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Sugar esters display surface-active properties, wetting, emulsifying, and other physicochemical phenomena following their amphipathic nature and recognize distinct biological activity. The development of nutritional pharmaceuticals and other applications remains of great interest. Herein, three novel homologous series of several N-mono-fatty acyl amino acid glucosyl esters were synthesized, and their physicochemical properties and biological activities were evaluated. The design and preparation of these esters were chemically performed via the reaction of glucose with different fatty acyl amino acids as renewable starting materials, with the suggestion that they would acquire functional characteristics superior and competitive to certain conventional surfactants. The synthesized products are characterized using FTIR, 1H-NMR, and 13C-NMR spectroscopy. Further, their physicochemical properties, such as HLB, CMC, Γmax, γCMC, and Amin, were determined. Additionally, their antimicrobial and anticancer efficiency were assessed. The results indicate that the esters' molecular structure, including the acyl chain length and the type of amino acid, significantly influences their properties. The measured HLB ranged from 8.84 to 12.27, suggesting their use as oil/water emulsifiers, wetting, and cleansing agents. All esters demonstrate promising surface-active characteristics, with moderate to high foam production with good stability. Notably, compounds 6-O-(N-dodecanoyl, tetradecanoyl cysteine)-glucopyranose (34, 35), respectively and 6-O-(N-12-hydroxy-9-octadecenoyl cysteine)-glucopyranose (38) display superior foamability. Wetting efficiency increased with decreasing the chain length of the acyl group. The storage results reveal that increasing the fatty acyl hydrophobe length enhances the derived emulsion's stability for up to 63 days. Particularly, including cysteine in these glucosyl esters improves wetting, foaming, and emulsifying potentialities. Furthermore, the esters exhibit antibacterial activity against several tested Gram-positive and Gram-negative bacteria and fungi. On the other hand, they show significant antiproliferative effects on some liver tumor cell lines. For instance, compounds 6-O-(N-12-hydroxy-9-octadecenoylglycine)-glucopyranose (28), 6-O-(N-dodecanoyl, hexadecanoyl, 9-octadecenoyl and 12-hydroxy-9-octadecenoylvaline)- glucopyranose (29, 31, 32 and 33), respectively in addition to the dodecanoyl, hexadecanoyl, 9-octadecenoyl and 12-hydroxy-9-octadecenoyl cysteine glucopyranose (34, 36, 37 and 38), respectively significantly inhibit the examined cancer cells. [ABSTRACT FROM AUTHOR]

This article, published in Chemistry of Natural Compounds, explores the use of fungi to produce fine chemicals through whole cell cultures. The researchers specifically focus on the transformation of the fertility agent Dydrogesterone (DYD) using the fungus Aspergillus flavus. They provide spectroscopic data for the compounds formed during this transformation and conduct antimicrobial bioassays. The article highlights the potential of fungi in modifying steroidal and non-steroidal compounds and suggests the need for further research in this area. The study found that A. flavus was able to transform DYD into various products, and the antifungal activity of these products was tested against different fungi and bacteria. The document also provides details on the experimental methods used in the study. [Extracted from the article]

Amides are important intermediates in organic chemistry and the pharmaceutical industry, but their low reactivity requires catalysts and/or severe reaction conditions for esterification. Here, a novel approach was devised to convert amides into esters without the use of transition metals. The method effectively overcomes the inherent low reactivity of amides by employing dimethylsulfate-mediated reaction to activate the C-N bonds. To confirm the proposed reaction mechanism, control experiments and density functional theory (DFT) calculations were conducted. The method demonstrates a wide array of substrates, including amides with typical H/alkyl/aryl substitutions, N,N-disubstituted amides, amides derived from alkyl, aryl, or vinyl carboxylic acids, and even amino acid substrates with stereocentres. Furthermore, we have shown the effectiveness of dimethylsulfate in removing acyl protective groups in amino derivatives. This study presents a method that offers efficiency and cost-effectiveness in broadening the esterification capabilities of amides, thereby facilitating their increased utilization as synthetic compounds in diverse transformations. Amides are important intermediates in organic chemistry and the pharmaceutical industry, but their low reactivity requires catalysts and/or harsh reaction conditions to esterify them. Here, the authors report a versatile and mild dimethyl sulfate-mediated reaction to activate and esterify C—N bonds, achieving up to 95% amide bond cleavage. [ABSTRACT FROM AUTHOR]

