Microorganisms and their hosts communicate with each other through an array of signals. The plant hormone auxin (indole-3-acetic acid; IAA) is central in many aspects development. Cyclodipeptides derivative diketopiperazines (DKPs) constitute a large class small molecules synthesized by microorganisms diverse noteworthy activities. Here, we present genetic, chemical, plant-growth data showing that Pseudomonas aeruginosa , the LasI quorum-sensing (QS) system controls production three...

Organic natural products, particularly vegetal secondary metabolites, represent a highlighted source for molecules usable many purposes, including synthesizing catalysts. Biocompatible metals can yield interesting coordination complexes to provide sustainable and valuable compounds. In the present paper, unique in their class (μ4-oxo)-hexakis(μ2-beyerenate)-tetra-zinc(II) (1) (μ4-oxo)-hexakis(μ2-kaurenate)-tetra-zinc(II) (2) are suggested as eco-friendly catalysts transesterification...

The molecular dynamics of PVA/AgnP composites were studied by dielectric spectroscopy (DS) in the 20–300°C temperature range. Improper water elimination leads to misinterpretation thermal relaxations PVA agreement with previous report for pristine PVA. evaporation and its plasticizing effect are more evident pure confirming existence strong interaction between OH groups chains AgnP. Dry films show a single nonlinear VFT dependence (from 45°C until melting) associated α ‐relaxation and,...

The new oxaziridinium salt 5 (R2 = TBDPS) is an effective reagent for the highly enantioselective oxidation of sulfides to sulfoxides with up >99% ee and good yields. As such, it represents a valuable nonmetallic alternative existing methods asymmetric sulfoxidation.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructural and stereochemical studies of naturally occurring longipinene derivativesLuisa U. Roman, Rosa E. Del Rio, Juan D. Hernandez, Carlos M. Cerda, Daniel Cervantes, Raul Castaneda, Pedro Joseph-NathanCite this: J. Org. Chem. 1985, 50, 21, 3965–3972Publication Date (Print):October 1, 1985Publication History Published online1 May 2002Published inissue 1 October...

Ambrox is an important fixative used in the manufacture of perfumes. It obtained through complex chemical synthesis routes with high costs. Recent research efforts at Institute Chemical and Biological Researches Universidad Michoacana have led to one-step from extracts Ageratina jocotepecana (an endemic plant State Michoacán Mexico). This new route attractive a manufacturing perspective. However, there are several challenges for industrial application this its incorporation supply chain...

Although demonstrated in 1975, vibrational circular dichroism (VCD) finally started to popularize during this century as a reliable tool determine the absolute configuration (AC) of organic molecules. This research field continues be very dynamic one, particular for study natural products which are unlimited source chiral It therefore turns interest summarize accomplishments published recent years and comment on some eventual difficulties that emerged rare cases complete AC determination...

Chemical investigation of the hexanes extracts Ageratina jocotepecana afforded (-)-(5S,9S,10S,13S)-labd-7-en-15-oic acid (1), methyl (-)-(5S,9S,10S,13S)-labd-7-en-15-oate (2), (+)-(5S,8R,9R,10S,13R)-8-hydroxylabdan-15-oic (3), and (-)-(5S,9S,10S,13Z)-labda-7,13-dien-15-oic (5). The coexistence (13R)- (13S)-labdanes in this member Asteraceae family was demonstrated by vibration circular dichroism measurements ester 2 (+)-(5S,8R,9R,10S,13R)-8-hydroxylabdan-15-oate (4) comparison to DFT...

The aerial parts of Ageratina glabrata afforded (−)-(3S,4R,5R,6S)-3,5,6-trihydroxy-1-menthene 3-O-β-d-glucopyranoside (1) and (−)-(3S,4S,6R)-3,6-dihydroxy-1-menthene (3). Acid hydrolysis 1 yielded (+)-(1R,4S,5R,6R)-1,5,6-trihydroxy-2-menthene (5) (+)-(1S,4S,5R,6R)-1,5,6-trihydroxy-2-menthene (6), while 3 (+)-(3S,4S,6R)-3,6-dihydroxy-1-menthene (10), (+)-(1R,4S,6R)-1,6-dihydroxy-2-menthene (11), (+)-(1S,4S,6R)-1,6-dihydroxy-2-menthene (12). structures the new compounds 1, 2, 5–9, 11 were...

A methodology to determine the enantiomeric excess and absolute configuration (AC) of natural epoxythymols was developed tested using five constituents Ageratina glabrata. The is based on purity determination employing 1,1′-bi-2-naphthol (BINOL) as a chiral solvating agent combined with vibrational circular dichroism (VCD) measurements calculations. conformational searching included an extensive Monte Carlo protocol that considered rotational barriers cover whole spaces....

Ageratina glabrata (Kunth) R.M. King & H. Rob., Asteraceae (syn. Eupatorium glabratum Kunth) is widely distributed throughout Mexico and popularly known as "chamizo blanco" "hierba del golpe" for its traditional use external analgesic remedy. Though species has been chemically studied, there are no experimentally asserted reports about possible effects which can be inferred from genus Ageratina. To fill the gap, we evaluated A. extracts in an animal model of nociception exploiting thermal...

Ultraviolet (UV) radiation harms the skin, causing oxidative damage, inflammation, and disruption of skin’s barrier function. There is considerable interest in identifying new natural ingredients with antioxidant anti-inflammatory properties to serve as adjuvants sunscreens. The flavonoid morin (1) can undergo structural modifications enhance its biological properties. aim this study was synthesize two morin-Schiff base derivatives, oxime (2) semicarbazone (3), comparing their...

Abstract The molecular dynamics of poly(vinyl alcohol) (PVA) were studied by dielectric spectroscopy and dynamic mechanical analysis in the 20–300°C range. well‐established plasticizing effect water on glass‐transition temperature ( T g ) PVA was revisited. Improper elimination has led to a misinterpretation thermal relaxations such that depressed for wet films (ca. 40°C) been assigned as secondary β relaxation number previous studies literature. In samples, two different...

In contrast to commercial Diospyros species, Mesoamerican fruit-producing species are scarcely known, particularly wild that might harbor desirable traits suitable for breeding. Thus, metabolomic, chemical, and antioxidant profiles of fruits harvested from cultivated digyna rekoi trees during consecutive winter seasons were obtained. Fruits in habitats having marked differences soil quality, climate, luminosity.D. larger less acid than D. fruits, whereas activity tended be higher fruits....