Preparative Separation of Sulfur-Containing Diketopiperazines from Marine Fungus Cladosporium sp. Using High-Speed Counter-Current Chromatography in Stepwise Elution Mode
Binbin Gu,
Yanying Zhang,
Lijian Ding,
Shan He,
Bin Wu,
Junde Dong,
Peng Zhu,
Juanjuan Chen,
Jinrong Zhang,
Xiaojun Yan
Affiliations
Binbin Gu
School of Marine Sciences, Laboratory of Marine Natural Products, Ningbo University, Ningbo 315211, China
Yanying Zhang
CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
Lijian Ding
College of Pharmacy, Jinan University, Guangzhou 510632, China
Shan He
School of Marine Sciences, Laboratory of Marine Natural Products, Ningbo University, Ningbo 315211, China
Bin Wu
Ocean College, Zhejiang University, Hangzhou 310058, China
Junde Dong
CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
Peng Zhu
Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Ningbo University, Ningbo 315211, China
Juanjuan Chen
School of Marine Sciences, Laboratory of Marine Natural Products, Ningbo University, Ningbo 315211, China
Jinrong Zhang
School of Marine Sciences, Laboratory of Marine Natural Products, Ningbo University, Ningbo 315211, China
Xiaojun Yan
Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Ningbo University, Ningbo 315211, China
High-speed counter-current chromatography (HSCCC) was successively applied to the separation of three sulfur-containing diketopiperazines (DKPs) (including two new compounds cladosporin A (1) and cladosporin B (3), and a known compound haematocin (2)) from a marine fungus Cladosporium sp. The two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water at (1:1:1:1, v/v) and (2:1:2:1, v/v), in stepwise elution mode, was used for HSCCC. The preparative HSCCC separation was performed on 300 mg of crude sample yielding 26.7 mg of compound 3 at a purity of over 95%, 53.6 mg of a mixture of compounds 1 and 2, which was further separated by preparative-HPLC yielding 14.3 mg of compound 1 and 25.4 mg of compound 2 each at a purity of over 95%. Their structures were established by spectroscopic methods. The sulfur-containing DKPs suppressed the proliferation of hepatocellular carcinoma cell line HepG2. The present work represents the first application of HSCCC in the efficient preparation of marine fungal natural products.
