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https://www.readbyqxmd.com/read/28928524/volatiles-formation-in-gelled-emulsions-enriched-in-polyunsaturated-fatty-acids-during-storage-type-of-oil-and-antioxidant
#1
Lucía Gayoso, Candelaria Poyato, María Isabel Calvo, Rita Yolanda Cavero, Diana Ansorena, Iciar Astiasarán
Gelled emulsions with carrageenan are a novel type of emulsion that could be used as a carrier of unsaturated fatty acids in functional foods formulations. Lipid degradation through volatile compounds was studied in gelled emulsions which were high in polyunsaturated oils (sunflower or algae oil) after 49 days of storage. Aqueous Lavandula latifolia extract was tested as a natural antioxidant. Analysis of the complete volatile profile of the samples resulted in a total of 40 compounds, classified in alkanes, alkenes, aldehydes, ketones, acids, alcohols, furans, terpenes and aromatic hydrocarbons...
August 2017: Journal of Food Science and Technology
https://www.readbyqxmd.com/read/28926863/evaluation-of-cannabinoid-and-terpenoid-content-cannabis-flower-compared-to-supercritical-co2-concentrate
#2
Michelle Sexton, Kyle Shelton, Pam Haley, Mike West
A recent cannabis use survey revealed that 60% of cannabis users rely on smelling the flower to select their cannabis. Olfactory indicators in plants include volatile compounds, principally represented by the terpenoid fraction. Currently, medicinal- and adult-use cannabis is marketed in the United States with relatively little differentiation between products other than by a common name, association with a species type, and Δ-9 tetrahydrocannabinol/cannabidiol potency. Because of this practice, how terpenoid compositions may change during an extraction process is widely overlooked...
September 19, 2017: Planta Medica
https://www.readbyqxmd.com/read/28926261/late-stage-terpene-cyclization-by-an-integral-membrane-cyclase-in-the-biosynthesis-of-isoprenoid-epoxycyclohexenone-natural-products
#3
Man-Cheng Tang, Xiaoqing Cui, Xueqian He, Zhuang Ding, Tianjiao Zhu, Yi Tang, Dehai Li
Macrophorins are representative examples of isoprenoid epoxycyclohexenones containing cyclized drimane moieties. We located and characterized the biosynthetic gene cluster of macrophorin from Penicillium terrestris. MacJ encoded by this cluster was characterized to be the first example of a membrane-bound type-II terpene cyclase catalyzing the cyclization of meroterpenoids via direct protonation of the terminal olefinic bond in acyclic yanuthones. The late-stage functionalization and substrate promiscuity of MacJ make it a potential biocatalyst for the synthesis of macrophorin analogues...
September 19, 2017: Organic Letters
https://www.readbyqxmd.com/read/28926242/structure-function-studies-of-artemisia-tridentata-farnesyl-diphosphate-synthase-and-chrysanthemyl-diphosphate-synthase-by-site-directed-mutagenesis-and-morphogenesis
#4
J Scott Lee, Jian-Jung Pan, Gurusankar Ramamoorthy, C Dale Poulter
The amino acid sequences of farnesyl diphosphate synthase (FPPase) and chrysanthemyl diphosphate synthase (CPPase) from Artemisia tridentata ssp. Spiciformis, minus their chloroplast targeting regions, are 71% identical and 90% similar. FPPase efficiently and selectively synthesizes the "regular" sesquiterpenoid farnesyl diphosphate (FPP) by coupling isopentenyl diphosphate (IPP) to dimethylallyl diphosphate (DMAPP) and then to geranyl diphosphate (GPP). In contrast, CPPase is an inefficient promiscuous enzyme, which synthesizes the "irregular" monoterpenes chrysanthemyl diphosphate (CPP), lavandulyl diphosphate (LPP), and trace quantities of maconelliyl diphosphate (MPP) from two molecules of DMAPP, in addition to coupling IPP to DMAPP...
