Active Amino Alcohols Research Articles

Isolation and sequence determination of trichorzianines A antifungal peptides from Trichoderma harzianum.

Trichorzianines A, membrane active peptides of the peptaibol class, were isolated from cultures of the mould Trichoderma harzianum. Trichorzianines A were separated into pure components by HPLC on octadecyl bonded and SiO2 phases successively. Nine trichorzianines A (IIa, IIIa, IIIb, IIIc, IVb, Vb, VIa, VIb and VII) were isolated from the complex microheterogeneous mixture. Their N-terminal amino acid is acetylated, the C-terminal amino alcohol is either tryptophanol or phenylalaninol, 7 to 8 of the 19 residues are alpha-aminoisobutyric acid. Gas chromatography on a chiral phase showed isovaline to have the D-configuration and all the other optically active amino acids and amino alcohols to have the L-configuration. The amino acid sequences were determined from their positive ion FAB mass spectra which exhibited the preferential cleavage of the Aib 12-Pro 13 amide bond as a main fragmentation. The resulting fragments subsequently underwent amide bond ruptures that generated two series of abundant acylium ions which enabled direct determination of the 1-19 sequence. The relative position of the isomeric amino acids in the sequence of trichorzianine AVII was assigned from analysis of the N- and C-terminal oligopeptides yielded by its selective acidic hydrolysis. The microheterogeneity of trichorzianines A results mainly from single or multiple substitution of amino acids at the specific positions 5, 14, 16 and 19.

Catalytic Behavior of Optically Active Amino Alcohol–Borane Complex in the Enantioselective Reduction of Acetophenone Oxime O-Alkyl Ethers

Abstract In the presence of the optically active amino alcohol–borane complex, an oxime ether was reduced with various hydride reducing agents to give a chiral primary amine of high optical purity. Catalytic use of the chiral complex was also investigated.

光学活性アミノアルコール・ボラン錯体による触媒的不斉還元

Reaction of optically active amino alcohol with 2 equiv. of BH3·THF gave the excellent asymmetric reducing agent, which reduced aromatic ketones, dialkylketones, and oxime ethers to yield chiral secondary alcohols and primary amines, respectively, with high optical yield (>90%ee). Optically active amino alcohols were easily prepared from amino acids. Cross-linked polystyrene supported chiral amino alcohols were also prepared. A polymeric asymmetric reducing agent could realize high enantioselectivity as same as monomeric one with quantitative recover and reuse. Catalytic use of the chiral amino alcohol-borane complex was also investigated on the basis of following behaviours. (1) The reduction with borane was accelerated by the presence of the complex. (2) Large amount of the product was obtained by the use of the small amount of the complex. (3) The product is optically active. (4) The product does not bind to the complex.

ChemInform Abstract: OPTICAL RESOLUTION OF 2‐AMINO‐1,2‐DIPHENYLETHANOL BY PREFERENTIAL CRYSTALLIZATION AND ITS UTILIZATION IN FRACTIONAL CRYSTALLIZATION AND ENANTIOSELECTIVE REDUCTION OF PROCHIRAL KETONES

AbstractDie Titelverbindung (I), durch katalytische Reduktion von Benzoinoxim zugänglich, läßt sich durch das Verfahren der bevorzugten Kristallisation in die optisch aktiven Formen trennen.

Optical Resolution of 2-Amino-1,2-diphenylethanol by Preferential Crystallization and Its Utilization in Fractional Crystallization and Enantioselective Reduction of Prochiral Ketones

Abstract (±)-erythro-2-Amino-1,2-diphenylethanol prepared from benzoin oxime by catalytic reduction was successfully resolved into a pair of optically active forms by preferential crystallization. The optically active amino alcohol was found to be useful as a basic resolving agent for the optical resolution of tartaric acid, trans-2,3-oxiranedicarboxylic acid, 2-hydroxy-2-phenylpropionic acid, and 3-endo-benzamido-5-norbornene-2-endo-carboxylic acid. Chiral hydrides prepared from lithium aluminium hydride and optically active threo- or erythro-2-amino-1,2-diphenylethanol derivatives were applied to the enantioface differentiating reduction of prochiral ketones to give the corresponding optically active alcohols in 26–72% optical purities.

Preferential Crystallization of 2-Amino-2-phenylethanol and Its Application as a Resolving Agent

Abstract (±)-2-Amino-2-phenylethanol (phenylglycinol) prepared from (±)-2-amino-2-phenylacetic acid (Dl-phenylglycine) by lithium aluminium hydride reduction was efficiently resolved into a pair of optically active forms by preferential crystallization. The optically active amino alcohol was successfully applied as a basic resolving agent to the resolution of tartaric acid, 2-hydroxy-2-phenylpropionic acid, 2-hydroxy-3-phenylpropionic acid, 2-phenylpropionic acid, and 2-phenyl-2-ureidoacetic acid.

Palladium-promoted asymetric oxyamination of alkenes application to the synthesis of optically active aryloxypropanolamines

Palladium-promoted oxyamination of some alkene using optically active N-methyl-α☎enylethylamine as amine nucleophile, or using optically active N,N-dimethyl-α-phenylethylamine as ligand, produces optically active aminoalcohol derivatives in an optically yield of 3–60%. Oxyamination of aryl ethers gives optically active 1-amino-3-aryloxy-propan-2-ol derivatives, which are important β-blockers.

Analysis of d-ethambutol by circular dichroism of its copper chelates.

Antituberculostatic agent ethambutol, possessing a little molar specific rotation, was converted to several metal chelated derivatives. Among them, the copper chelate showed a large ellipticity value in its circular dichroism (CD) spectrum. A quantitative analysis of ethambutol by means of the copper chelation followed by CD spectroscopic measurements were investigated. Thus, addition of 0.1 ml of 0.3% ethanolic solution of ethambutol to 2.9 ml of 0.01% ethanolic solution of cupric chloride was ready to form copper chelated ethambutol which gave CD ellipticity value 4.6±0.3 in its CD spectrum. The present method is one of the convenient procedures to introduce a chromophoric nature to an optically active amino alcohol for a CD measurement.