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Marine natural products comprise unique chemical structures and vast varieties of biological activities. This review aims to summarize halichondrin, a marine natural product, and its synthetic analogs along with its therapeutic properties and mechanisms. Halichondrin and its analogs, derived from marine sponges, exhibit potent antineoplastic properties, making them promising candidates for cancer therapeutics. These compounds, characterized by their complex molecular structures, have demonstrated significant efficacy in inhibiting microtubule dynamics, leading to cell cycle arrest and apoptosis in various cancer cell lines. Several types of halichondrins such as halichondrins B, C, norhalichondrin B, and homohalichondrin B have been discovered with similar anticancer and antitumor characteristics. Since naturally available halichondrins show hurdles in synthesis, recent advancements in synthetic methodologies have enabled the development of several halichondrin analogs, such as E7389 (eribulin), which have shown improved therapeutic indices. Eribulin has shown excellent immunomodulatory properties by several mechanisms such as reprogramming tumor microenvironments, facilitating the infiltration and activation of immune cells, and inhibiting microtubule dynamics. Despite promising results, challenges remain in the synthesis and clinical application of these compounds. This review explores the mechanisms underlying the immunomodulatory activity of halichondrin and its analogs in cancer therapy, along with their clinical applications and potential for future drug development.

Six new polyketone metabolites, compounds (1-6) and seven known polyketone compounds (7-13) were isolated from Rhodiola tibetica endophytic fungus Alternaria sp. The structural elucidation of five new polyketone metabolites were elucidated on the basis of spectroscopic including 2D NMR and HRMS and spectrometric analysis. Inhibition rate evaluation revealed that compounds 1(EC 50  = 0.02 mM), 3(EC 50  = 0.3 mM), 6(EC 50  = 0.07 mM), 8(EC 50  = 0.1 mM) and 9(EC 50  = 0.04 mM) had inhibitory effect on the SARS-CoV-2 virus., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Rehmanniae Radix Praeparata is the processed products of the root of Rehmannia glutinosa. It has been used as a Traditional Chinese Medicine for thousands of years, and it has been found to possess widely pharmacological activities. In this study, three new 2,2'-difurylketone derivatives (rehmanniaeketone A-C) and two new chromones [3,8-dihydroxy-2-(2-hydroxyethyl)chromone and 3,8-dihydroxy-2-[(2-O-α-D-galactopyranosyloxy)ethyl]chromone] were isolated from the Rehmanniae Radix Praeparata. Furthermore all of the compounds were subjected to cytotoxic testing against the human lung carcinoma A549 cells. The cytotoxic results showed that rehmanniaeketone B and rehmanniaeketone C exhibited more stronger inhibition effects on the cell activity of A549 cells with the IC 50 5.23 μM and 2.05 μM than other compounds. And 3,8-dihydroxy-2-(2-hydroxyethyl)chromone exhibited moderately inhibitory activity with the IC 50 61 μM. Rehmanniaeketone A and 3,8-dihydroxy-2-[(2-O-α-D-galactopyranosyloxy]chromone showed no inhibitory effects., (© 2021 Wiley-VHCA AG, Zurich, Switzerland.)

In Portugal, maize has been used for centuries to produce an ethnic bread called broa , employing traditional maize varieties, which are preferred by the consumers in detriment of commercial hybrids. In order to evaluate the maize volatiles that can influence consumers' acceptance of broas , twelve broas were prepared from twelve maize varieties (eleven traditional and one commercial hybrid), following a traditional recipe. All maize flours and broas were analyzed by HS-SPME-GC-MS (headspace solid-phase microextraction) and broas were appraised by a consumer sensory panel. In addition, the major soluble phenolics and total carotenoids contents were quantitated in order to evaluate their influence as precursors or inhibitors of volatile compounds. Results showed that the major volatiles detected in maize flours and broas were aldehydes and alcohols, derived from lipid oxidation, and some ketones derived from carotenoids' oxidation. Both lipid and carotenoids' oxidation reactions appeared to be inhibited by soluble phenolics. In contrast, phenolic compounds appeared to increase browning reactions during bread making and, consequently, the production of pyranones. Traditional samples, especially those with higher contents in pyranones and lower contents in aldehydes, were preferred by the consumer sensory panel. These findings suggest that, without awareness, consumers prefer broas prepared from traditional maize flours with higher contents in health-promoting phenolic compounds, reinforcing the importance of preserving these valuable genetic resources.

Invasive species events related to globalization are increasing, resulting in parasitic outbreaks. Understanding of host defense mechanisms is needed to predict and mitigate against the consequences of parasite invasion. Using the honey bee Apis mellifera and the mite Varroa destructor, as a host-parasite model, we provide a comprehensive study of a mechanism of parasite detection that triggers a behavioral defense associated with social immunity. Six Varroa-parasitization-specific (VPS) compounds are identified that (1) trigger Varroa-sensitive hygiene (VSH, bees' key defense against Varroa sp.), (2) enable the selective recognition of a parasitized brood and (3) induce responses that mimic intrinsic VSH activity in bee colonies. We also show that individuals engaged in VSH exhibit a unique ability to discriminate VPS compounds from healthy brood signals. These findings enhance our understanding of a critical mechanism of host defense against parasites, and have the potential to apply the integration of pest management in the beekeeping sector.

Antimicrobial compounds from the natural source have gained greater relevance because of their wide spectrum of possible applications, especially in the aquaculture industry where pathogenic threat and antibacterial resistance are serious concerns. In this regard, Pseudomonas aeruginosa MBTDCMFRI Ps04 (P. aeruginosa Ps04) strain isolated from the tropical estuarine habitats of Cochin was evaluated for its antibacterial potential against major aquaculture pathogens. The physiological conditions for the maximum production of the active metabolite were also optimized. An activity-guided approach was employed further to isolate and characterize the secondary metabolite responsible for the inhibitory potential. It was found that the cell free supernatant (CFS) of P. aeruginosa Ps04 exhibited strong antibacterial activity against major aquaculture pathogens belonging to the genus Vibrio and Aeromonas and retained its potential even at 30% (v/v) dilution. The highest antibacterial activity was detected from 3rd day culture, grown in glycerol alanine media (1% each) as carbon and nitrogen source, respectively, at 30 °C, pH 7.0 and at a salinity of 20 parts per thousand (ppt). The activity of the antagonistic principle was found to be stable against variations in pH (pH 2-pH 12), temperature (up to 120 °C) and enzymatic treatments. Bioassay-guided purification followed by spectroscopic characterization of active fractions of P. aeruginosa Ps04 revealed that the compound 4-Hydroxy-11-methylpentacyclo [11.8.0.0 2,3 .0 11, 12 .0 16,17 ]henicosa-1,3,5,8(9),17-penten-14-one is responsible for its major antibacterial activity. The results of this study indicated that P. aeruginosa Ps04 has beneficial antibacterial properties which could be used in developing novel antimicrobial therapeutics against a variety of aquaculture pathogens.