Protein post-translational modifications (PTMs) with various acyl groups play central roles in Streptomyces. But whether these acyl groups can be further modified, and the influences of these potential modifications on bacterial physiology have not been addressed. Here in Streptomyces roseosporus with rich crotonylation, a luciferase monooxygenase LimB is identified to elaborately regulate the crotonylation level, morphological development and antibiotic production by oxidation on the crotonyl groups of an acetyl-CoA synthetase Acs. This chemical modification on crotonylation leads to Acs degradation via the protease ClpP1/2 pathway and lowered intracellular crotonyl-CoA pool. Thus, we show that acyl groups after PTMs can be further modified, herein named post-PTM modification (PPM), and LimB is a PTM modifier to control the substrate protein turnover for cell development of Streptomyces. These findings expand our understanding of the complexity of chemical modifications on proteins for physiological regulation, and also suggest that PPM would be widespread. Protein crotonylation, as one of post-translational modifications (PTMs), can be further modified, herein named post-PTM (PPM) by a monooxygenase in Streptomyces to regulate substrate protein turnover and cell physiology. [ABSTRACT FROM AUTHOR]

Polyketides are a class of natural products with astonishing structural diversities, fascinating biological activities, and a versatile of applications. In polyketides biosynthesis, acyltransferases (ATs) are the 'gatekeeping' enzymes selecting the specific CoA-activated acyl groups as building blocks and transferring them onto the phosphopantetheine arm of acyl carrier proteins (ACPs) to enable the following condensation reactions to assemble the polyketide chain. Herein, the Art2 protein from aurantinins, a group of the antibacterial polyketides, is characterized in vitro as an AT that can load a CoA-activated succinyl unit onto the first ACP domain of Art17 (ACPArt17-1). In addition, another two proteins, GbnB and EtnB, involved in the biosynthesis of gladiolin and etnangien respectively, were traced by literature mining, homologous searching, and product structure analysis and then identified as functional succinyl-CoA ATs by the ACPArt17-1 assays. Taken together, by the assay method employing ACPArt17-1 as an acyl acceptor, we identified three ATs that can introduce a succinyl unit into the polyketide assembly line, which enriches the toolbox of polyketide biosynthetic enzymes and sets a stage for incorporating a succinyl unit into polyketide backbones in synthetic biological manners. Key points: • Three acyltransferases that are able to load ACP with a succinyl unit were characterized in vitro. • ACPArt17-1 can be used as an acceptor to assay succinyl-CoA AT from different polyketides. • The succinyl unit can be incorporated into polyketides assembly process. [ABSTRACT FROM AUTHOR]

Lysine Nɛ-acylations, such as acetylation or succinylation, are post-translational modifications that regulate protein function. In mitochondria, lysine acylation is predominantly non-enzymatic, and only a specific subset of the proteome is acylated. Coenzyme A (CoA) can act as an acyl group carrier via a thioester bond, but what controls the acylation of mitochondrial lysines remains poorly understood. Using published datasets, here we found that proteins with a CoA-binding site are more likely to be acetylated, succinylated, and glutarylated. Using computational modeling, we show that lysine residues near the CoA-binding pocket are highly acylated compared to those farther away. We hypothesized that acyl-CoA binding enhances acylation of nearby lysine residues. To test this hypothesis, we co-incubated enoyl-CoA hydratase short chain 1 (ECHS1), a CoA-binding mitochondrial protein, with succinyl-CoA and CoA. Using mass spectrometry, we found that succinyl-CoA induced widespread lysine succinylation and that CoA competitively inhibited ECHS1 succinylation. CoA-induced inhibition at a particular lysine site correlated inversely with the distance between that lysine and the CoA-binding pocket. Our study indicated that CoA acts as a competitive inhibitor of ECHS1 succinylation by binding to the CoA-binding pocket. Together, this suggests that proximal acylation at CoA-binding sites is a primary mechanism for lysine acylation in the mitochondria. [ABSTRACT FROM AUTHOR]

The polysaccharide capsule surrounding bacterial cell plays an important role in pathogenesis of infections caused by the opportunistic pathogen Acinetobacter baumannii by providing protection from external factors. The structures of the capsular polysaccharide (CPS) produced by A. baumannii isolates and the corresponding CPS biosynthesis gene clusters are highly diverse, although many of them are related. Many types of A. baumannii CPSs contain isomers of 5,7-diamino-3,5,7,9-tetradeoxynon-2-ulosonic acid (DTNA). Three of these isomers, namely acinetaminic acid (l-glycero-l-altro isomer), 8-epiacinetaminic acid (d-glycero-l-altro isomer), and 8-epipseudaminic acid (d-glycero-l-manno isomer), have not been found so far in naturally occurring carbohydrates from other species. In A. baumannii CPSs, DTNAs carry N-acyl substituents at positions 5 and 7; in some CPSs, both N-acetyl and N-(3-hydroxybutanoyl) groups are present. Remarkably, pseudaminic acid carries the (R)-isomer and legionaminic acid carries the (S)-isomer of the 3-hydroxybutanoyl group. The review addresses the structure and genetics of biosynthesis of A. baumannii CPSs containing di-N-acyl derivatives of DTNA. [ABSTRACT FROM AUTHOR]

