2990-25-2Relevant academic research and scientific papers
Empirical rules for the enantiopreference of lipase from Aspergillus niger toward secondary alcohols and carboxylic acids, especially α-amino acids
Janes, Lana E.,Kazlauskas, Romas J.
, p. 3719 - 3733 (1997)
Lipase from Aspergillus niger (ANL, Amano lipase AP) catalyzes enantioselective hydrolysis and acylation reactions. To aid in the design of new applications of this lipase, we propose two empirical rules that predict which enantiomer reacts faster. For secondary alcohols, a rule proposed previously for other lipases also works for ANL, but with lower reliability (77%, 37 of 48 examples). For carboxylic acids, we examined both crude and partially-purified ANL because commercial ANL contains contaminating hydrolases. Partial purification removed a contaminating amidase and increased the enantioselectivity of ANL toward many α-amino acids, including cyclic amino acids. Unlike other lipases, ANL readily accepts positively-charged substrates and shows the highest enantioselectivity towards α-amino acids. Although a rule based on the sizes of the substituents could not predict the fast-reacting enantiomer, a rule limited to α-amino acids did predict the fast-reacting enantiomer. We estimate that the charged α-amino group contributes a factor of 40-100 (ΔΔ≠ = 2.2-2.7 kcal/mol) to the enantioselectivity of ANL towards carboxylic acids.
Tumescenamide C, an antimicrobial cyclic lipodepsipeptide from Streptomyces sp.
Kishimoto, Shinji,Tsunematsu, Yuta,Nishimura, Shinichi,Hayashi, Yutaka,Hattori, Akira,Kakeya, Hideaki
experimental part, p. 5572 - 5578 (2012/09/08)
Tumescenamide C, a new cyclic lipodepsipeptide, was isolated from a culture broth of an actinomycete Streptomyces sp. KUSC-F05. Tumescenamide C was a congener of tumescenamides A and B, representing a sixteen-membered ring system, consisting of two proteinogenic and three non-proteinogenic amino acids, to which a methyl-branched fatty acid was attached. The planar structure was determined by spectroscopic analysis, while its absolute stereochemistry was determined by chemical degradation and asymmetric synthesis. Tumescenamide C exhibited antimicrobial activity with high selectivity against Streptomyces species.
