ABSTRACT
In an analytical study of microbial broths, the actinomycete strain Kitasatospora sp. P07101 was found to produce three new congeners, which were designated hazimycins B (1), C (2), and D (3), together with the previously reported hazimycin (renamed hazimycin A (4)). The structures of these hazimycins were examined using various spectroscopic methods including nuclear magnetic resonance (NMR), and the results revealed that 1-3 were analogues of hazimycin with the replacement of one of the two isonitrile groups in 4 by an NH-formyl group in 1, the two isonitrile groups and an amide group by two NH-formyl groups and a nitrile group in 2, and the two isonitrile groups and two amide groups by two NH-formyl groups and two nitrile groups in 3. Only hazimycin A exhibited moderate antimicrobial activities against Gram-positive bacteria and Candida albicans. These results indicated that the presence of two isonitrile groups in the hazimycin structure is essential for antimicrobial activity.
ABSTRACT
A simple and sensitive method was developed to screen ?-PL p ro duced strains from soils. 150mg/L K_2Cr_2O_7 was added to th e solid medium for actinomycetes enriching. A basic dye, methylene blue, incorp orated in the agar plate to detect alkali producers, because dye reacted with th e secreted basic polymers by electrostatic interaction with the secreted basic p dymers and formed special zoon. And then dragendorff regent was used to detect alkaloid producers. Four ?-PL producers were obtained by TLC analysis. Meanw hile, phylogenetic analysis of PL6-3 strain, including morphology, physiologica l and biochemical characters and chemotaxomy were performed and phylogenetic tre e was constructed based on the 16S rDNA sequences. And the results indicated th at PL6-3 strain is a member of Kitasatospora.