The African weaver ant, Oecophylla longinoda , is used as a biological control agent for the management of pests. The ant has several exocrine glands in the abdomen, including Dufour's, poison, rectal, and sternal glands, which are associated with pheromone secretions for intra-specific communication. Previous studies have analyzed the gland secretions of Dufour's and poison glands. The chemistry of the rectal and sternal glands is unknown. We re-analyzed the secretions from Dufour's and poison glands plus the rectal and sternal glands to compare their chemistries and identify additional components. We used the solid-phase microextraction (SPME) technique to collect gland headspace volatiles and solvent extraction for the secretions. Coupled gas chromatography-mass spectrometry (GC-MS) analysis detected a total of 78 components, of which 62 were being reported for the first time. These additional components included 32 hydrocarbons, 12 carboxylic acids, 5 aldehydes, 3 alcohols, 2 ketones, 4 terpenes, 3 sterols, and 1 benzenoid. The chemistry of Dufour's and poison glands showed a strong overlap and was distinct from that of the rectal and sternal glands. The different gland mixtures may contribute to the different physiological and behavioral functions in this ant species.

Antimicrobial compounds from the safest source have gained greater relevance because of their wide spectrum of possible applications, especially in aquaculture industry, where pathogenic threat and antibacterial resistance are serious concerns. Bacillus stercoris MBTDCMFRI Ba37 isolated from mangrove environment of tropical estuarine habitats of Cochin exhibited a wide spectrum of antibacterial activity against major aquaculture pathogens belonging to genus Vibrio and Aeromonas. The structural characterization of the antibacterial compound from this strain may help in identifying their role as a biocontrol agent in aquaculture and allied sectors. The highest antibacterial activity was detected in 3rd day culture, grown in a modified Bacillus medium containing 1% of glycerol and 0.5% of glutamic acid at 30 °C, pH 8.0 and 15 ppt saline conditions. The inhibitory activity of the cell free supernatant was evident even at 20% v/v dilution. Preliminary studies on the nature of antibacterial action indicated that the bioactive principle is stable at temperatures up to 70 °C, between pH 6-9 and instable to lyzozyme and proteolytic enzymes. Bioassay guided purification followed by spectroscopic characterization of active fractions of B. stercoris MBTDCMFRI Ba37 revealed that the compound 1-(1-Hydroxyethyl)-1,7,10,12,13,15,17 heptamethyl-16-oxatetracyclo[8.7.0.0 2,3 .0 12,13 ]heptadecan-5-one, is responsible for its major antibacterial activity. This is the first report on isolation and characterization of an antibacterial compound from the species B. stercoris. The results of this study indicated that B. stercoris MBTDCMFRI Ba37 has beneficial antibacterial properties which could be useful in developing novel antimicrobial therapeutics against a variety of aquaculture and other pathogens.

Using antibiotics as feed additives have been successively banned worldwide from 1986; therefore, it is an urgent task to finding safe and effective alternatives. As natural products of plant origin, essential oils (EOs) are an outstanding option due to their reported bioactivity. In this research, ten EOs of Labiatae species were extracted by steam distillation and its chemical constituents were identified by gas chromatography-mass spectrometry (GC-MS). A total of 123 chemical compounds, including alkenes, phenols, aldehydes and ketones, were identified. The results of antioxidant activity carried out through DPPH free radical scavenging (DPPH) and ferric reducing antioxidant power (FRAP), showing that EOs of Ocimum basilicum Linn. (ObEO), Thymus mongolicus Ronn. (TmEO), Origanum vulgare Linn. (OvEO) and Mosla chinensis Maxim. (McEO) have strong antioxidant activities. Their 50%-inhibitory concentration (IC 50 ) value was <1.00, 1.42, 1.47 and 1.92 μg/mL, respectively; and their FRAP value was 1536.67 ± 24.22, 271.84 ± 4.93, 633.71 ± 13.14 and 480.66 ± 29.90, respectively. The results of filter paper diffusion showing that McEO, OvEO and TmEO inhibition zone diameter (IZD) are all over 30 mm. The results of two-fold dilution method showed that McEO, OvEO and TmEO have strong antibacterial activities against Staphylococcus aureus (S. aureus) and their minimal inhibitory concentrations (MIC) value was 1 μL/mL, 2 μL/mL, and 2 μL/mL, respectively. In conclusion, the results in this work demonstrate the possibility for development and application of EOs as potential feed additives.

The present study was aimed at analyzing the chemical components of the essential oil from six Pyrrosia species by GC/MS and evaluating their in vitro antibacterial activities. Seventy volatile compounds were identified in the essential oil of six Pyrrosia samples. The identified volatile components were divided into following nine categories: aldehydes, terpenoids, fatty acids, ketones, furans, hydrocarbons, alcohols, esters, and phenols. The major components of the essential oil were 2,4-pentadienal, phytol and nonanal. The antimicrobial assays showed that the essential oils from Pyrrosia samples exhibited a broad-spectrum antimicrobial activity. However, P. lingua had the highest antibacterial activity against Staphylococcus aureus (ATCC 25923) with a minimum inhibitory concentration (MIC) of 2.5 μL/mL. This article is the first report of the chemical components and antimicrobial activity of the essential oil from six Pyrrosia species, which will lay the foundation for developing medicinal resources from Pyrrosia fronds., (© 2020 Wiley-VHCA AG, Zurich, Switzerland.)

Eight new meroterpenoids (1-8) featuring β-triketone-conjugated terpenoids, rtomentones A-H, were isolated from the leaves of Rhodomyrtus tomentosa. Structures of the isolates were unambiguously established by a combination of NMR and ECD spectroscopy and X-ray diffraction analysis. Rtomentone C (3) was the first example of aromadendrane-based meroterpenoid containing an oxa-spiro[5.6] ring. Rtomentone D (4) was obtained as a racemic mixture confirmed by chiral HPLC analysis. The cytotoxicity against MDA-MB-231, A549, and DLD-1 cells of all isolates was evaluated., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The aim of this study was to evaluate the development of volatile compounds in yogurt samples obtained from goats fed a dietary supplementation with olive leaves (OL). For this purpose, thirty Saanen goats were divided into two homogeneous groups of 15 goats each: a control group that received a standard diet (CG) and an experimental group whose diet was supplemented with olive leaves (OLG). The trial lasted 28 days, at the end of which the milk of each group was collected and used for yogurt production. Immediately after production, and after 7 days of storage at 4 °C in the absence of light, the yogurt samples were characterized in terms of fatty acid profile, oxidative stability and volatile compounds by the solid-phase microextraction (SPME)-GC/MS technique. Dietary OL supplementation positively affected the fatty acid composition, inducing a significant increase in the relative proportion of unsaturated fatty acids, mainly oleic acid (C18:1 cis 9) and linolenic acid (C18:3). With regard to the volatile profile, both in fresh and yogurt samples stored for 7 days, the OL supplementation induced an increase in free fatty acids, probably due to an increase in lipolysis carried out by microbial and endogenous milk enzymes. Specifically, the largest variations were found for C6, C7, C8 and C10 free fatty acids. In the same samples, a significant decrease in aldehydes, mainly heptanal and nonanal, was also detected, supporting-at least in part-an improvement in the oxidative stability. Moreover, alcohols, esters and ketones appeared lower in OLG samples, while no significant variations were observed for lactones. These findings suggest the positive role of dietary OL supplementation in the production of goats' milk yogurt, with characteristics potentially indicative of an improvement in nutritional properties and flavor.