Unrestricted reproduction and spread of pest had caused great damage to the quality and yield of crops in recent years. Besides the use of traditional chemical pesticides, natural products also make a huge contribution against pests. Chasmanthinine, a diterpenoid alkaloid isolated from Aconitum franchetii var. villosulum, shown extremely antifeedant activity against Spodoptera exigua. Therefore, a series of novel Chasmanthinine derivatives were synthesized and their biological activity was studied in this work. Compound 33 showed the strongest antifeedant activity (EC50 = 0.10 mg/cm2) among all the test compounds. The mechanism research of 33 revealed that its antifeedant effect was related to the inhibition of carboxylesterase (CES), and proved the thiophene acyl group could form a strong binding effect with CES by molecular docking. Moreover, compound 10 exhibited the strongest cytotoxicity (IC50 = 12.87 μM) against Sf9 cell line and moderate contact toxicity. The mechanism research indicated that compound 10 could induce Sf9 cells apoptosis. In summary, the results lay a foundation for the application of diterpene alkaloids in plant protection. [ABSTRACT FROM AUTHOR]

Unrestricted reproduction and spread of pest had caused great damage to the quality and yield of crops in recent years. Besides the use of traditional chemical pesticides, natural products also make a huge contribution against pests. Chasmanthinine, a diterpenoid alkaloid isolated from Aconitum franchetii var. villosulum, shown extremely antifeedant activity against Spodoptera exigua. Therefore, a series of novel Chasmanthinine derivatives were synthesized and their biological activity was studied in this work. Compound 33 showed the strongest antifeedant activity (EC50 = 0.10 mg/cm2) among all the test compounds. The mechanism research of 33 revealed that its antifeedant effect was related to the inhibition of carboxylesterase (CES), and proved the thiophene acyl group could form a strong binding effect with CES by molecular docking. Moreover, compound 10 exhibited the strongest cytotoxicity (IC50 = 12.87 μM) against Sf9 cell line and moderate contact toxicity. The mechanism research indicated that compound 10 could induce Sf9 cells apoptosis. In summary, the results lay a foundation for the application of diterpene alkaloids in plant protection. [ABSTRACT FROM AUTHOR]

The reaction of sodium ricinoleate with thiophosphoryl trichloride under various conditions was studied. At a high concentration of sodium ricinoleate, thiophosphoryl trichloride reacts primarily with the alcohol OH group, and the isolated compound contains a sodium acyl group, which was confirmed by IR, 1H, 13C, 31P NMR spectroscopy and elemental analysis data. When the salt solution is diluted 5 times, the reaction proceeds by the mechanism of nucleophilic substitution both on the carboxylate and on the alcohol group. According to gel chromatography data, the molecular weight of the reaction product is close to trisubstituted thiophosphate, the composition and structure of which are confirmed by elemental analysis and IR, 1Н, 13С, 31Р NMR spectroscopy and diffractometry data. During chromatography on silica gel, it decomposes, as during hydrolysis in a slightly acidic medium. [ABSTRACT FROM AUTHOR]

Phloroglucinols of Dryopteris fragrans (L.) Schott plant show strong antifungal activity. In previous work, we isolated a wide range of phloroglucinols from the plant and found that pseudoaspidinol of D. fragrans and its structural modifications (methylphloroglucinol derivatives) showed stronger antifungal activity and confirmed that the butyryl group of these compounds accounted for this activity. In this study, we designed a series of phloroglucinol derivatives (A1–A9) and methylphloroglucinol derivatives (B1–B9) by introducing acyl groups with diverse carbon numbers in the C-2 position, synthesized these compounds, and evaluated the anti-dermatophyte activity of compounds A1–A5 and B1–B5 on Trichophyton rubrum and Trichophyton mentagrophytes fungal species. The results showed that compound A5 exhibited the strongest activity. These compounds can be used as leads for the development of new antifungal agents. [ABSTRACT FROM AUTHOR]

