Search

Saponins are natural surfactant compounds whose aqueous solutions can form stable foam and micellar solutions. Gypsophila arrostii Guss., Caryophyllaceae, represents the main source of saponins for industrial applications, such as vaccine adjuvants. Due to the complex and amphiphilic nature of triterpene saponins, these compounds require sophisticated techniques for their isolation and characterization. The hydromethanolic saponin fractions from the roots of the analyzed plant material were investigated by electrospray ionization ion trap multiple-stage mass spectrometry (ESI-IT-MS) in negative mode. According to the m/z values for the deprotonated molecule [M-H]− and the characteristic product ions, four known Gypsophila-type saponins were successfully characterized. In addition, four undescribed saponin compounds were detected by the registered ions [M-H]−.

Immunoadjuvants have major effects on the immune responses in vaccine formulations. Many specific adjuvants have been studied, including mineral salts, emulsions, cytokines, non-ionic block copolymers, carbohydrate polymers, muramyl dipeptides, and saponin-based adjuvants. Here, we focus on quillaic acid–containing saponin-based adjuvants and their mechanisms of action. Interestingly, when analyzing the adjuvants capable of forming immune-stimulating complexes, one of the characteristics shared by the majority of them is the presence of quillaic acid as the aglycone. This suggests that quillaic acid might be a strategic molecule for immunoadjuvant activity and a powerful candidate in the development of novel adjuvants.

Saponins are commonly found in higher plant parts, particularly in roots, tubers, leaves, and seeds, but N-triterpene saponins are rarely found in nature. Here, we focus on molecular structures and anticancer properties particularly in synergistic effects of toxicity, ion channel inhibitory, and opioid receptor modulatory effects of N-triterpene saponins.

Saporin, a type I ribosome-inactivating protein from soapwort plant, is a potent protein synthesis inhibitor. Catalytically, saporin is a characteristic N-glycosidase, and it depurinates a specific adenine residue from a universally conserved loop of the major ribosomal RNA (rRNA) of eukaryotic cells. It is well-known that saporin induces apoptosis through different pathways, including ribotoxic stress response, cell signal transduction, genomic DNA fragmentation and RNA abasic lyase (RAlyase) activity, and NAD+ depletion by poly-(ADP)-ribose polymerase hyperactivation. Saporin's high enzymatic activity, high stability, and resistance to conjugation procedures make it a well-suited tool for immunotherapy approaches.In the present study, we focus on saporin-based targeted toxins that may be efficacious therapeutic agents for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Our discussed points suggest that saporin may be a strategic molecule for therapeutic knockout treatments and a powerful candidate for novel drugs in the struggle against coronavirus 2019 (COVID-19).

Natural products from fungi, especially Ascomycota, play a major role in therapy and drug discovery. Fungal strains originating from marine habitats offer a new avenue for finding unusual molecular skeletons. Here, the marine-derived fungus Epicoccum nigrum (strain 749) was found to produce the azaphilonoid compounds acetosellin and 5′,6′-dihydroxyacetosellin. The latter is a new natural product. The biosynthesis of these polyketide-type compounds is intriguing, since two polyketide chains are assembled to the final product. Here we performed 13 C labeling studies on solid cultures to prove this hypothesis for acetosellin biosynthesis. © 2017 Georg Thieme Verlag KG Stuttgart. New York.

The maintenance of lipid and fatty acids unsaturated composition has been described as one of the mechanisms associated to drought tolerance, but research about the lipid profile in native plants of semiarid environment is still limited. The primary objective was to study whether lipid profiles correlates with drought resistance strategies (tolerant or avoidant) of two life forms (shrubs and grasses). The lipid classes and molecular species of green leaves of Larrea divaricata and Lycium chilense shrubs and Pappostipa speciosa and Poa ligularis grasses were determined using LC–ESI-MS/MS. The soil water content was very low during spring and leaf relative water content was between 47 and 74% in the four species. Lipid profiling was different between both life forms. The prevalent compounds were digalactosyldiacylglycerol (DGDG), monogalactosyldiacylglycerol (MGDG) and phosphatidic acid (PA). The lipid signature shows that L. divaricata adjust its lipid composition to tolerate drought, increasing the content of: a) total lipids and total phospholipids, b) structural phospholipids (36:4 and 36:2-PC, phosphatidylcholine; 36:4-PE, phosphatidylethanolamine), c) chloroplast and mitochondria lipids (32:1 and 32:0-PG, phosphatidylglycerol; 34:3, 36:6 and 36:3-DGDG), d) signaling lipids (34:3, 34:2 and 36:5-PA and PI, phosphatidylinositol), and e) polyunsaturated fatty acids (PUFAs, 18:3 and 18:2) and long chain polyunsaturated fatty acids (LC-PUFAs, in 40:2 and 42:2-PS, phosphatidylserine). This membrane lipid composition contributes to membrane stabilization as metabolic-functional strategy for drought tolerance in the Patagonian Monte. In addition, the 18:3 present in lipids of both grasses could be incorporated to lamb fed based on pastures and result healthy for human dietary. © 2019, National Institutes of Health: P20 RR16475 Kansas State University National Center for Research Resources PIP-CONICET191/2011 Kansas NSF EPSCoR: EPS-0236913 National Sleep Foundation: MCB 0455318, 0920663, DBI 0521587 PUE-IPEEC 044/2016, Lipid analysis was performed at the Kansas Lipidomics Research Center (KLRC). Instrument acquisition and method development at KLRC was supported by NSF grants MCB 0455318 and 0920663 and DBI 0521587 , and NSF EPSCoR grant EPS-0236913 with matching support from the State of Kansas through Kansas Technology Enterprise Corporation and Kansas State University . The KLRC is also supported by K-INBRE (NIH Grant P20 RR16475 from the INBRE program of the National Center for Research Resources). This research was funded by the National Research Council of Argentina ( PIP-CONICET191/2011 ), Instituto Patagónico para el Estudio de los Ecosistemas Continentales ( PUE-IPEEC 044/2016 ) and the Ministry of Science, Technology and Innovation of Chubut Province (Res. Nº 37/10 ). I thank to Fundación Patagonia Natural who allowed me to harvest plant material on his Wildlife Reserve “La Esperanza”.