September 19, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28922556/structure-and-mechanism-of-the-monoterpene-cyclolavandulyl-diphosphate-synthase-that-catalyses-consecutive-condensation-and-cyclisation
#5
Tomohisa Kuzuyama, Takeo Tomita, Masaya Kobayashi, Yuma Karita, Yoko Yasuno, Tetsuro Shinada, Makoto Nishiyama
Here, we report the three-dimensional structure of cyclolavandulyl diphosphate (CLPP) synthase (CLDS), which consecutively catalyses the condensation of two molecules of dimethylallyl diphosphate (DMAPP) followed by cyclisation to form a cyclic monoterpene, CLPP. The structures of apo-CLDS and CLDS in complex with Tris, pyrophosphate, and Mg2+ ion were refined at 2.00 Å resolution and 1.73 Å resolution, respectively. CLDS adopts a typical fold for cis-prenyl synthases and forms a homo-dimeric structure. An in vitro reaction using a regiospecifically 2H-substituted DMAPP substrate revealed the intramolecular proton transfer mechanism of the CLDS reaction...
September 18, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28921887/chemical-components-biological-activities-and-toxicological-evaluation-of-the-fruit-aril-of-two-precious-plant-species-from-genus-taxus
#6
Na Li, Zheng Pan, Dan Zhang, Huaxing Wang, Bao Yu, Shengping Zhao, Jiajia Guo, Jianwei Wang, Ling Yao, Weiguo Cao
The fruit (aril) of the endangered genus Taxus plants is an abandoned herbal resource. Traditionally, people enthusiasticly focus on its bark, its renewable, tremendous arils fall into the soil with seeds after they are mature. The present research investigated the fruit of two species from the genus Taxus, Taxus chinensis var. mairei and Taxus media, with regards to their antioxidant and antihyperglycaemic activities, safety, and bioactive constituents. Results showed that T. chinensis var. mairei and T. media both had certain biological activities with T...
September 18, 2017: Chemistry & Biodiversity
https://www.readbyqxmd.com/read/28906071/construction-of-quaternary-stereogenic-centers-in-the-total-synthesis-of-natural-products
#7
Evgeny V Prusov
Total syntheses of the tetracyclic terpene waihoensene and the densely functionalized tetracyclic compound ryanodol have recently been reported. Both approaches constitute examples of the efficient and innovative construction of multiple quaternary centers.
September 14, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28905380/enhancing-blood-donor-skin-disinfection-using-natural-oils
#8
Meshari Alabdullatif, Imen Boujezza, Mohamed Mekni, Mariam Taha, Dilini Kumaran, Qi-Long Yi, Ahmed Landoulsi, Sandra Ramirez-Arcos
BACKGROUND: Effective donor skin disinfection is essential in preventing bacterial contamination of blood components with skin flora bacteria like Staphylococcus epidermidis. Cell aggregates of S. epidermidis (biofilms) are found on the skin and are resistant to the commonly used donor skin disinfectants chlorhexidine-gluconate and isopropyl alcohol. It has been demonstrated that essential oils synergistically enhance the antibacterial activity of chlorhexidine-gluconate. The objective of this study was to test plant-extracted essential oils in combination with chlorhexidine-gluconate or chlorhexidine-gluconate plus isopropyl alcohol for their ability to eliminate S...
September 14, 2017: Transfusion
https://www.readbyqxmd.com/read/28905185/hepatotoxicity-of-monoterpenes-and-sesquiterpenes
#9
REVIEW
Tomáš Zárybnický, Iva Boušová, Martin Ambrož, Lenka Skálová
Public interest in natural therapies has increased significantly over past decades. Herbs and herbal products are extensively consumed worldwide and they are generally considered as safe. However, this may not always be true as many cases of herb-induced liver injury are reported every year. The liver is a frequent target tissue of toxicity from all classes of toxicants as liver structure and function predispose it to high sensitivity to xenobiotics. The present review is focused on the hepatotoxic properties of monoterpenes and sesquiterpenes, plant secondary metabolites that represent the major components of essential oils wildly used in folk medicines, pharmaceutical industry and cosmetics...
September 13, 2017: Archives of Toxicology
https://www.readbyqxmd.com/read/28904624/pd-oac-2-ph3p-catalyzed-dimerization-of-isoprene-and-synthesis-of-monoterpenic-heterocycles
#10
Dominik Kellner, Maximilian Weger, Andrea Gini, Olga García Mancheño
The palladium-catalyzed dimerization of isoprene is a practical approach of synthesizing monoterpenes. Though several highly selective methods have been reported, most of them still required pressure or costly ligands for attaining the active system and desired selectivity. Herein, we present a simple and economical procedure towards the tail-to-tail dimer using readily available Pd(OAc)2 and inexpensive triphenylphosphine as ligand. Furthermore, simple screw cap vials are employed, allowing carrying out the reaction at low pressure...
