The Secondary Metabolites Study Of Two Marine Actinomycetes Isolated From Jiaozhou Bay

The bioactive metabolites of actinomycetes were studied in this thesis. We collected thesediment samples from Jiaozhou Bay and isolated some actinomycete strains. M045 and M048were screened out by bacteria-inhibition model. On variation of the growth medium, temperature and starting pH, the optimal fermentationcondition of M045 was fish flour medium (FF-medium) with a pH starting at 6.5 and acultivation temperature of 35 °C. The crude extract was obtained from 15 l culture broth. Threepure compounds were isolated by flash chromatography on silica gel, thin layerchromatography and Sephadex LH-20 chromatography. By MS, H-NMR, C-NMR and 2D- 1 13NMR spectra, the structures of the three compounds were determined. Manumycin A (1) 90 mg,chinikomycin A (2) 130 mg and chinikomycin B (3) 10.5 mg belonged to the manumycin group.(2) and (3) were novel compounds. Chinikomycin A (2) and B (3) both exhibited moderateantitumor activity, whereas (2) was shown to be more potent than (3). The hydroquinone (2)selectively inhibited proliferation in cell lines of mammary cancer (MAXF 401NL, IC50 = 2.41μg/ml,), melanoma (MEXF 462NL, IC50 = 4.15 μg/ml), and renal cancer (RXF 944L, IC50 =4.02 μg/ml). The quinone (3) showed selective antitumor activity against the mammary cancercell line MAXF 401NL (IC50 = 3.04 μg/ml). The chinikomycins were inactive against Bacillussubtilis ATCC 6051, Streptomyces viridochromogenes (Tü 57), Staphylococcus aureus, andEscherichia coli, the microalgae Chlorella vulgaris, Chlorella sorokiniana and Scenedesmussubspicatus, the fungus Mucor miehei Tü 284 and Candida albicans. The respective activitiesof the crude extract were due to the manumycin A (1) content. The similar optimization methods, the optimal fermentation condition of M048 was soybean and mannitol medium (SM-medium) with a pH starting at 7.8 and a cultivation iiitemperature of 28 °C. The crude extract was obtained from 25 l culture broth. Ten compoundswere isolated. The seven were known compounds, iodinin (4) 75 mg, 1,6-dihydroxyphenazine(5) 34 mg, genistein (6) 6 mg, daidzein (7) 50 mg, N-acetylquestiomycin A (9) 85 mg,questiomycin A (11) 3 mg and 1,6-diacetylphenazine (13) 26 mg. Chandrananimycin A (10) 6mg, chandrananimycin B (12) 2mg and chandrananimycin C (8) 2 mg were novel compounds.These compounds showed inhibition activity against bacteria, fungi and microalgae. In addition,chandrananimycin A (10), chandrananimycin B (12) and chandrananimycin C (8) exhibitedantitumor activity, IC70 < 1.4 μg/ml. We also identified the strain M045 and M048 by morphological, physiologicalcharacteristics and 16S rDNA analysis. Phylogenetic tree, based on 16S rDNA sequence ofstrain M045 and related taxa, showed that the strain M045 was Streptomyces sp., which washomologous with Streptomyces griseoaurantiacus DSM 40430 . With the similar methods, TM048 was identified as Nocardiopsis dassonvillei.