In this paper, chitosan/Fe3O4/graphene oxide hydrogel was synthesized then modified with 2,6-pyridinedicarbonyl dichloride to obtain a novel composite hydrogel. The modified hydrogel formed via interfacial polymerization crosslinking of amino groups of chitosan in chitosan/Fe3O4/graphene oxide hydrogel with acyl groups of 2,6-pyridinedicarbonyl dichloride. The synthesized hydrogels were characterized using different tools such as FT-IR, XRD, TGA, VSM, BET, HR-TEM, and FE-SEM instruments. The successful modification was demonstrated through FE-SEM where sphere and rod shapes were noticed due to the presence of Fe3O4/graphene oxide. The XRD diffraction peaks of the modified hydrogel were close to that of Fe3O4 without any changes in its structure. Also, there are no distinguishing XRD diffraction peaks due to the graphene oxide owing to the disorders that happen in graphene during the formation of the composite. The modified hydrogel was efficiently utilized for removing eriochrome black T and methylene blue dyes from aqueous media. The optimum pH for removing eriochrome black-T and methylene blue dyes is 2 and 8, respectively. Also, the optimum contact time and temperature for removing eriochrome black-T and methylene blue dyes are 140 min and 318 K, respectively. The maximum adsorption capacity of the modified hydrogel toward eriochrome black T and methylene blue dyes is 289.85 and 261.78 mg/g, respectively. The equilibrium and kinetic results were best fitted to the Langmuir isotherm and pseudo-second-order. The thermodynamic results confirmed that the adsorption process was spontaneous and endothermic. [ABSTRACT FROM AUTHOR]

The review considers the known strategies for the synthesis of fragments of arabinogalactan and lipoarabinomannan, polysaccharides that are contained in the cell walls of causative agent of tuberculosis Mycobacterium tuberculosis, as well as other related oligosaccharides containing arabinofuranose residues, using silyl substituents both for the differentiation of hydroxy groups in monosaccharide blocks and as stereodirecting groups during formation of a β-arabinofuranoside bond. In particular, the use of silyl groups (in combination with orthogonal to them acyl groups) allows the stereoselective synthesis of arabinans without the involvement of benzyl groups removable under reducing conditions, which is unacceptable in the presence of fragments sensitive to hydrogenolysis. This significantly simplifies the synthesis of 1,2-cis-linked oligosaccharides containing multiple bonds or azide groups, in particular, in aglycone, which is extremely important for the preparation of neoglycoconjugates both by converting the azide to an amine, followed by covalent binding to a carrier, and by conducting click-chemistry reactions using the 1,3-dipolar cycloaddition of azides to alkynes. [ABSTRACT FROM AUTHOR]

Methods were developed for the synthesis of new pyrido[2,3-d]pyrimidin-5-ones and pyrido[2,3-d]pyrimidin-7-ones from 5-acetyl-N-acyl-6-amino-4-methylsulfanyl-2-phenylpyrimidines. Heating the latter with MeONa at reflux in BuOH led to selective formation of pyrido[2,3-d]pyrimidin-5-ones or pyrido[2,3-d]pyrimidin-7-ones (containing an intact SMe group or resulting in its substitution with OBu group), depending on the nature of the acyl group. The possible substitution of SMe and OBu groups in pyridopyrimidinones was explored by using BnNH2. It was demonstrated that prior oxidation of SMe group with m-chloroperbenzoic acid allowed for simpler introduction of the NHBn moiety. [ABSTRACT FROM AUTHOR]

Some of the kinetic parameters of esterifications of aliphatic acids and alcohols involving biocatalysts in nonaqueous media were analyzed using mathematical modeling. The kinetic equations were solved by the modified Runge–Kutta–Merson method, which provided the specified accuracy. The acids of the C3–C8 series were used as donors of acyl groups; the alcohols of the C4–C11 series, as acceptors; and nonimmobilized enzymes Lipozyme CALB and pancreatic lipase, as biocatalysts. An analysis of the calculated data made it possible to evaluate the occurrence of esterification, hydrolysis, and secondary esterification similar to autocatalysis in the system. Secondary esterification occurs because water that formed in primary esterification enters the hydration shell of the active site of enzyme, increasing its catalytic properties. [ABSTRACT FROM AUTHOR]

