Identification of Strain H41-55 and Chemical Constituents from its Fermentation Broth

The strain H41-55 was identified as Streptomyces antibioticus according to morphological, cultural, and physiological and biochemical characteristics in combination with 16S rDNA sequence and phylogenetic tree analysis of the strain, and the 16S rDNA accession number in Genbank was FJ702547. Five steroid and two actinomycin compounds, named ergosta-7,22-diene-3b,5a,6b-triol (1), ergosta-8 (14),22E-diene-3b,5a,6b,7a-tetraol (2), 3b,5a,9a-trihydroxy-(22E,24R)-ergosta-7,22-diene-6-one (3), ergosta-4,6,8 (14),22-tetraen-3-one (4) and (22E,24R )-ergosta-4,7,22-trien-3-one (5), actinomycin D (6), actinomycin X2 (7), were isolated from the fermentation broth of strain H41-55. The structures of the steroid were determined by spectroscopic methods including NMR and MS as well as comparison with the data of literatures