ABSTRACT
A novel promising strain of actinobacteria Rhodococcus sp. 77-32 was identified. Its acetonetreated biomass the could be used as a biocatalyst for production of S-(-)-2-[6-benzyloxy-2,5,7,8-tetramethylchroman-2-yl] ethanol (S-BCE), a precursor of natural α-tocols. It was established that a reaction of enantioselective hydrolysis of racemic (±)-2-(2-acetoxyethyl)-6-benzyloxy-2,5,7,8-tetramethylchroman (BCEA) occurred in the phosphate bufferacetone system, resulting in enrichment of the residual substrate by S-enantiomer (S-(+)-2-(2-acetoxyethyl)-6-benzyloxy-2,5,7,8-tetramethylchroman, S-BCEA). It was shown that the hydrolysis was accompanied by stereoinversion of the formed product, R-(+)-2-[6-benzyloxy-2,5,7,8-tetramethylchroman-2-yl] ethanol (R-BCE), into the S-BCE. The transformation conditions (acetone content, acidity, temperature, reaction duration) were optimized, providing simultaneous production of optically pure S-BCE and S-BCEA with an almost quantitative yield.
Subject(s)
Chromans/chemical synthesis , Rhodococcus/chemistry , Tocopherols/chemical synthesis , Acetone/chemistry , Biocatalysis , Biomass , Chromans/isolation & purification , Hydrogen-Ion Concentration , Hydrolysis , Solvents/chemistry , Stereoisomerism , Temperature , Tocopherols/isolation & purificationABSTRACT
The long-term stress protective effects have been revealed among newly synthesized 9α-hydroxy-5α-ecdysteroids via a short-term heat stress tests (housefly Musca domestica). An increase as well as a reduce of protective effects for synthesized compounds have been demonstrated in comparison with the reference ecdysteroid 20-hydroxyecdysone, which obtained from the juice of Serratula coronata. The interdependence between stress- and geroprotective properties of the test models with their genotypic features and the structure of ecdvsteroids has been established.
Subject(s)
Aging/drug effects , Ecdysterone/pharmacology , Heat Stress Disorders/prevention & control , Animals , Disease Models, Animal , HousefliesABSTRACT
The oxidation of primary hydroxyl groups in dermatan sulfate with the NaOCl-NaBr-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) reagent in an aqueous alkaline environment was carried out for the first time. Modified dermatan sulfates containing hydrated aldehyde (15-50%) and carboxyl (25-100%) groups were obtained.
Subject(s)
Bromides/chemistry , Cyclic N-Oxides/chemistry , Dermatan Sulfate/analogs & derivatives , Dermatan Sulfate/chemistry , Sodium Compounds/chemistry , Sodium Hypochlorite/chemistry , Oxidation-Reduction , WaterABSTRACT
Conjugation of chondroitin sulfates with pharmacologically important amines in a water medium in the presence of 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide was studied. Conjugates with amide and isoureidocarbonyl groups were synthesized.
Subject(s)
Amines/chemistry , Chondroitin Sulfates/chemistry , Ethyldimethylaminopropyl Carbodiimide/chemistryABSTRACT
The modem state of chemical modification of hyaluronic acid, chondroitin sulfates, and heparin is considered, and the possible application of modified glycosaminoglycans as potential drugs is discussed.
Subject(s)
Glycosaminoglycans/chemistryABSTRACT
Information on the synthesis and biological activity of natural and synthetic analogues of alpha-tocopherol with a modified side chain is systematized. These compounds are of interest as vitamin E metabolites, hydrophilic antioxidants, and precursors of drugs with combined pharmacological properties useful in therapy of pathological disorders caused by oxidative stress.
Subject(s)
Antioxidants , alpha-Tocopherol , Animals , Antioxidants/chemical synthesis , Antioxidants/chemistry , Antioxidants/pharmacology , Humans , Molecular Structure , Oxidative Stress/drug effects , Stereoisomerism , Structure-Activity Relationship , alpha-Tocopherol/analogs & derivatives , alpha-Tocopherol/chemical synthesis , alpha-Tocopherol/pharmacologyABSTRACT
Hyaluronic acid was modified with aromatic amino acids (5-aminosalicylic, 4-aminosalicylic, anthranilic, and p-aminobenzoic) in the presence of 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide. The modified glycans contained 9-43% of arylamide groups and 10-33% of isoureidocarbonyl groups depending on the nature of the amino acid. Reduction with sodium borohydride allowed the conversion of isoureidocarbonyl groups into hydroxymethyl groups.
Subject(s)
Amino Acids, Aromatic/chemistry , Carbodiimides/chemistry , Hyaluronic Acid/chemistry , Humans , Hyaluronic Acid/isolation & purificationABSTRACT
Seven phytoecdysteroids have been isolated from Serratula coronata L. One of them is a new phytoecdysteroid, 3-epi-20-hydroxyecdysone. Two further ecdysteroids, 20-hydroxyecdysone 22-acetate and taxisterone, are isolated from this species for the first time in addition to the typical S. coronata ecdysteroids, 20-hydroxyecdysone, ecdysone, ajugasterone C and polypodine B. The juice squeezed from aerial parts of fresh plants of S. coronata was extracted with ethyl acetate. The ecdysteroids were isolated by a combination of chromatographic techniques (mainly HPLC) and identified by 1D and 2D (1)H and (13)C NMR experiments and mass-spectrometry. The biological activities of 3-epi-20-hydroxyecdysone (EC(50)=1.6 x 10(-7) M), taxisterone (EC(50)=9.5 x 10(-8) M) and ajugasterone C (EC(50)=6.2 x 10(-8) M) have been determined in the Drosophila melanogaster B(II) bioassay for ecdysteroid agonist activity.