Glandular trichomes on the surface of Solanaceae species produce acyl sugars that are species-, and cultivar-specific. Acyl sugars are known to possess insecticidal, antibiotic, and hormone-like properties, and as such have great potential as a class of naturally occurring pesticides and antibiotics. The objective of this work was to analyze the acyl composition of acyl sugars in the leaf trichome exudate from selected Nicotiana species and to follow the inheritance of acyl content in their hybrids. Trichome exudates were collected, and the acyl profiles of acyl sugars were identified via GC–MS. The variations in acyl group inheritance in the hybrids (a single parent resemblance, missing, complementary, and novel groups) matched the patterns described in the literature for a variety of secondary metabolites. However, we did not find a complementation of major parental acyl groups. Instead, in some hybrids we observed a dynamic change in the proportions of acyl groups, distinguishing the acyl group profiles as novel. We observed paternal (i.e. N. tabacum cv. Turkish Samsun × N. benthamiana hybrids) and maternal (i.e. N. tabacum cv. Samsun-nn × N. otophora) inheritance patterns, novel acyl profiles (N. excelsior hybrids), and missing acyl groups (N. excelsiana). Selective inheritance of some acyl groups in the hybrids of N. benthamiana (4- and 5-methylheptanoic isomers) or N. alata (octanoate) was found. Suggestions are given to explain certain patterns of inheritance. The data presented here contribute to the body of knowledge about the effect of interspecific hybridization on the secondary metabolites by including acylsugar acyl groups that have not been studied previously. [ABSTRACT FROM AUTHOR]

Alkaline hydrolysis of ethyl 4-nitrophenyl ethylphosphonate in organized nanosized systems based on dimeric surfactants and co-micelles [with cetyl(trimethyl)ammonium bromide as co-surfactant]. Transfer of the reaction from water to the micellar pseudophase accelerates the alkaline hydrolysis by a factor of 10 to 170. The maximum acceleration has been observed for tetraalkylammonium surfactant 16–3–16. The main factors responsible for micellar effects of surfactants are both substrate concentration and change of the reactivity of hydroxide ion in going from bulk water to surfactant micelles. [ABSTRACT FROM AUTHOR]

New furo[2,3-b]pyridine and pyrido[3′,2′:4,5]furo[3,2-d]pyrimidine derivatives were synthesized from ethyl 5-alkyl-1-amino-6,7,8,9-tetrahydrofuro[2,3-c]isoquinoline-2-carboxylates. Reactions of ethyl 5-alkyl-1-[(aminoacetyl)amino]-6,7,8,9-tetrahydrofuro[2,3-c]isoquinoline-2-carboxylates with hydrazine hydrate in¬volved not only cyclization but also hydrazinolysis and elimination of the acyl group. [ABSTRACT FROM AUTHOR]

Polyurethane (PU) is a most commonly used polymer for various application such as rigid and flexible foams, coatings etc. Also another class known as biodegradable PUs are used in specialized medical fields like soft-tissue engineering, regenerative medicine and also drug delivery systems, However, the degradation of the polyurethanes derived traditionally from general diisocyanates like 4,40-methylene diphenyl diisocyanate and toluene diisocyanate gives toxic products. Therefore, it is imperative to find an alternative route for the synthesis of PU which involves least or no toxic reagents. The consequently formed products are named non-isocyanate polyurethanes (NIPU). Recently, few alternative synthesis methods have been suggested by many researchers like a synthesis of polyhydroxyurethanes by polyaddition of diamines with cyclic carbonates. Such methods use functionalized vegetable oil as a biocompatible monomer which has led to a new range of biodegradable, renewable and sustainable source for NIPUs. Use of cyclocarbonates class of compounds has shown potential in the preparation of green PUs. Self-polycondensation reactions between AB-type fatty monomers bearing acyl azide and hydroxyl functionalities will take part. Here, the isocyanate group formation takes place in situ via Curtius rearrangement. The only disadvantage of this method is that the acyl azide groups are obtained by the harmful reaction of sodium azide with carboxylic acids. Bio-renewable sources represent a rich source of precursors for the synthesis of polyols and polyisocyanates. Many such sustainable routes for the synthesis of NIPUs reported in the literature are presented in the following article. [ABSTRACT FROM AUTHOR]

A series of new trichloromethyl- and alkoxy-substituted pyrido[2,3-d]pyrimidine derivatives were obtained from trichloromethyl-substituted pyrimidines with vicinal amino and acyl groups synthesized based on the reaction of trichloroacetonitrile with β-diketone diaminomethylidene derivatives. [ABSTRACT FROM AUTHOR]

Structural modification of 3,4-dihydro-nor-isoharmine through expansion of the dihydropyridine ring to dihydroazepine was accomplished in two stages including pyridine-azepine recyclization of the quaternized substrate by the action of phenacyl halides and their heterocyclic analogs. The recyclization process can be accompanied by 1,2-migration of the acyl group to give mixtures of 4-acyl-9-methoxy-3-methyl-1,2-dihydroazepino[4,5-b]indoles and their 5-acyl-substituted isomers. Factor influencing the recyclization direction and product ratio were analyzed. [ABSTRACT FROM AUTHOR]