2017: Beilstein Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28904620/18-hydroxydolabella-3-7-diene-synthase-a-diterpene-synthase-from-chitinophaga-pinensis
#11
Jeroen S Dickschat, Jan Rinkel, Patrick Rabe, Arman Beyraghdar Kashkooli, Harro J Bouwmeester
The product obtained in vitro from a diterpene synthase encoded in the genome of the bacterium Chitinophaga pinensis, an enzyme previously reported to have germacrene A synthase activity during heterologous expression in Escherichia coli, was identified by extensive NMR-spectroscopic methods as 18-hydroxydolabella-3,7-diene. The absolute configuration of this diterpene alcohol and the stereochemical course of the terpene synthase reaction were addressed by isotopic labelling experiments. Heterologous expression of the diterpene synthase in Nicotiana benthamiana resulted in the production of 18-hydroxydolabella-3,7-diene also in planta, while the results from the heterologous expression in E...
2017: Beilstein Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28904610/correction-dynamic-behavior-of-rearranging-carbocations-implications-for-terpene-biosynthesis
#12
Stephanie R Hare, Dean J Tantillo
[This corrects the article DOI: 10.3762/bjoc.12.41.].
2017: Beilstein Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28901763/bioassay-guided-isolation-of-antibacterial-metabolites-from-emericella-sp-tj29
#13
Yan He, Zhengxi Hu, Qin Li, Jinfeng Huang, Xiao-Nian Li, Hucheng Zhu, Junjun Liu, Jianping Wang, Yongbo Xue, Yonghui Zhang
Bioassay-guided isolation of metabolites from cultures of the plant-derived fungus Emericella sp. TJ29 yielded three new terpene-polyketide hybrid meroterpenoids, emervaridones A-C (1-3), two new polyketides, varioxiranediols A and B (5 and 6), and three known analogues (4, 7, and 8). The structures and absolute configurations of these new compounds were elucidated by spectroscopic analyses, single-crystal X-ray diffraction, Mo2(OAc)4-induced electronic circular dichroism (ECD) data, and ECD calculations. To date, only one compound (4) bearing the emervaridone-type carbocyclic skeleton has been reported...
September 13, 2017: Journal of Natural Products
https://www.readbyqxmd.com/read/28898524/enzymatic-addition-of-alcohols-to-terpenes-by-squalene-hopene-cyclase-variants
#14
Lisa C Kühnel, Bettina M Nestl, Bernhard Hauer
Squalene hopene cyclases (SHC) catalyze the polycyclization of squalene into a mixture of hopene and hopanol. Recently, amino acid residues lining the catalytic cavity of the SHC from Alicyclobacillus acidocaldarius were replaced by small and large hydrophobic amino acids. The alteration of leucine 607 to phenylalanine resulted in increased enzymatic activity towards the formation of an intermolecular farnesyl-farnesyl ether product from farnesol. Furthermore, the addition of small chain alcohols acting as nucleophiles led to the formation of non-natural ether-linked terpenoids and thus, to a significant alteration of the product pattern compared to wildtype...
September 12, 2017: Chembiochem: a European Journal of Chemical Biology
https://www.readbyqxmd.com/read/28898258/antioxidant-and-cytotoxic-activity-of-propolis-of-plebeia-droryana-and-apis-mellifera-hymenoptera-apidae-from-the-brazilian-cerrado-biome
#15
Thaliny Bonamigo, Jaqueline Ferreira Campos, Alex Santos Oliveira, Heron Fernandes Vieira Torquato, José Benedito Perrella Balestieri, Claudia Andrea Lima Cardoso, Edgar Julian Paredes-Gamero, Kely de Picoli Souza, Edson Lucas Dos Santos
Propolis is a complex bioactive mixture produced by bees, known to have different biological activities, especially in countries where there is a rich biodiversity of plant species. The objective of this study was to determine the chemical composition and evaluate the antioxidant and cytotoxic properties of Brazilian propolis from the species Plebeia droryana and Apis mellifera found in Mato Grosso do Sul, Brazil. In the ethanolic extracts of P. droryana propolis (ExEP-P) and A. mellifera (ExEP-A) acids, phenolic compounds, terpenes and tocopherol were identified as major compounds...