Background: Water absorption is the dominant factor affecting the quality deterioration of dried Lentinus edodes. We therefore analyzed the effect of moisture content and dynamic water status on physical properties of the mushroom stored at water activity (a w ), 0.33, 0.43, 0.67, 0.76, and 0.84 for 50 days. Moisture mobility and water status were analyzed using low-field nuclear magnetic resonance, while hardness and microstructure were determined as texture characteristics. Meanwhile, an electronic nose and headspace solid-phase micro-extraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS) were used to analyze the flavor properties of dried L. edodes., Results: The results showed that bound water was the dominant water status in dried L. edodes. The content and molecular mobility of bound water increased at a w = 0.67, 0.76, and 0.84. This contributed to discoloration, hardness loss, and microstructure sparsity of dried L. edodes. The increasing content and molecular mobility of bound water aggravated the deterioration of characteristic flavor by reducing acid, aldehyde, and ketone content., Conclusion: Unlike immobilized or free water, bound water had a critical influence on the quality deterioration of dried L. edodes during storage. © 2019 Society of Chemical Industry., (© 2019 Society of Chemical Industry.)

The formation of 3-methyl-2,4-nonanedione (MND) during red wine aging can contribute to the premature evolution of aroma, characterized by the loss of fresh fruit and development of dried fruit flavors. The identification of two new hydroxy ketones, 2-hydroxy-3-methylnonan-4-one (syn- and anti-ketol diastereoisomers) and 3-hydroxy-3-methyl-2,4-nonanedione (HMND), prompted the investigation of the precursors and pathways through which MND is produced and evolves. An HS-SPME-GC-MS method was optimized for their quantitation in numerous must and wine samples, providing insight into the evolution of MND, HMND, and ketols through alcoholic fermentation and wine aging. Alcoholic fermentation resulted in a significant decrease in MND and HMND and the simultaneous appearance of ketol diastereoisomers. The analysis of 167 dry red wines revealed significant increases in MND and anti-ketol contents through aging and a significant positive correlation between MND and anti-ketols. Additional experiments demonstrated that ketols are precursors to MND during red wine oxidation., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

This research analyzed the volatile composition of the fruits pulp of six prickly pear cultivars (NT, NE, NO, NA, FR, and ORI) growing in Spain, by headspace solid-phase microextraction and gas chromatography (GC-MS and GC-FID). A total of 35 compounds were isolated, identified, and quantified, with aldehydes, alcohols, and terpenes being the predominant chemical families, and esters, ketones, linear hydrocarbons, and terpenoids being also found. Nonanol, 2,6-nonadienal, 1-hexanol, 2-hexenal, and D-limonene were the predominant compounds. NT and FR cultivars showed the highest concentration of total volatile compounds. On the other hand, NE and NO cultivars presented the lowest concentration. Future studies on sensory evaluation are required to determine the sensory quality of the fruits of these Spanish cultivars., (© 2020 Institute of Food Technologists®.)

Marine natural products have proven, over the last half-century, to be effective biological modulators. These molecules have revealed new targets for cancer therapy as well as dissimilar modes of action within typical classes of drugs. In this scenario, innovation from marine-based pharmaceuticals has helped advance cancer chemotherapy in many aspects, as most of these are designated as first-in-class drugs. Here, by examining the path from discovery to development of clinically approved drugs of marine origin for cancer treatment-cytarabine (Cytosar-U®), trabectedin (Yondelis®), eribulin (Halaven®), brentuximab vedotin (Adcetris®), and plitidepsin (Aplidin®)- together with those in late clinical trial phases-lurbinectedin, plinabulin, marizomib, and plocabulin-the present review offers a critical analysis of the contributions given by these new compounds to cancer pharmacotherapy., (© 2019 The British Pharmacological Society.)

The changes of volatile compounds in soy sauce during long-term fermentation (12 months) were investigated using solid-phase microextraction (SPME) and stir bar sorptive extraction (SBSE). A total of 144 and 129 compounds were identified in soy sauce with long-term fermentation by SPME and SBSE, respectively. The contents of most compounds, such as acids, aldehydes, benzene and benzene derivatives, esters, lactones, pyrazines, pyrones, and pyrroles, showed a tendency to increase, whereas those of alcohols and ketones decreased according to long-term fermentation. In addition, principal component analysis and partial least squares discriminant analysis were applied to discriminate soy sauce samples according to fermentation periods and determine key volatile compounds related to long-term fermentation. The initial fermentation stages were mainly associated with some alcohols, ketones, and lactones, whereas the later stages were strongly associated with most esters, some phenols, benzene and benzene derivatives, and pyrroles. Moreover, the key volatile compounds associated with long-term fermentation in soy sauce samples were ethyl 3-methylbutanoate (ethyl isovalerate), ethyl pentanoate (ethyl valerate), 1-octen-3-yl acetate, 3-(methylthio)-1-propanol (methionol), ethyl benzoate, ethyl 2-phenylacetate, 1-(1H-pyrrol-2-yl)ethanone (2-acetylpyrrole), and 5-pentyl-2-oxolanone (γ-nonalactone). PRACTICAL APPLICATION: This study investigated changes of volatile compounds in soy sauce during long-term fermentation (12 months) using solid-phase microextraction and stir bar sorptive extraction. In addition, the key volatile compounds associated with long-term fermentation in soy sauce samples were determined. These results may help to predict the effective contributors related to long-term fermentation of soy sauce and improve the quality of soy sauce during long-term fermentation., (© 2019 Institute of Food Technologists®.)

