var. longum) and characterized by their UV/VIS, CD, 1H- and 13C-NMR, and mass spectra. Our investigations demonstrate that the configuration of the 3,5,6-trihydroxy-5,6-dihydro-β-end group may differ depending on the biological source.
- Published
- 2010
- Full Text
- View/download PDF
38. ChemInform Abstract: Partial Synthesis and Characterization of Capsokarpoxanthins and 3,6-Epoxycapsanthins
- Author
-
Péter Molnár, Zoltán Matus, Gyula Tóth, Andrea Steck, Hanspeter Pfander, and József Deli
- Subjects
Terpene ,Hydrolysis ,Chemistry ,Mass spectrum ,General Medicine ,Nuclear chemistry ,Characterization (materials science) - Abstract
The acid-catalyzed hydrolysis of (3S,5R,6S,3′S,5′R)-5,6-epoxycapsanthin (5) led to (3S,5R,6R,3′S,5′R)-(7) and (3S,5R,6S,3′S,5′R)-capsokarpoxanthin (8). In addition, (3S,5R,8R,3′S,5′R)- (9), (3S,5R,8S,3′S,5′R)-capsochrome (10), and (3S,5R,6R,3′S,5′R)-3,6-epoxycapsanthin (6) afforded (3S,5S,6R,3′S,5′R)-capsokarpoxanthin (12) (3S,5S,8S,3′S,5′R)- (13) and (3S,5S,8R,3′S,5′S)-capsochrome (14) as well as (3S,5S,6R,3′S,5′R)-3,6-epoxyepicapsanthin (15). Compounds 5–15 were isolated in crystalline form and characterized by their UV/VIS, CD, 1H- and 13C-NMR, and mass spectra.
- Published
- 2010
- Full Text
- View/download PDF
39. ChemInform Abstract: Aesculaxanthin, a New Carotenoid Isolated from Pollens of Aesculus hippocastanum
- Author
-
Urs Niggli, Hanspeter Pfander, Zoltán Matus, Gyula Tóth, Andrea Steck, Péter Molnár, and József Deli
- Subjects
Aesculus hippocastanum ,chemistry.chemical_classification ,Chemistry ,Botany ,General Medicine ,Carotenoid - Published
- 2010
- Full Text
- View/download PDF
40. ChemInform Abstract: Partial Synthesis and Characterization of Karpoxanthins and Cucurbitaxanthin A Epimers
- Author
-
Péter Molnár, Andrea Steck, Zoltán Matus, Hanspeter Pfander, Gyula Tóth, and Jozsef Deli
- Subjects
Terpene ,Chemistry ,Organic chemistry ,Epimer ,General Medicine ,Characterization (materials science) - Published
- 2010
- Full Text
- View/download PDF
41. Complete assignment of 1H and 13C NMR data of pravastatin derivatives
- Author
-
Markus, Bacher, Karl, Baumann, Hermann, Knapp, Andrea, Steck, and Sigrid, Teibl
- Subjects
Carbon Isotopes ,Magnetic Resonance Spectroscopy ,Protons ,Pravastatin - Abstract
The complete (1)H and (13)C NMR data of 27 pravastatin derivatives are presented. Assignment was achieved by use of 1D and 2D NMR experiments (selective 1D NOE, COSY, NOESY, HSQC, HMBC).
- Published
- 2008
42. Synthesis of ether analogues derived from HUN-7293 and evaluation as inhibitors of VCAM-1 expression
- Author
-
Erwin P. Schreiner, Andrea Steck, Carolyn A. Foster, and Michael Kern
- Subjects
Depsipeptide ,chemistry.chemical_classification ,Tertiary amine ,Stereochemistry ,Organic Chemistry ,Clinical Biochemistry ,Pharmaceutical Science ,Vascular Cell Adhesion Molecule-1 ,Biological activity ,Ether ,Intercellular Adhesion Molecule-1 ,Biochemistry ,Chemical synthesis ,Peptides, Cyclic ,Cyclic peptide ,chemistry.chemical_compound ,Structure-Activity Relationship ,chemistry ,Amide ,Drug Discovery ,Side chain ,Molecular Medicine ,Humans ,Molecular Biology ,Ethers - Abstract
The cyclic depsipeptide HUN-7293 (1) and its D-lactate analogue 2 are highly potent inhibitors of inducible cell adhesion molecule expression. We report the synthesis of ether analogues varying in stereochemistry and side chain at the former hydroxyl acid position by employing a 'cut and paste chemistry' methodology starting from 1. As an additional fruit of this synthetic effort, a cyclodepsipeptide featuring a tertiary amine instead of a tertiary amide between PrLEU and MALA was obtained. Results on the inhibitory profile of these compounds in assays of VCAM-1 and ICAM-1 protein expression are discussed.
