title: Effect of stereochemistry of avermectin-like 6,6-spiroketals on biological activities and endogenous biotransformations in Streptomyces avermectinius.
abstract: Natural avermectins (AVEs) share a 6,6-spiroketal moiety with an exclusive R configuration at the C21 spirocyclic junction. Herein, we report the characterization of nine AVE-like spiroketals of two types (C21 S and R) in a mutant strain that lacks spirocyclase activity. Comparative analysis of their structures facilitated evaluation of the effect of stereochemistry on endogenous biotransformations and biological activities of the spiroketals.
authors.affiliation: Research Center for Marine Drugs, School of Pharmacy, Second Military Medical University, 325 Guo-He Road, 200433 Shanghai (China); Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, 200032 Shanghai (China).
authors.forename: Peng
authors.initials: P
authors.lastname: Sun
authors.forename: Qunfei
authors.initials: Q
authors.lastname: Zhao
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.forename: Jiequn
authors.initials: J
authors.lastname: Wu
authors.forename: Wen
authors.initials: W
authors.lastname: Liu
mesh_terms: D001711:Biotransformation; D005663:Furans / Q000737:chemistry / Q000378:metabolism*; D007559:Ivermectin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D013141:Spiro Compounds / Q000737:chemistry / Q000378:metabolism*; D013237:Stereoisomerism; D013302:Streptomyces / Q000737:chemistry / Q000378:metabolism*
chemical_list: D005663:Furans; D013141:Spiro Compounds; C520774:spiroketal; D007559:Ivermectin; C019264:avermectin
keywords: avermectins; biosynthesis; endogenous biotransformation; spiro compounds; spiroketals