A reliable Headspace-Solid Phase Microextraction (HS-SPME) method was developed for the determination of polar volatile components of commercial nut-based milk alternative drinks prior to Gas Chromatography-Mass Spectrometry (GC-MS) analysis. Under the optimum extraction conditions, a divinylbenzene (DVB)/Carboxen™ CAR)/polydimethylsiloxane (PDMS) fiber was used and 2 mL of sample was heated at 60 °C for 40 min under stirring, without salt addition. Ten compounds from different chemical classes (heptane, a-pinene, toluene, 2-methylpyrazine, 3-heptanone, heptanal, 2-octanone, 1-heptanol, benzaldehyde and 1-octanol) were chosen as model analytes for quantification. Limits of detection and limits of quantification were found to be 0.33-1.67 ng g -1 and 1-5 ng g -1 , accordingly. Good linearity, precision and accuracy were obtained as well as a wide linear range. The proposed method was successfully applied to various beverages including almond milk, walnut milk, peanut milk and almond chocolate milk. More than 70 volatile compounds were detected in the different samples. Most of the detected volatiles were aldehydes, ketones and alcohols. This technique can be used for the determination of volatile compounds in nut-based beverages, to detect compositional changes during storage and technological treatment used for their production.

In this study, a series of novel CD chiral stationary phases were fabricated by immobilization of mono-6 A -deoxy-N 3 -cyclodextrin onto silica surfaces followed by click regulation of CD primary face with 4-pentynoic acid (acidic moiety), 2-propynylamine (alkaline moiety) and L-propargylglycine (chiral amino acid moiety), respectively. Enantioseparations of various kinds of racemates including dansyl-amino acids, chiral lactides and diketones were conducted in reversed phase modes on these chiral stationary phases, where nearly forty diketones and chiral lactides were firstly separated on cyclodextrin stationary phases. 4-Pentynoic acid moiety can make the retention ability decline while amine moiety significantly enhanced the retention ability of the stationary phases. For most of the studied analytes, the chiral amino acid moiety had the most positive effects on both the retention time and the resolution. The inclusion complexation between chiral analytes and cyclodextrins were also investigated by fluorescence method., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Long-chain alkenones (LCAs) and alkenoates (LCEs) are highly valuable biomarkers for paleotemperature reconstructions. A major problem, however, for accurate quantification of these compounds using gas chromatography (GC) is co-elution with steryl ethers, wax esters, saturated ketones and other numerous mid-polarity compounds frequently encountered in marginal marine and lake sediments. Co-elution during GC separation is prevalent, particularly if the full homologous series of alkenones and alkenoates are to be analyzed. Taking advantage of the presence of two or more double bonds in LCAs and LCEs, the conventional silica gel impregnated with silver nitrate has previously been used to remove co-eluting compounds for LCAs. However, this conventional argentation chromatography is hampered by the extreme instability of silver nitrate, poor reproducibility, low recovery and short lifetime. Here we demonstrate a highly efficient flash chromatographic approach based on silver thiolate chromatographic material (AgTCM) that overcomes the shortcomings of the traditional argentation chromatography and allows repeated sample preparation (up to 62 samples in one test) with little loss in separation efficiency. AgTCM selectively extracts LCAs and LCEs and effectively eliminates co-eluting compounds including steryl ethers and wax esters for the subsequent gas chromatography (GC) analysis. This new method, therefore, allows low-cost and high-throughput sample preparation for comprehensive quantification of the full homologous series of LCAs and LCEs in marine and lake sediments., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Biopolymers used for food contact materials must be evaluated in order to ensure food safety and quality. In this work, the aroma profile of starch-based packaging materials, presented as pellets and films has been characterized. Headspace solid phase microextraction (HS-SPME) technique and gas chromatography coupled to both mass spectrometry and a sniffing port (GC-MS-O) were used for identification. In total, 35 odorant compounds were detected. The results showed that aldehydes were the odorants with the highest aromatic impact in starch-based films. Eight odorant compounds, such as trimethylamine, 1-octen-3-one, sotolon, (Z) and (E)-2-nonenal, p-vinylguaiacol, eugenol and 1-undecanol, defined as aroma-impact compounds, obtained modified frequency values (MF%) above 60% in at least 3 out of 4 films. A sensory panel evaluated the toasted, sweet/fruity, green, flower, distasteful, fat and spices notes in the films and it was observed that the quality of all samples decreased when the toasted and spices notes increased., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The aim of this review is to describe the volatile aroma compounds of green coffee beans and evaluate sources of variation in the formation and development of coffee aroma through postharvest processing. The findings of this survey showed that the volatile constituents of green coffee beans (e.g., alcohols, aldehydes, and alkanes) have no significant influence on the final coffee aroma composition, as only a few such compounds remain in the beans after roasting. On the other hand, microbial-derived, odor-active compounds produced during removal of the fruit mucilage layer, including esters, higher alcohols, aldehydes, and ketones, can be detected in the final coffee product. Many postharvest processing including drying and storage processes could influence the levels of coffee aroma compositions, which remain to be elucidated. Better understanding of the effect of these processes on coffee aroma composition would assist coffee producers in the optimal selection of postharvest parameters that favor the consistent production of flavorful coffee beans., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The methanol extract of the flowers of the Australian eucalypt tree Corymbia torelliana yielded six new β-triketone-flavanone hybrids, torellianones A-F (1-6), the tetrahydroxycyclohexane torellianol A (7), and known β-triketones (4 S)-ficifolidione (8) and (4 R)-ficifolidione (9), and β-triketone-flavanones kunzeanone A (10) and kunzeanone B (11). Torellianones A and B, C and D, and E and F were each isolated as inseparable diastereomeric mixtures. Exchange correlations observed in a ROESY spectrum indicated that 5 and 6 also interconverted between stable conformers. The structures of 1-7 were elucidated from the analysis of 1D/2D NMR and MS data. Relative configurations of torellianones C-F and torrellianol A were determined from analysis of ROESY data. Compounds 1-10 were tested for antiplasmodial activity against a drug-sensitive (3D7) strain of Plasmodium falciparum, with 3-6 and 8-10 showing limited antiplasmodial activity, with IC 50 values ranging from 3.2 to 16.6 μM.

Callistrilones F - K (1 - 6), six new triketone-phloroglucinol-monoterpene hybrids were isolated from the twigs and leaves of Callistemon rigidus. Their structures with absolute configurations were established by a combination analysis of NMR spectra, X-ray diffraction, and electronic circular dichroism (ECD) calculations. Compounds 3 and 4 exhibited moderate inhibitory activities against herpes simplex virus (HSV-1) with IC 50 values of 10.00 ± 2.50 and 12.50 ± 1.30 μm, respectively., (© 2018 Wiley-VHCA AG, Zurich, Switzerland.)