Key message: This report describes the most extensive known gene discovery study from an oilseed that produces cyclopropane fatty acids, a novel industrial feedstock.Abstract: Nature contains hundreds of examples of plant species that accumulate unusual fatty acids in seed triacylglycerols (TAG). Although lipid metabolic genes have been cloned from several exotic plant species, the underlying mechanisms that control the production of novel TAG species are still poorly understood. One such class of unusual fatty acids contain in-chain cyclopropane or cyclopropene functionalities that confer chemical and physical properties useful in the synthesis of lubricants, cosmetics, dyes, coatings, and other types of valuable industrial feedstocks. These cyclopropyl fatty acids, or CPFAs, are only produced by a small number of plants, primarily in the order Malvidae. Litchi chinensis is one member of this group; its seed oil contains at least 40 mol% CPFAs. Several genes, representing early, middle, and late steps in the Litchi fatty acid and TAG biosynthetic pathways have been cloned and characterized here. The tissue-specific and developmental transcript expression profiles and biochemical characteristics observed indicate which enzymes might play a larger role in Litchi seed TAG biosynthesis and accumulation. These data, therefore, provide insights into which genes likely represent the best targets for either silencing or overexpression, in future metabolic engineering strategies aimed at altering CPFA content. [ABSTRACT FROM AUTHOR]

Benzoate (found in milk and widely used as preservative), salicylate (present in fruits and the active component of aspirin), dietary polyphenols produced by gut microbiota, metabolites from organic acidemias, and medium-chain fatty acids (MCFAs) are all metabolised/detoxified by the glycine conjugation pathway. Xenobiotics are first activated to an acyl-CoA by the mitochondrial xenobiotic/medium-chain fatty acid: CoA ligases (ACSMs) and subsequently conjugated to glycine by glycine N-acyltransferase (GLYAT). The MCFAs are activated to acyl-CoA by the ACSMs before entering mitochondrial β-oxidation. This two-step enzymatic pathway has, however, not been thoroughly investigated and the biggest gap in the literature remains the fact that studies continuously characterise the pathway as a one-step reaction. There are no studies available on the interaction/competition of the various substrates involved in the pathway, whilst very little research has been done on the ACSM ligases. To identify variants/haplotypes that should be characterised in future detoxification association studies, this study assessed the naturally observed sequence diversity and protein expression variation of ACSM2A and ACSM2B. The allelic variation, haplotype diversity, Tajima’s D values, and phylogenetic analyses indicated that ACSM2A and ACSM2B are highly conserved. This confirmed an earlier hypothesis that the glycine conjugation pathway is highly conserved and essential for life as it maintains the CoA and glycine homeostasis in the liver mitochondria. The protein expression analyses showed that ACSM2A is the predominant transcript in liver. Future studies should investigate the effect of the variants identified in this study on the substrate specificity of these proteins. [ABSTRACT FROM AUTHOR]

Stereoselective synthesis of α-sialosides by the glycosylation reaction (sialylation) is an important task in carbohydrate chemistry. Using quantum chemical calculations, the conformations of the sialyl cation formed from the sialyl donor under conditions of sialylation reaction were studied. Although the "axial conformation" of sialyl cation itself is energetically unfavorable, it is possible to stabilize it through the participation of O- and N-acyl protective groups. The obtained results open the possibility to modulate the stereoselectivity of sialylation by directed variation of the nature of protective groups in the sialyl donor molecule. 2 [ABSTRACT FROM AUTHOR]

2-Aminocarboxylic acids have been synthesized through the reaction of lithium acylate α-carbanions with alkyl nitrites to form α-hydroxyiminoacylates, followed by reduction of the latter with tin chloride. The reactions of lithium acylate α-carbanions, generated by the metalation of carboxylic acids with lithium diisopropylamide at 35-40°С in THF under argon, with alkyl nitrites at 45-50°С give 2-hydroxyiminocarboxylic acids in 55-97% yields. The reduction of 2-hydroxyiminocarboxylic acids with tin(II) chloride in conc. HCl at 20-25°С leads to 2-aminocarboxylic acid hydrochlorides in 52-94% yields. [ABSTRACT FROM AUTHOR]

