Increasingly, molecular chemistry and pharmacology are complementing classical studies in the field of archaeology. In this case, we present the results of the chemical study of pipe residues found in the context of an archaeological mission (AROMA mission: Archaeology of the Exercise of Royal and Magico-Religious Power) in the royal palaces of Abomey (Benin), dating from the 17th-19th century. The search for many products was carried out (mainly tobacco, cannabis) but surprisingly only highlighted the presence of caffeine residues.
View Article and Find Full Text PDFIndigo and indirubin are derived from indoxyl molecules, which generally occur as indoxyl glycosides in woad (Isatis tinctoria L.) and other indigo-producing plants. Indoxyl glycosides are biosynthesized from indole via 3-hydroxylation to form indoxyl, followed by one or more glycosylations.
View Article and Find Full Text PDFAs cannabis use increases among reproductive-aged women, there is a growing need to better understand the presence of cannabinoids in milk produced by women using cannabis. It is unclear how concentrations of cannabinoids such as delta-9-tetrahydrocannabinol (Δ-THC) persist in milk after cannabis use and what factors contribute to variation in milk Δ-THC concentrations. Our objectives were to measure cannabinoids in human milk following cannabis abstention, after single and repeated instances of cannabis use, and identify factors contributing to concentration variation.
View Article and Find Full Text PDFRootstock selection and crop load adjustment are key practices in apple orchard management; nevertheless, the effects of rootstocks and crop load levels on important physiological processes of the scions, such as photosynthetic performance and carbohydrate accumulation, are still unclear. To investigate the impact of different rootstocks and crop load levels on scion photosynthesis and carbohydrate buildup, in 2020, 'Honeycrisp' trees grafted on rootstocks 'G.41', 'G.
View Article and Find Full Text PDFPotato () is affected by several viral pathogens with the most economically damaging being potato virus Y (PVY). At least nine biologically distinct variants of PVY are known to attack potato, with necrotic types named PVY and PVY being the most recent additions to the list. So far, the molecular plant-virus interactions underlying this pathogenicity are not fully understood.
View Article and Find Full Text PDFUnlike the bicellular glands characteristic of all known excreting grasses, unique single-celled salt glands were discovered in the only salt tolerant species of the genus Oryza, Oryza coarctata. Salt tolerance has evolved frequently in a large number of grass lineages with distinct difference in mechanisms. Mechanisms of salt tolerance were studied in three species of grasses characterized by salt excretion: C wild rice species Oryza coarctata, and C species Sporobolus anglicus and Urochondra setulosa.
View Article and Find Full Text PDFMercaptoethane sulfonate or coenzyme M (CoM) is the smallest known organic cofactor and is most commonly associated with the methane-forming step in all methanogenic archaea but is also associated with the anaerobic oxidation of methane to CO in anaerobic methanotrophic archaea and the oxidation of short-chain alkanes in species. It has also been found in a small number of bacteria capable of the metabolism of small organics. Although many of the steps for CoM biosynthesis in methanogenic archaea have been elucidated, a complete pathway for the biosynthesis of CoM in archaea or bacteria has not been reported.
View Article and Find Full Text PDFSalicylic acid (SA) is a phytohormone that plays manifold roles in plant growth, defense, and other aspects of plant physiology. The concentration of free SA in plants is fine-tuned by a variety of structural modifications. SA is produced by all land plants, yet it is not known whether its metabolism is conserved in all lineages.
View Article and Find Full Text PDFPlants live in association with microorganisms that positively influence plant development, vigor, and fitness in response to pathogens and abiotic stressors. The bulk of the plant microbiome is concentrated belowground at the plant root-soil interface. Plant roots secrete carbon-rich rhizodeposits containing primary and secondary low molecular weight metabolites, lysates, and mucilages.
View Article and Find Full Text PDFPlants deploy a variety of chemical and physical defenses to protect themselves against herbivores and pathogens. Organic farming seeks to enhance these responses by improving soil quality, ultimately altering bottom up regulation of plant defenses. While laboratory studies suggest this approach is effective, it remains unclear whether organic agriculture encourages more-active plant defenses under real-world conditions.
View Article and Find Full Text PDF'Candidatus Liberibacter asiaticus' is a fastidious bacterium and a putative agent of citrus greening disease (a.k.a.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
July 2018
Numerous methoxylated flavonoids exhibit pronounced bioactivities. Their biotechnological production and diversification are therefore of interest to pharmaceutical and nutraceutical industries. We used a set of enzymes from sweet basil (Ocimum basilicum) to construct five strains of Saccharomyces cerevisiae producing 8- and/or 6-substituted, methoxylated flavones from their natural precursor apigenin.
