Background: To evaluate the antimicrobial and microbicidel activity of B. radicata fermentation broth, the broth was purified by DEAE-cellulose and sephadex LC-20 column. The compounds were submitted to spectral analyses (HPLC, FT-IR, 1D and 2D NMR etc.).
Results: The purified compounds were identified as the Griseococcin(s) which were naphthoquinone derivatives, the Chemical formula and MW of Griseococcin (1) was determined as C37O10H43N and 661 Da. only Griseococcin (1) has good antimicrobial activity among the Griseococcin(s). The zone of inhibition (ZOI), minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) or minimum fungicidal concentration (MFC) of Griseococcin (1) were used to investigate the antimicrobial activity. Antifungal activity of Griseococcin (1) was significant, especially for main pathogenic fungus Trichophyton rubrum and Trichophyton mentagrophytes, MFC/MIC of Griseococcin (1) was 1, while MFC/MIC of postive control was greater than 4, the fungicidal effect of Griseococcin (1) was better than that of positive control.
Conclusions: In this paper, the secondary metabolite compound Griseococcin (1) from B. radicata was purified. The purified compound can restrain main pathogens (T. rubrum and T. mentagrophytes) leading to tinea pedis. The antifungal activity of Griseococcin (1) was similar to that of the positive control and the fungicidal effect of Griseococcin (1) was better than that of positive control, it might be suitable for pharmaceutical industries.
Keywords: 1D NMR; 2D NMR; DEAE; FT-IR; Griseococcin; HPLC; LH-20.