The rate at which phospholipids equilibrate between different membranes and between the non-polar environments in biological fluids is of high importance in the understanding of biomembrane diversity, as well as in the development of liposomes for drug delivery. In this work, we characterize the rate of insertion into and desorption from POPC bilayers for a homologous series of amphiphiles with the fluorescent NBD group attached to phosphoethanolamines of different acyl chain lengths, NBD-diC n -PE with n = 6, 8, 10, and 12. The rate of translocation between bilayer leaflets was also characterized, providing all the relevant parameters for their interaction with lipid bilayers. The results are complemented with data for NBD-diC14-PE obtained from literature (Abreu et al. Biophys J 87:353-365, 2004; Moreno et al. Biophys J 91:873-881, 2006). The rate of translocation between the POPC leaflets is not dependent on the length of the acyl chains, while this affects strongly the rate of desorption from the bilayer. Insertion in the POPC bilayer is not diffusion controlled showing a significant dependence on the acyl chain length and on temperature. The results obtained are compared with those previously reported for NBD-LysoC14-PE (Sampaio et al. Biophys J 88:4064-4071, 2005), and with the homologous series of single chain amphiphiles NBD-C n (Cardoso et al. J Phys Chem B 114:16337-16346, 2010; J Phys Chem B 115:10098-10108, 2011). This allows the establishment of important relations between the rate constants for interaction with the lipid bilayers and the structural properties of the amphiphiles, namely the total surface and the cross-section of their non-polar region. [ABSTRACT FROM AUTHOR]

1-(Acyl /aroyl)-3-(substituted)thioureas are privileged architectures that have received remarkable attention of researchers in view of their variable topological aspects, binding modes and broad spectrum promising pharmacological properties. Reactivity of acyl thiourea derivatives has presented various organic transformations into other demanding scaffolds and this is an attractive strategy for synthetic chemists to access heterocyclic cores. Multiple binding sites make them flexible ligands for complexation with transition metals thus occupying a distinct position in coordination chemistry. 1-(Acyl /aroyl)-3-(substituted)thioureas have also emerged as attractive candidates in various fields such as ion sensors, corrosion inhibitors, molecular electronics, in metal extraction and in pharmaceuticals. The medicinal chemistry of this organo-sulfur framework and the derived metal complexes has witnessed fantastic progress in the current era. In continuation of our efforts to compile data on the structural aspects and numerous applications of 1-(acyl /aroyl)-3-(substituted)thiourea analogs, continuous advances have prompted us to present an overview of the last 2 years literature on this exciting family of compounds through this review article. [ABSTRACT FROM AUTHOR]

A two-step method, i.e., the transfer acyl analysis and then the chiral HPLC analysis, was employed in the screening of the cosmid library of Microbacterium hydrocarbonoxydans genome. Two enantiocomplementary γ-lactamase clones were found. A 40-kb cosmid showed (−)-γ-lactamase activity, and the activity was from Mhg which was reported previously according to the results of PCR identifying experiment. The 37-kb (+)-γ-lactamase cosmid was further constructed into a pUC18 plasmid library and screened by the same two-step method. A plasmid clone harboring a 1.6-kb fragment showed (+)-γ-lactamase activity. A 555-bp ORF in the 1.6-kb fragment showed high (+)-γ-lactamase activity when it was expressed under the control of T promoter. The coding protein showed significant homology with bacterial isochorismatase. The (+)-γ-lactamase was characterized and compared with the (−)-γ-lactamase Mhg. This is another report that two enantiocomplementary γ-lactamases are present in the same strain. [ABSTRACT FROM AUTHOR]

Structural parameters of trans- and cis-isomers of an acryloyl fluoride molecule in the ground ( S) and excited ( S) electronic states are determined. The F(φ) function is expanded into the Fourier series. The internal rotation potential functions (IRPFs) of acryloyl fluoride in both electronic states are derived. To this end, torsional vibrational transition frequencies of both isomers of this molecule were used, which were obtained from the analysis of the vibrational structure Щf a high resolution UV spectrum of acryloyl fluoride vapor with regard to the geometry and energy difference (Δ H) of the isomers. The IRPF parameters V of this molecule in the ( S) state, which were derived based on the transition frequencies of torsional vibrations from the vibrational structure of the high resolution UV spectrum and the IR Fourier spectrum coincided. [ABSTRACT FROM AUTHOR]