Sol-gel urea functionalized-[bis(hydroxyethyl)amine] terminated polydimethylsiloxane coating was developed for capillary microextraction-high performance liquid chromatographic analysis from aqueous samples. A fused silica capillary is coated from the inside with surface bonded coating material and is created through in-situ sol-gel reaction. The urea-functionalized coating was immobilized to the inner surface of the capillary by the condensation reaction of silanol groups of capillary and sol-solution. The characterization of the coating material was successfully done by using X-ray photoelectron spectroscopy, thermogravimetric analysis, field emission scanning electron microscope, and energy dispersive X-ray spectrometer. To make a setup of online capillary microextraction-high performance liquid chromatography, the urea functionalized capillary was installed in the HPLC manual injection port. The analytes of interest were pre-concentrated in the coated sampling loop, desorbed by the mobile phase, chromatographically separated on C-18 column, and analyzed by UV detector. Sol-gel coated capillaries were used for online extraction and high-performance liquid chromatographic analysis of phenols, ketones, aldehydes, and polyaromatic hydrocarbons. This newly developed coating showed excellent extraction for a variety of analytes ranging from highly polar to non-polar in nature. The analysis using sol-gel coating showed excellent overall sensitivity in terms of lower detection limits (S/N = 3) for the analytes (0.10 ng mL -1 -14.29 ng mL -1 ) with acceptable reproducibility that is less than 12.0%RSD (n = 3). Moreover, the capillary to capillary reproducibility of the analysis was also tested by changing the capillary of the same size. This provided excellent%RSD of less than 10.0% (n = 3)., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Milled Roselle ( Hibiscus sabdariffa L.) seeds of the UMKL cultivar were analyzed for proximate composition, water and oil absorption capacity, and the influence of storage conditions on storage stability. The storage stability was determined under four types of conditions: light/oxygen (air) (LO), light/nitrogen (LN), darkness/oxygen (air) (DO), and darkness/nitrogen (DN) while monitoring for seven consecutive months. During the storage period, the formation of volatiles was determined using dynamic headspace sampling and Gas Chromatography-Mass Spectrometry (GC-MS) analysis. In total, 85 volatiles were identified, mainly aldehydes, alcohols, ketones, furans, and acids indicating lipid oxidation. It is recommended that milled Roselle seeds should be flushed with nitrogen and stored in darkness. Under these conditions, the seeds can be stored for at least three months without changes in volatile profile. This is important to ensure the good quality of milled Roselle seeds for further commercialization., Competing Interests: The authors declare no conflict of interest. The founding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.

Bradysia procera is a serious insect pest of Panax ginseng plants. This study was conducted to determine the toxicity and mechanism of action of three phenylpropanoids, three terpenoids, and a ketone from Syzygium aromaticum bud methanol extract and hydrodistillate against third-instar larvae and eggs of B. procera. In a filter-paper mortality bioassay, methyl salicylate (LC 50 , 5.26μg/cm 2 ) was the most toxic compound, followed by 2-nonanone, eugenol, and eugenyl acetate (8.77-15.40μg/cm 2 ). These compounds were significantly less toxic than either thiamethoxam, clothianidin, or cypermethrin. Egg hatching was inhibited by 97, 85, and 40% at 11.7μg/cm 2 of methyl salicylate, 2-nonanone, and eugenol, respectively. The egg-hatching inhibition of these insecticides was between 90 and 94% at 0.09μg/cm 2 . These constituents were consistently more toxic in closed versus open containers, indicating that toxicity was achieved mainly through the action of vapor. The mechanism of larvicidal action of methyl salicylate, eugenol, and eugenyl acetate might be primarily due to interference with the octopaminergic system. 2-Heptyl acetate and 2-nonanone might act on both acetylcholinesterase and the octopaminergic receptor. 2-Heptanone might act primarily on acetylcholinesterase. Further studies will warrant possible applications of S. aromaticum bud-derived products as potential larvicides and ovicides for the control of B. procera., (Copyright © 2018. Published by Elsevier Inc.)

Natural amino acids are well known to form coordination polymers with transition metal ions. In this study, six homochiral metal-organic frameworks constructed from Zn 2+ or Co 2+ ions and various enantiopure amino acid (L-tyrosine, L-histidine, L-tryptophan and L-glutamic acid), namely [Zn(L-tyr)] n (L-tyrZn), [Zn 4 (btc) 2 (Hbtc)(L-His) 2 (H 2 O) 4 ]·1.5H 2 O, {[Zn 2 (L-trp) 2 (bpe) 2 (H 2 O) 2 ]·2H 2 O·2NO 3 } n , [Co 2 (L-Trp)(INT) 2 (H 2 O) 2 (ClO 4 )], [Co 2 (sdba)((L-Trp) 2 ] and [Co(L-Glu)(H 2 O)·H 2 O] ∞ , were synthesized according to the methods previously reported in the literature. The six homochiral MOFs were explored as the chiral stationary phases for high-performance liquid chromatographic separation of enantiomers using hexane/isopropanol or hexane/dichloromethane as mobile phase. Various types of enantiomers such as alcohols, amines, ketones, ethers, organic acids, etc. can be resolved on these homochiral MOF columns. The results revealed that the enantioseletivities of homochiral MOFs based on amino acids as chiral bridging ligands used as stationary phases are practical in HPLC., (© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The aim of this study examined the characterization of extra virgin olive oil samples from the main cultivar Chemlali, grown in five olive orchards with different soil type (Sandy, Clay, Stony, Brown, Limestone and Gypsum). Volatile compounds were studied using headspace-solid phase micro-extraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) technics. Moreover, the sterol profile was established using gas chromatography-mass spectrometry. 35 different volatile compounds were identified: alcohols, esters, aldehydes, ketones and hydrocarbons. The chemical composition of the volatile fraction was characterized by the preeminence of 2-hexenal (32.75%) and 1-hexanol (31.88%). Three sterols were identified and characterized. For all olive oil samples, ß-sitosterol (302.25 mg/kg) was the most abundant sterol. Interestingly, our results showed significant qualitative and quantitative differences in the levels of the volatile compounds and sterols from oils obtained from olive trees grown in different soil type.

This study aimed to examine the anti-candidal efficacy of a novel ketone derivative isolated from Diaporthe sp. ED2, an endophytic fungus residing in medicinal herb Orthosiphon stamieus Benth. The ethyl acetate extract of the fungal culture was separated by open column and reverse phase high-performance liquid chromatography (HPLC). The eluent at retention time 5.64 min in the HPLC system was the only compound that exhibited anti-candidal activity on Kirby-Bauer assay. The structure of the compound was also elucidated by nuclear magnetic resonance and spectroscopy techniques. The purified anti-candidal compound was obtainedas a colorless solid and characterized as 3-hydroxy-5-methoxyhex-5-ene-2,4-dione. On broth microdilution assay, the compound also exhibited fungicidal activity on a clinical strain of Candida albicans at a minimal inhibitory concentration of 3.1 μg/ml. The killing kinetic analysis also revealed that the compound was fungicidal against C. albicans in a concentration- and time-dependent manner. The compound was heat-stable up to 70°C, but its anti-candidal activity was affected at pH 2.

