Chaetoglobosin U, a cytochalasan alkaloid from endophytic Chaetomium globosum IFB-E019.
A new cytotoxic cytochalasan-based alkaloid named chaetoglobosin U (1), along with four known analogues, chaetoglobosins C (2), F (3), and E (5) and penochalasin A (4), has been characterized from the EtOAc extract of a solid culture of Chaetomium globosum IFB-E019, an endophytic fungus residing inside the stem of healthy Imperata cylindrica. The structure of chaetoglobosin U was determined through correlative analyses of its UV, IR, CD, MS, and 1D ((1)H and(13)C NMR and DEPT) and 2D NMR (COSY, NOESY, HMQC, and HMBC) data. Chaetoglobosin U (1) exhibited cytotoxic activity against the human nasopharyngeal epidermoid tumor KB cell line with an IC(50) value of 16.0 microM, comparable to that (14.0 microM) of 5-fluorouracil co-assayed as a positive reference. The known analogues 2-5 were moderately active to the cell line, with IC(50) values of 34.0, 52.0, 48.0, and 40.0 microM, respectively.
Ding
Gang
G
Institute of Functional Biomolecules, State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210093, People's Republic of China.
Song
Yong C
YC
Chen
Jing R
JR
Xu
Chen
C
Ge
Hui M
HM
Wang
Xiao T
XT
Tan
Ren X
RX
D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D002597:Chaetomium / Q000737:chemistry*; D002681:China; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D026121:Indole Alkaloids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D007624:KB Cells; D015394:Molecular Structure
D000970:Antineoplastic Agents; D026121:Indole Alkaloids; C019290:chaetoglobosins