ABSTRACT
Four previously undescribed angucyclinones umezawaones A-D (1-4) were isolated from the liquid cultures of Umezawaea beigongshangensis. Their structures were determined by spectroscopic analyses, single crystal X-ray diffraction, quantum chemical 13C NMR and electronic circular dichroism calculations. All compounds displayed strong inhibitory activities against indoleamine 2,3-dioxygenase and tryptophan-2,3-dioxygenase in enzymatic assay, especially compound 2.
Subject(s)
Actinobacteria , Tryptophan Oxygenase , Tryptophan Oxygenase/chemistry , Tryptophan Oxygenase/metabolism , Angucyclines and Angucyclinones , Actinomyces/metabolism , Indoleamine-Pyrrole 2,3,-Dioxygenase , Molecular StructureABSTRACT
Cangumycins A-F (1-6), six new angucyclinone analogues, together with two known ones (7 and 8), were isolated from the fermentation broth of a soil-derived Streptomyces sp. KIB-M10. Structures of these compounds were elucidated via a joint use of spectroscopic analyses and single-crystal X-ray diffractions. Among them, cangumycins E (5) and F (6) share a C-ring cleaved backbone, and cangumycins B (2) and E (5) exhibit potent immunosuppressive activity (IC50 8.1 and 2.7 µmol·L-1, respectively) against human T cell proliferation at a non-cytotoxic concentration.