Two pairs of rare naturally occurring racemic lipids, (±)-4,7-dihydroxy-4-methyl-2,5-heptanedione (1), and (±)-7-butoxy-4-hydroxy-4-methyl-2,5-heptanedione (2) were isolated from the red alga Chondria crassicaulis Harv. The structures of the racemic mixtures of 1 and 2 were elucidated by detailed spectroscopic techniques, including 1D and 2D NMR ( 1 H and 13 C NMR, 1 H- 1 H COSY, HSQC, and HMBC) as well as mass spectrometry and optical rotation experiments, and by comparison with data for related known analogs. This is the first report of naturally occurring 4-hydroxy-4-methyl-2,5-heptanedione derivatives. Antifungal, PTP1B inhibitory, and receptor tyrosine kinase inhibitory activities of these two compounds were investigated. The results showed that compounds 1 and 2 exhibited good selective inhibition against RET tyrosine kinase activity with IC 50 values of 9.56 and 8.93 μM, respectively. Compound 1 also displayed moderate antifungal activity against Cryptococcus neoformans (32609), showing a MIC 80 value of 32 μg/ml.

Chemical investigations of the MeOH extract of air dried flowers of the Australian tree Angophora woodsiana (Myrtaceae) yielded two new β-triketones, woodsianones A and B (1, 2) and nine known β-triketones (3-11). Woodsianone A is a β-triketone-sesquiterpene adduct and woodsianone B is a β-triketone epoxide derivative. The structures of the new and known compounds were elucidated from the analysis of 1D/2D NMR and MS data. The relative configurations of the compounds were determined from analysis of 1 H- 1 H coupling constants and ROESY correlations. All compounds (1-11) had antiplasmodial activity against the chloroquine sensitive strain 3D7. The known compound rhodomyrtone (5) and new compound woodsianone B (2) showed moderate antiplasmodial activities against the 3D7 strain (1.84µM and 3.00µM, respectively) and chloroquine resistant strain Dd2 (4.00µM and 2.53µM, respectively)., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Three new isoaigialones, A, B, and C (1-3), along with aigialone (4), were isolated from the crude EtOAc extract of a Phaeoacremonium sp., an endophytic fungus obtained from the leaves of Senna spectabilis. The structures of these compounds were elucidated based on the analysis of spectroscopic data. Compounds 2 and 4 were active against the phytopathogenic fungi Cladosporium cladosporioides and C. sphaerospermum. This is the first report of metabolites produced by an Phaeoacremonium sp., associated with S. spectabilis.

This study investigated the composition of volatile compounds in two pummelo cultivars, including 'Shatian' and 'Guanxi', cultivated in different regions of China with the aim of studying the effect of cultivar and cultivation condition on biosynthesis of volatile compounds in pummelo. Volatile compounds were extracted from pummelo juice using head-space microextraction and then analyzed using gas chromatography coupled with mass spectrometry. Results showed that a total of 49 volatile compounds was detected in the study, including 11 aldehydes, 7 alcohols, 3 ketones, 7 esters, 19 terpenes and 2 other volatiles. The 'Guanxi' pummelo cultivar possessed a more complex composition of volatile compounds compared with the 'Shatian' cultivar. Meanwhile, the volatile compounds appeared to exhibit a higher concentration in the 'Guanxi' cultivar samples than the 'Shatian' cultivar. Cluster analysis revealed that the 'Guanxi' cultivar samples from the different regions were grouped together, whereas the 'Shatian' cultivar samples were assembled. Principal component analysis showed that an obvious separation was observed between the 'Guanxi' and 'Shatian' cultivar. However, the 'Shatian-SC15' was significantly separated from the other 'Shatian' cultivar samples. These indicated that cultivar genotype was the primary factor that determined the volatile profile of the pummelo cultivar. Cultivation region might affect the biosynthesis of volatile compounds, resulting in the differentiation of the volatile composition in each pummelo cultivar.

Three novel 2,3-diaryl indone derivatives, ascomindones A-C (1-3), and two new isobenzofuran derivatives, ascomfurans A (4) and B (5), together with four know compounds (6-9) were isolated from the culture of a mangrove-derived fungus Ascomycota sp. SK2YWS-L. Their structures were elucidated on the interpretation of spectroscopic data. 1 and 4 were further constructed by analysis of X-ray diffraction. Antioxidant properties based on 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl radical scavenging activities and the ferric reducing ability power (FRAP) of the new compounds were assayed. All of them exhibited significant effects, of which 1 showed more potent activity than ascorbic acid in scavenging DPPH radical with IC 50 value of 18.1 μM.

Nitrogen (N) is an important macronutrient for plant growth and development, but the regulatory mechanism of volatile compounds in response to N deficiency is not well understood, especially in cucumber, which consumes excessive N during growth. In this study, the major volatile compounds from cucumber leaves subjected to N deficiency were analyzed by GC-MS. A total of 24 volatile components were identified including 15 aldehydes, two ketones, two alkenes, and five other volatile compounds in 9930 leaves. Principal component analysis using volatile compounds from cucumber leaves provided good separation between N-sufficient and N-deficient treatments. The main volatiles in cucumber leaves were found to be C6 and C9 aldehydes, especially ( E )-2-hexanal and ( E , Z )-2,6-nonadienal. ( E )-2-hexanal belonged to the C6 aldehyde and was the most abundant compound, whereas ( E , Z )-2,6-nonadienal was the chief component of C9 aldehydes. During N-deficient treatment, short-chain volatile content was significantly improved at 5 day, other volatiles displayed significant reduction or no significantly changes in all sampling points. Improvement of short-chain volatiles was confirmed in the six other inbred lines at 5 day after N-deficient treatments. The expression analysis of 12 cucumber LOX genes and two HPL genes revealed that CsLOX19 , CsLOX20 , and CsLOX22 had common up-regulated expression patterns in response to N-deficient stress in most inbred lines; meanwhile, most sample points of CsHPL1 also had significant up-regulated expression patterns. This research focused on the relationship between volatiles in cucumber and different nitrogen environments to provide valuable insight into the effect of cultivation and management of the quality of cucumber and contributes to further research on volatile metabolism in cucumber., Competing Interests: The authors declare no conflict of interest.

Asparagus suaveolens is a medicinal plant used in Lesotho and South Africa to treat epilepsy and gonorrhea. The current investigation identifies the compound responsible for the antiepileptic and antimicrobial properties as palmitone which showed antigonorrhea activities against WHO 2008 Neisseria gonorrhea F and 0 strains more than the standard used, gentamicin. These results support the traditional use of A. suaveolens for treatment of gonorrhea and epilepsy since palmitone is known as an anticonvulsant agent. This is the first study indicating the presence of palmitone in the Asparagus genus and demonstrates the in vitro antigonorrhea activity of palmitone.

