Antitumor activity in vitro and volatile components of metabolites from myxobacteria Stigmatella WXNXJ-B

Myxobacteria can generally produce large families of secondary metabolites with various bioactivities, such as antifungal and antitumor activities. In this paper, the metabolites absorbed by the resin, XAD16 from Stigmatella WXNXJ-B exhibited a high level of antitumor activities in vitro. The IC50 values were 14.34, 4.11, 16.36 and 19.46 mu g/ml on mouse melanoma cell lines, murine colon carcinoma cells, human liver carcinoma cells and human breast cancer cells, respectively and the value of IC50 on mouse spleen cells was above 750 mu g/mL. The volatile components of Stigmatella WXNXJ-B were analyzed with gas chromatography-mass spectrometry. The main volatile compound in the fermentation broth consisted of alcohols (24.3%), esters (14.3%), ketones (14.3%), alkyls (10.0%), hetero-cyclic (17.1%), aromatic (5.7%), acids and aldehydes (8.6%) and others (5.7%). Of these, 2,5-dimethylpyrazine,2,3-dimethyl-5-ethyl-pyrazine and 2-ethyl-6-methyl-pyrazine were assessed to be present.