View Article and Find Full Text PDFSalvia divinorum (Lamiaceae) is an annual herb used by indigenous cultures of Mexico for medicinal and ritual purposes. The biosynthesis of salvinorin A, its major bioactive neo-clerodane diterpenoid, remains virtually unknown. This investigation aimed to identify the enzyme that catalyzes the first reaction of salvinorin A biosynthesis, the formation of (-)-kolavenyl diphosphate [(-)-KPP], which is subsequently dephosphorylated to afford (-)-kolavenol.
View Article and Find Full Text PDFPromoting brown adipose tissue (BAT) development is an attractive strategy for the treatment of obesity, as activated BAT dissipates energy through thermogenesis; however, the mechanisms controlling BAT formation are not fully understood. We hypothesized that as a master regulator of energy metabolism, AMP-activated protein kinase (AMPK) may play a direct role in the process and found that AMPKα1 (PRKAA1) ablation reduced Prdm16 expression and impaired BAT development. During early brown adipogenesis, the cellular levels of α-ketoglutarate (αKG), a key metabolite required for TET-mediated DNA demethylation, were profoundly increased and required for active DNA demethylation of the Prdm16 promoter.
View Article and Find Full Text PDFBay laurel (Laurus nobilis L.) is an agriculturally important tree used in food, drugs, and the cosmetics industry. Many of the health beneficial properties of bay laurel are due to volatile terpene metabolites that they contain, including various norisoprenoids.
View Article and Find Full Text PDFSmall molecule demethylation is considered unusual in plants. Of the studied instances, the N-demethylation of nicotine is catalyzed by a Cyt P450 monooxygenase, while the O-dealkylation of alkaloids in Papaver somniferum is mediated by 2-oxoglutarate-dependent dioxygenases (2-ODDs). This report describes a 2-ODD regiospecifically catalyzing the 7-O-demethylation of methoxylated flavones in peltate trichomes of sweet basil (Ocimum basilicum L.
View Article and Find Full Text PDFThe apple tree (Malus sp.) is an agriculturally and economically important source of food and beverages. Many of the health beneficial properties of apples are due to (poly)phenolic metabolites that they contain, including various dihydrochalcones.
View Article and Find Full Text PDFMost elucidated hydroxylations in plant secondary metabolism are catalyzed by oxoglutarate- or cytochrome P450-dependent oxygenases. Numerous hydroxylations still evade clarification, suggesting that they might be performed by alternative enzyme types. Here, we report the identification of the flavone 8-hydroxylase (F8H) in sweet basil (Ocimum basilicum L.
View Article and Find Full Text PDFRegioselective 6-,7-,8-,3'-, and 4'-O-methylations underlie the structural diversity of lipophilic flavones produced in the trichomes of sweet basil (Ocimum basilicum L.). The positions 6, 7, and 4' are methylated by a recently described set of cation-independent enzymes.
View Article and Find Full Text PDFConiferyl alcohol 9-O-methyltransferase from Linum nodiflorum (Linaceae) catalyzes the unusual methylation of the side-chain hydroxyl group of coniferyl alcohol. The protein was heterologously expressed in Escherichia coli as a hexahistidine derivative and purified for crystallization. Diffracting crystals were obtained of the pure protein and of its selenomethionine derivative, as well as of complexes with coniferyl alcohol and with S-adenosyl-L-homocysteine together with coniferyl alcohol 9-O-methyl ether (PDB entries 4ems, 4e70 and 4evi, respectively).
View Article and Find Full Text PDFLipophilic flavonoids found in the Lamiaceae exhibit unusual 6- and 8-hydroxylations whose enzymatic basis is unknown. We show that crude protein extracts from peltate trichomes of sweet basil (Ocimum basilicum L.) cultivars readily hydroxylate position 6 of 7-O-methylated apigenin but not apigenin itself.
View Article and Find Full Text PDFPolymethoxylated flavonoids occur in a number of plant families, including the Lamiaceae. To date, the metabolic pathways giving rise to the diversity of these compounds have not been studied. Analysis of our expressed sequence tag database for four sweet basil (Ocimum basilicum) lines afforded identification of candidate flavonoid O-methyltransferase genes.
View Article and Find Full Text PDFCell cultures of Linum species store 6-methoxypodophyllotoxin (MPTOX), podophyllotoxin (PTOX) and related lignans as O-glucosides. UDP-glucose:(M)PTOX 7-O-glucosyltransferase has been detected and characterised in protein preparations of suspension-cultured cells of Linum nodiflorum L. (Linaceae).
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