Pigments of aminophenoxazinones and viridomycins produced by termite-associated BYF-112.

Termite-associated BYF-112 was found as a potential source for yellow and green pigments, which were stable under the tested temperature, light and metal ions. Eight metabolites (-), including four new natural yellow pigments aminophenoxazinones (-), and two rarely iron dependent green pigments viridomycin A and F (-) were isolated from BYF-112 cultured in YMS and YMS treated with FeSO, respectively. The metabolites - displayed a significant safety performance on the normal liver cell line L-02, while the metabolite showed weak cytotoxicity against the L-02 and several cancer cells. Especially, in the filter paper disc tests, the compound possessed strong antibacterial activity against methicillin-resistant (MRSA) with the zone of inhibition (ZOI) of 15.3 mm, which was equal to that of referenced levofloxacin (ZOI = 15.2 mm). And the metabolite also showed moderate antibacterial activities against and , with the ZOI values of 15.3 and 17.2 mm. In addition, by the minimum inhibitory concentration (MIC) assay, the compound 1 displayed potential antibacterial activities against , and MRSA, with the MIC values of 12.5, 12.5, and 25.0 μg/ml, respectively. The present results indicate that BYF-112 may be a promising source for safe and bioactive pigments, which can be used for further development and industrial applications.