Summary: Plants exposed to drought stress, as usually occurs in Patagonian shrublands, have developed different strategies to avoid or tolerate the lack of water during their development. Production of phenolic compounds (or polyphenols) is one of the strategies used by some native species of adverse environments to avoid the oxidative damage caused by drought. In the present study the relationship between phenolic compounds content, water availability and oxidative damage were evaluated in two native shrubs: Larrea divaricata (evergreen) and Lycium chilense (deciduous) of Patagonian shrublands by their means and/or by multivariate analysis. Samples of both species were collected during the 4 seasons for the term of 1 year. Soil water content, relative water content, total phenols, flavonoids, flavonols, tartaric acid esters, flavan-3-ols, proanthocyanidins, antioxidant capacity and lipid peroxidation were measured. According to statistical univariate analysis, L. divaricata showed high production of polyphenols along the year, with a phenolic compound synthesis enhanced during autumn (season of greatest drought), while L. chilense has lower production of these compounds without variation between seasons. The variation in total phenols along the seasons is proportional to the antioxidant capacity and inversely proportional to lipid peroxidation. Multivariate analysis showed that, regardless their mechanism to face drought (avoidance or tolerance), both shrubs are well adapted to semi-arid regions and the phenolic compounds production is a strategy used by these species living in extreme environments. The identification of polyphenol compounds showed that L. divaricata produces different types of flavonoids, particularly bond with sugars, while L. chilense produces high amount of non-flavonoids compounds. Synthesis: These results suggest that flavonoid production and accumulation could be a useful indicator of drought tolerance in native species. © 2016 Elsevier Masson SAS.

A new acylated and triterpenoidal saponin, named GS1, was isolated from the roots of Gypsophila arrostii Guss. On the basis of acid hydrolysis, comprehensive spectroscopic analyses and comparison with spectral data of known compounds, its structure was established as 3-O-β-D-xylopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→3)]-β-D-glucopyranosyl-{21-O-[(E)-3,4,5trimethoxycinnamoyl]}21-hydroxygypsogenin 28-O-β-D-glucopyranosyl-(1→2)- [β-D-arabinopyranosyl-(1→3)]-β-D-xylopyranosyl-(1→3]-α-L-rhamnopyranosyl ester. This article deals with the isolation and structural elucidation of new acylated and oleanane-type saponin.

WOS: 000454537500021, PubMed: 30600000, This is the first study on production of three dimensional chitinous microcages from ephippial eggs of a microcrustacean, Daphnia longispina (water flea) by keeping the original shape of its chitinous structure. Iron-based magnetic particles were successfully loaded into the chitinous microcages to enhance its heavy metal sorption capacity. The FT-IR, SEM-EDX and TGA analysis proved the purity of chitin and demonstrated that the loading of magnetic particles into the chitinous microcages was achieved. These newly obtained three-dimensional chitin microcages and magnetic particles loaded microcages were tested in Cd(II), Cr(III), Cu(II), Ni(II) and Zn(II) removal from aqueous solutions. Magnetic particles loaded microcages exhibited a better performance in removal of Cd(II), Cu(II) and Ni(II) ions; while unloaded microcages showed a higher affinity for Cr(III) and Zn(II). This study demonstrated that the chitin microcages are suitable carriers for iron-based magnetic particles. Here these new materials were studied only for removal of five heavy metal ions but these promising materials have a potential to be used in various fields., Selcuk University Research Foundation, Turkey [BAP-14201082], This study was funded by Selcuk University Research Foundation, Turkey"(project number: BAP-14201082).