Acylsugars are secondary metabolites with proven insect resistance properties that are produced by many Solanaceous species including Solanum pennellii, a wild relative of tomato. The acylsugar chemotypes of S. pennellii varies greatly within its natural range and might be the product of plant/insect coevolution. The S. pennellii accession LA716 was used to transfer increased levels of acylsugar production into the cultivated tomato, resulting in the acylsugar tomato breeding line CU071026. S. pennellii accession LA716 produces high levels of acylsugars with chemotypes that differ greatly from those produced by CU071026 or the trace acylsugars of cultivated tomato. Understanding the genetic regulation of acylsugar chemistry will aid efforts to breed acylsugar production into cultivated tomato, allowing for alteration of both acylsugar base moieties and fatty acid profiles. This study uses a BC1F1 population produced from the cross of S. pennellii LA716 and CU071026 with CU071026 as the recurrent parent to identify QTL that change the fatty acid profile of acylsugars. Multiple QTL and epistatic interactions between QTL were detected including three QTL on chromosomes 2, 5, and 7, which significantly alter the percentage of extended iso-odd branched fatty acids and straight chain fatty acids on the acylsugars. We also report the introgression of one of these QTL, FA 2, into CU071026, resulting in a new tomato line with significantly increased i11:0 as a percentage of the fatty acids in its acylsugars. Candidate genes for these QTL and the impacts of altering acylsugar fatty acid are discussed. [ABSTRACT FROM AUTHOR]

Bacterial multiresistance is a health problem worldwide that demands new antimicrobials for treating bacterial-related infections. In this study, we evaluated the antimicrobial activity and the theoretical toxicology profile of N-substituted-phenylamino-5-methyl-1 H-1,2,3-triazole-4-carbohydrazide derivatives against gram-positive and gram-negative bacteria clinical strains. On that purpose we determined the minimum inhibitory (MIC) and bactericidal (MBC) concentrations, the in vitro cytotoxicity, and in silico risk profiles, also comparing with antimicrobial agents of clinical use. Among the 16 derivatives analyzed, four nitrofurans (N-H-FUR-NO, N-Br-FUR-NO, N-F-FUR-NO, N-Cl-FUR-NO) showed promising MIC and MBC values (MIC = MBC = 1-16 μg/mL). The experimental data revealed the potential of these derivatives, which were comparable to the current antimicrobials with similar bactericidal and bacteriostatic profiles. Therefore, these molecules may be feasible options to be explored for treating infections caused by multiresistant strains. Our in vitro and in silico toxicity reinforced these results as these derivatives presented low cytotoxicity against human macrophages and low theoretical risk profile for irritant and reproductive effects compared to the current antimicrobials ( e.g., vancomycin and ciprofloxacin). The molecular modeling analysis also revealed positive values for their theoretical druglikeness and drugscore. The presence of a 5-nitro-2-furfur-2-yl group seems to be essential for the antimicrobial activity, which pointed these acylhydrazone derivatives as promising for designing more potent and safer compounds. [ABSTRACT FROM AUTHOR]

Also, some of the isolates from leaves of I Cercidiphyllum japonicum i have contained maltol, maltol glucoside [[5]], and cercidin, which has a benzodioxane ring [[6]]. A portion of the EtOAc fraction (6.3 g) was chromatographed on a Sephadex LH-20 column by elution with MeOH-H SB 2 sb O (1:1), affording 13 fractions. Fraction 6 gave compound B 6 b (47 mg) upon washing with MeOH, and fraction 8 was rechromatographed with MeOH-H SB 2 sb O (3:1) to give compound B 8 b (192 mg). Finally, fractions 14 and 15 were repurified with MeOH-H SB 2 sb O (9:1) to afford compound B 7 b (83 mg). [Extracted from the article]

Fagonia indica is a widely known medicinal plant. The extracts of Fagonia species contain secondary metabolites such as flavonoids, phenolic compounds, and terpenoids. Silver nanoparticles are known for antibacterial properties. In this study, AgNPs were synthesized using the callus extract of F. indica as a reducing agent. Characterization through different techniques suggests that the AgNPs absorbed light and gave SPR peaks at 414 nm while in case of ciprofloxacin supplemented callus mediated AgNPs the peak were recorded at 419 nm. Furthermore, FTIR analysis revealed the role of amides, acyl group, nitro group of callus extract of F. indica, and some functional groups of the ciprofloxacin in the reduction process as well as the capping and stabilization of AgNPs. Similarly, X-Ray Diffraction analysis indicate the structure of AgNPs as face-centered cubic crystalline particles. The antibacterial activity of AgNPs and ciprofloxacin and callus extract as control against resistant bacteria such as Escherichia coli, Citrobacter amalonaticus, Shigella sonnei, and Salmonella typhi was studied. The combination of AgNPs and antibiotic showed better antibacterial activity as compared to AgNPs alone and ciprofloxacin alone. Maximum inhibition zone of E. coli, C. amalonaticus, S. sonnei, and S. typhi in response to AgNPs and ciprofloxacin was 38.5 mm, 35.5 mm, 33 mm, and 35.5 mm, respectively. It can, therefore, be suggested that the AgNPs along with Ciprofloxacin might have worked in interaction and resulted in better antibacterial activity against all the tested pathogens. [ABSTRACT FROM AUTHOR]