- Published
- 2004
43. Distribution of Carotenoids in Fruits and Vegetables as a Criterion for the Selection of Appropriate Chemopreventive Agents
- Author
-
Frederick Khachik, Zohar Nir, Rodney L. Ausich, Hanspeter Pfander, and Andrea Steck
- Subjects
chemistry.chemical_classification ,Lutein ,organic chemicals ,food and beverages ,Fatty acid ,macromolecular substances ,Orange (colour) ,biological factors ,Phytofluene ,Lycopene ,chemistry.chemical_compound ,Phytoene ,chemistry ,polycyclic compounds ,Food science ,Carotenoid ,Neurosporene - Abstract
Common fruits and vegetables contain approximately 40 to 50 carotenoids. Carotenoid-containing fruits and vegetables can be classified into three groups: greens, yellow/red, and yellow/orange. The carotenoids present in greens comprise carotenoid epoxides, lutein, α-carotene, and β-carotene. The yellow/red group contains mostly hydrocarbon carotenoids such as lycopene, neurosporene, y-carotene, ζ-carotene, a-carotene, β-carotene, phytofluene, and phytoene. Yellow/orange fruits and vegetables, in addition to the carotenoids in the other two categories, contain a complex mixture of carotenoids including carotenol fatty acid esters. The effect of various methods of food preparation on qualitative and quantitative distribution of carotenoids in common fruits and vegetables is described. An approach to selection of a mixture of carotenoids as chemopreventive agents based on absorption and relative abundance of these compounds in human serum is discussed.
- Published
- 1997
- Full Text
- View/download PDF
44. Bioavailability, Metabolism, and Possible Mechanism of Chemoprevention by Lutein and Lycopene in Humans
- Author
-
Hanspeter Pfander, Frederick Khachik, and Andrea Steck
- Subjects
chemistry.chemical_classification ,Lutein ,Antioxidant ,Chemistry ,medicine.medical_treatment ,food and beverages ,Metabolism ,Lycopene ,Bioavailability ,Zeaxanthin ,chemistry.chemical_compound ,Mechanism of action ,Biochemistry ,medicine ,medicine.symptom ,Carotenoid - Abstract
Lutein and lycopene are among the most abundant dietary carotenoids found in fruits, vegetables, and human serum. Human absorption and bioavailability studies involving lutein and its structural isomer zeaxanthin have established in vivo oxidation of these carotenoids to four metabolites. Lycopene apparently undergoes oxidation to yield lycopene-5,6-epoxide followed by cyclization and enzymatic reduction to form two dihydroxylycopenes with a novel five-member ring end-group. These dihydroxylycopenes, which have been identified as epimeric isomers of 2,6-cyclolycopene-1,5-diol, have been found in human serum. We present here our most recent data concerning the identity of 24 carotenoids, including eight of their metabolites in human serum. Possible metabolic transformations and the antioxidant mechanism of action for lutein and lycopene that lead to the formation of the oxidative metabolites of these two promising chemopreventive agents are described.
- Published
- 1997
- Full Text
- View/download PDF
45. Isolation of Capsanthone ((all-E,3R,5'R)-3-Hydroxy-β,κ-carotene-3',6'-dione) from Paprika (Capsicum annuum)
- Author
-
József Deli, Zoltán Matus, Péter Molnár, Gyuta Tóth, Andrea Steck, and Hanspeter Pfander
- Subjects
General Medicine ,General Chemistry - Abstract
From different species of paprika (Capsicum annuum) capsanthone (1) was isolated and characterized as (all-E,3R,5'R)-3-hydroxy-β,κ-carotene-3',6'-dione.
- Published
- 1995
- Full Text
- View/download PDF
46. Preparation and (E/Z)-Isomerization of the Diastereoisomers of Violaxanthin.
- Author
-
Péter Molnár, József Deli, Ferenc Zsila, Andrea Steck, Hanspeter Pfander, and Gyula Tóth
- Published
- 2004
47. Nigroxanthin (3',4'-Didehydro-β,γ-carotene-3,6'-diol), a New Carotenoid Isolated from Paprika (Capsicum annuum var. longum nigrum)
- Author
-
József Deli, Zoltán Matus, Péter Molnár, Gyula Tóth, Gábor Szalontai, Andrea Steck, and Hanspeter Pfander
- Subjects
General Medicine ,General Chemistry - Abstract
From red paprika (Capsicum annuum var. longum nigrum) nigroxanthin (1) was isolated as a minor carotenoid and, based on its spectral data, identified as (all-E)-3',4'-didehydro-β,γ-carotene-3,6'-diol.
- Published
- 1994
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.