2017: PloS One
https://www.readbyqxmd.com/read/28895237/a-comprehensive-characterisation-of-rosemary-tea-obtained-from-rosmarinus-officinalis-l-collected-in-a-sub-humid-area-of-tunisia
#16
Mariem Achour, Raquel Mateos, Maha Ben Fredj, Ali Mtiraoui, Laura Bravo, Saad Saguem
INTRODUCTION: Rosemary (Rosmarinus officinalis L.) is an aromatic plant common in Tunisia and it is widely consumed as a tea in traditional cuisine and in folk medicine to treat various illnesses. Currently, most research efforts have been focused on rosemary essential oil, alcoholic and aqueous extracts, however, little is reported on rosemary infusion composition. OBJECTIVE: To investigate compounds present in rosemary tea obtained from Rosmarinus officinalis L...
September 12, 2017: Phytochemical Analysis: PCA
https://www.readbyqxmd.com/read/28888200/emulsification-efficacy-of-quillaja-saponins-at-very-low-concentration-model-development-and-role-of-alcohols
#17
Amanda Schober, Jian Zhang, Anand Subramaniam, Valery Normand
The present study aims at quantifying interfacial coverage of a biosurfactant (Quillaja saponins) and understanding the impact of flavor and fragrance alcohols on emulsification efficacy of the biosurfactant in a surfactant-oil-matrix system. Emulsions were prepared using limonene, alkanes (C8, C12, and C16) or limonene ̶ alcohol (linalool and C6C10 alcohols) mixtures at different ratios as oil phase stabilized by Quillaja saponins at very low concentrations (0.005-0.05% w/w). Droplet size was measured and size distributions were numerized to determine surface and volume average droplet diameters of bimodal emulsions...
September 6, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/28887468/the-network-of-plants-volatile-organic-compounds
#18
Gianna Vivaldo, Elisa Masi, Cosimo Taiti, Guido Caldarelli, Stefano Mancuso
Plants emission of Volatile Organic Compounds (VOCs) is involved in a wide class of ecological functions, as VOCs play a crucial role in plants interactions with biotic and abiotic factors. Accordingly, they vary widely across species and underpin differences in ecological strategy. In this paper, VOCs spontaneously emitted by 109 plant species (belonging to 56 different families) have been qualitatively and quantitatively analysed in order to provide an alternative classification of plants species. In particular, by using bipartite networks methodology from Complex Network Theory, and through the application of community detection algorithms, we show that is possible to classify species according to chemical classes such as terpenes and sulfur compounds...
September 8, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28885582/effect-of-vertical-shoot-positioned-scott-henry-geneva-double-curtain-arch-cane-and-parral-training-systems-on-the-volatile-composition-of-albari%C3%A3-o-wines
#19
Mar Vilanova, Zlatina Genisheva, Miguel Tubio, Katia Álvarez, Jose Ramón Lissarrague, José Maria Oliveira
Viticultural practices influence both grape and wine quality. The influence of training systems on volatile composition was investigated for Albariño wine from Rías Baixas AOC in Northwest Spain. The odoriferous contribution of the compounds to the wine aroma was also studied. Volatile compounds belonging to ten groups (alcohols, C₆-compounds, ethyl esters, acetates, terpenols, C13-norisoprenoids, volatile phenols, volatile fatty acids, lactones and carbonyl compounds) were determined in Albariño wines from different training systems, Vertical Shoot-Positioned (VSP), Scott-Henry (SH), Geneva Double-Curtain (GDC), Arch-Cane (AC), and Parral (P) during 2010 and 2011 vintages...
September 8, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28883829/genomic-analysis-of-terpene-synthase-family-and-functional-characterization-of-seven-sesquiterpene-synthases-from-citrus-sinensis
#20
Berta Alquézar, Ana Rodríguez, Marcos de la Peña, Leandro Peña
Citrus aroma and flavor, chief traits of fruit quality, are derived from their high content in essential oils of most plant tissues, including leaves, stems, flowers, and fruits. Accumulated in secretory cavities, most components of these oils are volatile terpenes. They contribute to defense against herbivores and pathogens, and perhaps also protect tissues against abiotic stress. In spite of their importance, our understanding of the physiological, biochemical, and genetic regulation of citrus terpene volatiles is still limited...
2017: Frontiers in Plant Science
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