In this work, we present the in vitro schistosomicidal activity evaluation of the most active dichloromethane fraction (FDm) (ED50=83.5μg/mL) and of a mixture of the major alkaloids ((-)-cassine/(-)-spectaline, C/E) (ED50=37.4μg/mL) from the flowers of Senna spectabilis against adult worms and cercariae. We also demonstrate other toxic effects including paralysis of the adult worms, inhibition of the secretory activity, tegument lesions and cercaricidal activity. In the association test of Praziquantel (PZQ)-C/E, we observed up to 80% mortality of Schistosoma mansoni in comparison to PZQ monotherapy. Due to the diversity of the toxic effects, the schistosomicidal activity of C/E is likely a result of a multitarget mechanism involving the tegument, secretory system and neuromotor action., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The present study was designed to identify the chemical constituents of the methanolic extract of Curcuma longa L. rhizomes and their inhibitory effect on a hepatoma cell line. The methanolic extract was subjected to GC-MS analysis to identify the volatile constituents and the other part of the same extract was subjected to liquid column chromatographic separation to isolate curcumin. The inhibition of cell growth in the hepatoma cell line and the cytopathological changes were studied. GC-MS analysis showed the presence of fifty compounds in the methanolic extract of C. longa. The major compounds were ar-turmerone (20.50 %), β-sesquiphellandrene (5.20 %) and curcumenol (5.11 %). Curcumin was identified using IR, 1H and 13C NMR. The inhibition of cell growth by curcumin (IC50 = 41.69 ± 2.87 μg mL-1) was much more effective than that of methanolic extract (IC50 = 196.12 ± 5.25 μg mL-1). Degenerative and apoptotic changes were more evident in curcumin- treated hepatoma cells than in those treated with the methanol extract. Antitumor potential of the methanolic extract may be attributed to the presence of sesquiterpenes and phenolic constituents including curcumin (0.051 %, 511.39 μg g-1 dried methanol extract) in C. longa rhizomes.

A curcuminoids, benzalacetone-, and quinolone-producing type III polyketide synthase (HsPKS3) from Huperzia serrata uniquely catalyzes the formation of unnatural 2-substituted quinolones and 1,3-diketones via head-to-head condensation of two completely different substrates. The broad range of substrate tolerance of HsPKS3 facilitates accessing structurally diverse 2-substituted quinolones and 1,3-diketones.

The stereoselective synthesis of chiral 1,3-diols with the aid of biocatalysts is an attractive tool in organic chemistry. Besides the reduction of diketones, an alternative approach consists of the stereoselective reduction of β-hydroxy ketones (aldols). Thus, we screened for an alcohol dehydrogenase (ADH) that would selectively reduce a β-hydroxy-β-trifluoromethyl ketone. One potential starting material for this process is readily available by aldol addition of acetone to 2,2,2-trifluoroacetophenone. Over 200 strains were screened, and only a few yeast strains showed stereoselective reduction activities. The enzyme responsible for the reduction of the β-hydroxy-β-trifluoromethyl ketone was identified after purification and subsequent MALDI-TOF mass spectrometric analysis. As a result, a new NADP(+) -dependent ADH from Pichia pastoris (PPADH) was identified and confirmed to be capable of stereospecific and diastereoselective reduction of the β-hydroxy-β-trifluoromethyl ketone to its corresponding 1,3-diol. The gene encoding PPADH was cloned and heterologously expressed in Escherichia coli BL21(DE3). To determine the influence of an N- or C-terminal His-tag fusion, three different recombinant plasmids were constructed. Interestingly, the variant with the N-terminal His-tag showed the highest activity; consequently, this variant was purified and characterized. Kinetic parameters and the dependency of activity on pH and temperature were determined. PPADH shows a substrate preference for the reduction of linear and branched aliphatic aldehydes. Surprisingly, the enzyme shows no comparable activity towards ketones other than the β-hydroxy-β-trifluoromethyl ketone., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

An 8-zone simulated moving bed chromatography with internal recycle (8ZSMB-IR) has been designed for center-cut separation, that is, for isolating an intermediately adsorbed component out of a multicomponent mixture. The system consists of two integrated subunits and operates in a fully continuous manner. In the first subunit the feed mixture is split into two fractions containing either a single component or a binary mixture. The binary mixture is recycled through the internal raffinate or extract port into the second subunit, where the target product is isolated. Additionally, the solvent is also recycled internally. For a case study, the separation of a ternary mixture of cycloketones as a model system under weakly non-linear isotherm conditions has been investigated. A few novel configurations of the 8ZSMB-IR unit including the arrangement of the internal recycle of extract, raffinate and solvent streams between two subunits have been examined with respect to various performance indicators for the process realization. The unit performed best with the developed configuration when the internal raffinate stream was recycled and the solvent recycling loop was closed between the last and the first zone of the first subunit. That configuration has further been analyzed experimentally and numerically. On the basis of the results a strategy for determining reliable operating conditions for the 8ZSMB-IR process has been developed. The procedure exploited a model of the process dynamics, which was implemented to refine the isotherm coefficients and to quantify the mixing effect of the liquid stream inside the recycling loops. The upgraded model with the adjusted parameters has been validated based on experimental data and successfully applied for optimizing the operating conditions of the separation., (Copyright © 2016 Elsevier B.V. All rights reserved.)

In a previous study, two highly potent yet unidentified odorants were detected that were present at trace levels in the volatile fraction of Boswellia sacra gum resin. These two compounds were isolated semipreparatively from the volatile oil by a sensory-guided fractionation process involving microscale bulb-to-bulb distillation, countercurrent chromatography, and preparative gas chromatography. In this manner, the two oxygenated sesquiterpenes could be identified as rotundone (1) and mustakone (2). Compound 2 is described for the first time as a potent odorant with a very low odor threshold.

