Study On The Active Metabolites Screening From The Marine Fungus10010A Of East China Sea By LC-UV

The marine fungus100101A was isolated from East China Sea.seawater sample and was characterized as a Rhodotorula minuta species on the basis of its18S rRNA gene sequence, morphology and physiology.The crude extracts (68g) were extracted3times with n-BuOH from the70L fermentation broth of R. minuta. The highly polar extracts were showed significative activities of antioxidan (DPPH method) and antitumor in vitro (MTT method) detected by HPLC-UV model. The A、B、C、D and E fractions were isolated using reversed phase ODS column in order of elution according to the retention time on the basis of HPLC-UV model. And A、B and C fractions were showed good activities of antioxidan and antitumor in vitro. The15compounds were isolated from the A、B and C fractions by preparative HPLC. The structures of9compounds were identificated by the spectroscopic and chemical analysis as cyclo (Leu-Ile)(1), cyclo (Gly-Pro)(2), cyclo (Ala-Pro)(3), cyclo (Pro-Pro)(4), cyclo (Pro-Val)(5), cyclo (Ala-Val)(6), cyclo (Val-Ile)(7),(22E,24R)-ergosta-7,22-dien-3β,5a,6p-triol)(8) and adenosine (9).All isolated compounds were evaluated for antioxidan and antitumor activities. The result show that the DPPH scavenging ratio of compund1was more than73.76%when its concentration was100μg-mL-1, its IC50against HepG2, PC-12and U937were0.538,0.635and0.437μmol-mL-1, respectively. Also, compund1can induce the U937cells to apoptosis effectively based on Flow Cytometry (FCM) data. The compund2showed medium DPPH scavenging ratio with46.58%at the concentration of100μg-mL-1and lower antitumor activtity against HepG2, MCF-7and U937with IC50of1.683,2.392andl.571μmol·mL-1, respectively. The compund8showed unsatisfactory DPPH scavenging activtity at the concentration of100μg-mL-1and strong activities against U937、HepG2、Hela with antineoplastic ratio of72.02%、50.19%、41.26%, respectively. Others compounds are only displayed weak activity in the experiment.The compounds1-9were isolated for the first time from marine fungus R. minuta. The antitumor mechanism of compound1and cytotoxicity of compound8were reported for the first time. These results laid the foundation for future research on the bioactivity secondary metabolities of marine fungus R. minuta and enrichment for marine natural products reseach.