ABSTRACT
Actinomycin Z6 (1), a new member of the actinomycin family, along with three congeners of the Z-type (Z1, Z3, Z5) actinomycins, are produced from Streptomyces sp. KIB-H714. Their structures were authenticated by comprehensive spectroscopic data interpretation. Different from all the reported Z-type actinomycins, the ß-ring of the new compound actinomycin Z6 includes an additional ring linked between the actinoyl chromophore and ß-peptidolactone. In Z3 and Z5, the L-threonine in ß-depsipeptide is replaced by the unusual 4-chlorothreonine, an amino acid rarely found in actinomycin family. All isolates were evaluated for cytotoxicity against five human tumor cell lines and for inhibitory activity against Candida albicans and Staphylococcus aureus.
Subject(s)
Anti-Infective Agents/pharmacology , Antineoplastic Agents/pharmacology , Dactinomycin/analogs & derivatives , Dactinomycin/pharmacology , Streptomyces/chemistry , Anti-Infective Agents/chemistry , Antineoplastic Agents/chemistry , Candida albicans/drug effects , Cell Line, Tumor , Dactinomycin/chemistry , Drug Evaluation, Preclinical/methods , Humans , Magnetic Resonance Spectroscopy , Molecular Structure , Oxygen/chemistry , Spectrometry, Mass, Electrospray Ionization , Staphylococcus aureus/drug effects , Structure-Activity Relationship , Threonine/analogs & derivatives , Threonine/chemistryABSTRACT
Constituents of the fruits of Peatasites tatewakianus were investigated. A new compound, namely bakkenolide-VI (1), was isolated. The structures was elucidated on the basis of 1D, 2D NMR, TOF-MS and ESI-MS techniques, and physicochemical properties. The neuroprotective activity of the new compound was assayed with primary cultured neurons exposed to oxygen-glucose deprivation and oxidative insults.