The sub-dermal secretory cavities (glands) embedded within the leaves of Eucalyptus (Myrtaceae) were once thought to be the exclusive repositories of monoterpene and sesquiterpene oils. Recent research has debunked this theory and shown that abundant non-volatile compounds also occur within foliar glands. In particular, glands of four species in subgenus Eucalyptus contain the biologically active flavanone pinocembrin. Pinocembrin shows great promise as a pharmaceutical and is predominantly plant-sourced, so Eucalyptus could be a potential commercial source of such compounds. To explore this we quantified and assessed the purity of pinocembrin in glands of 11 species of E. subg. Eucalyptus using Electro-Spray Ionisation Liquid Chromatography Mass Spectrometry of acetonitrile extracts and Gas Chromatography Mass Spectrometry analyses of hexane extracts of isolated glands which were free from other leaf tissues. Our results showed that the glands of subgenus Eucalyptus contain numerous flavanones that are structurally related to pinocembrin and often present in much greater abundance. The maximum concentration of pinocembrin was 2 mg g-1 dry leaf found in E. stellulata, whereas that of dimethylpinocembrin (5,7-dimethoxyflavanone) was 10 mg g-1 in E. oreades and that of pinostrobin (5-hydroxy-7-methoxyflavanone) was 12 mg g-1 in E. nitida. We also found that the flavanones are exclusively located within the foliar glands rather than distributed throughout leaf tissues. The flavanones differ from the non-methylated pinocembrin in the degree and positions of methylation. This finding is particularly important given the attractiveness of methylated flavonoids as pharmaceuticals and therapeutics. Another important finding was that glands of some members of the subgenus also contain flavanone O-glucosides and flavanone-β-triketone conjugates. In addition, glands contain free β-triketones, β-triketone heterodimers and chromone C-glucosides. Therefore, the foliar glands of this taxonomically distinct group of plants are a rich source of a range of flavonoids and other biologically active compounds with great commercial potential.

Normal phase chiral HPLC and SFC methods are presented for the enantiomeric separation of 21 α-aryl ketones with a unique class of chiral stationary phases (CSPs) based on cyclofructans (CFs). Separations were achieved for all but 2 analytes, with 17 compounds attaining baseline separation having resolution values up to 4.0. Most separations obtained in HPLC could be transferred to SFC, but the HPLC resolutions were generally better due to greater enantiomeric selectivity values. A structure-separation relationship (SSR) was developed to identify important structural features for separation of this class of compounds using CF-based CSPs. Preliminary studies are also presented that demonstrate the utility of the CF CSPs to investigate the base-induced enantiomerization of α-aryl ketones. It was demonstrated that even small amounts of base (0.01%v/v) in the mobile phase results in rapid, on-column, enantiomerization. Lastly, CSPs composed of superficially porous particles were used to achieve comparable separations of this class of chiral compounds, but at a fraction of the analysis time compared to CSPs composed of fully porous particles., (Copyright © 2015 Elsevier B.V. All rights reserved.)

The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Yponomeutidae) is the most serious pest of cruciferous crops grown in the world causing economic yield loss. Several synthetic insecticides have been used against P. xylostella but satisfactory control was not achieved due to development of resistance to insecticides. Therefore, the present study was carried out to screen different fractions of Zanthoxylum armatum for their insecticidal activities against second instar larvae of P. xylostella. Results indicate, all the fractions showed activity to P. xylostella. However, n-hexane fraction of Z. armatum showed maximum larvicidal activity with minimum LC50 value of 2988.6 ppm followed by ethanol (LC50 = 12779.7 ppm) and methanol fraction (LC50 = 12908.8 ppm) whereas chloroform fraction was least toxic (LC50 = 16750.6 ppm). The GC-MS analysis of n-hexane fraction of leaf extract showed maximum larvicidal activity, which may be due to two major compounds i.e. 2-undecanone (19.75%) and 2-tridecanone (11.76%).

In search of effective antidiabetic agents having therapeutic effect by inhibiting α-glucosidase and preventive effect by scavenging free radicals, Horsfieldia macrobotrys showed promising bioactivity required for the proposed criteria. Bioassay-guided isolation of the stem bark extract resulted in two new arylalkanones named horsfieldone A (1) and maingayone D (2), together with a new flavanone C-glucoside named 8-C-β-d-glucopyranosylpinocembrin (3). Their structures and stereochemistry were determined by spectroscopic techniques as well as Mosher's method. Of isolated compounds, maingayone D (2) was the most potent inhibitors against both α-glucosidases and free radicals. The presence of additional phenolic moieties in 2 clearly indicated their critical roles in inhibitory effects. Further investigation on mechanism underlying α-glucosidase inhibition indicated that maingayone D (2) could retard the enzyme function by both competitive and noncompetitive manners., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Fast gas chromatography-surface acoustic wave sensor (GC/SAW) has been applied for the detection of the pharmacological volatiles emanated from Houttuynia cordata Thunb which is from South Korea. H. cordata Thunb with unpleasant and fishy odors shows a variety of pharmacological activities such as anti-microbial, anti-inflammatory, anti-cancer, and insect repellent. The aim of this study is to show a novel quality control by GC/SAW methodology for the discrimination of the three different parts of the plant such as leaves, aerial stems, and underground stems for H. cordata Thunb. Sixteen compounds were identified. β-Myrcene, cis-ocimene and decanal are the dominant volatiles for leaves (71.0%) and aerial stems (50.1%). While, monoterpenes (74.6%) are the dominant volatiles for underground stems. 2-Undecanone (1.3%) and lauraldehyde (3.5%) were found to be the characteristic components for leaves. Each part of the plant has its own characteristic fragrance pattern owing to its individual chemical compositions. Moreover, its individual characteristic fragrance patterns are conducive to discrimination of the three different parts of the plant. Consequently, fast GC/SAW can be a useful analytical method for quality control of the different parts of the plant with pharmacological volatiles as it provides second unit analysis, a simple and fragrant pattern recognition.

Gas-diffusion microextraction (GDME) was applied to the extraction of vicinal diketones in bread samples aimed at the determination of these compounds by high-performance liquid chromatography with ultraviolet detection (HPLC-UV). For the first time, GDME was used for direct chemical determination in solid samples, i.e. avoiding any sample preparation prior to extraction. Different extraction parameters were studied and optimized, namely temperature, time and chemical composition of the acceptor solution where o-phenylenediamine was used as a derivatizing agent, originating quinoxalines that could be determined at 315 nm. GDME demonstrated to be a good tool for the sampling of volatile compounds in solid samples with suitable method features for butane-2,3-dione (diacetyl, DC), pentane-2,3-dione (PN) and hexane-2,3-dione (HX): low LODs (6.0, 8.6 and 12 μg kg(-1), for DC, PN and HX respectively) and LOQs (20, 29 and 38 μg kg(-1), for DC, PN and HX respectively), r(2) above 0.990, and CV around 5%. The developed methodology was applied to the determination of different bread samples and was used to reveal the decrease of α-diketones in bread during the timeframe of a week.

The unique properties of metal-organic frameworks, such as diversity in structures and pore sizes, high surface area, shape selectivity and available to functionality make them as potential materials of the stationary phase for gas chromatography. Here we show an in situ growth approach to the fabrication of zeolite imidazolate framework-90 (ZIF-90) bonded capillary column for gas chromatography separation. ZIF-90 was directly grown onto the inner wall of the carboxyl modified capillary via the coordination between Zn(II) and carboxyl group. The fabricated ZIF-90 bonded capillary column acted as a weak polar stationary phase. It not only exhibits high capacity in the separation of linear molecules, but also offers excellent features for the separation of 2- and 3-substituted ketones.