Metabolomics revealed novel isoflavones and optimal cultivation time of Cordyceps militaris fermentation.
Germinated soybean (GS) cultivated with Cordyceps militaris (GSC) might be a promising efficacious source of novel bioactive compounds. In this study, the metabolome changes between GS and GSC were investigated by liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) analysis coupled with a multivariate data set. Principal component analysis (PCA) and orthogonal projection to latent structures discriminate analysis (OPLS-DA) of GSC clearly showed higher levels of soyasaponin Bd, soyasaponin Bc(II), daidzein, genistein, four isoflavones (compounds 1-4), glycerol, proline, glutamine, pentitol, fructose, inositol, octadecanoic acid, and sucrose together with lower levels of pyroglutamic acid, citric acid, histidine, and palmitic acid in GSC than in GS. The structures of compounds 1-4 were analyzed by mass and NMR spectroscopy and were determined to be novel isoflavone methyl-glycosides (daidzein 7-O-beta-d-glucoside 4''-O-methylate (1), glycitein 7-O-beta-d-glucoside 4''-O-methylate (2), genistein 7-O-beta-d-glucoside 4''-O-methylate (3), and genistein 4'-O-beta-d-glucoside 4''-O-methylate (4)). Multivariate statistical models showed that metabolic changes of GSC were maximal within 1 week after the C. militaris inoculation, consistent with the strongest antioxidant activity of GSC cultivated for 1 week. This metabolomics study provides valuable information in regard to optimizing the cultivation process for bioactive compound production and describes an efficient way to screen for novel bioactive compounds from GSC.
Choi
Jung Nam
JN
Department of Bioscience and Biotechnology and Bio/Molecular Informatics Center, Konkuk University, Seoul, Republic of Korea.
Kim
Jiyoung
J
Lee
Mi Yeon
MY
Park
Dong Ki
DK
Hong
Young-Shick
YS
Lee
Choong Hwan
CH
D002851:Chromatography, High Pressure Liquid; D032661:Cordyceps / Q000737:chemistry / Q000378:metabolism*; D046508:Culture Techniques; D005285:Fermentation; D008401:Gas Chromatography-Mass Spectrometry; D007529:Isoflavones / Q000032:analysis* / Q000378:metabolism; D055432:Metabolomics; D045730:Soy Foods / Q000032:analysis* / Q000382:microbiology
D007529:Isoflavones