1. Academic Validation
  2. 1H- and 13C-nmr assignments of phyllanthin and hypophyllanthin: lignans that enhance cytotoxic responses with cultured multidrug-resistant cells

1H- and 13C-nmr assignments of phyllanthin and hypophyllanthin: lignans that enhance cytotoxic responses with cultured multidrug-resistant cells

  • J Nat Prod. 1993 Feb;56(2):233-9. doi: 10.1021/np50092a008.
A Somanabandhu 1 S Nitayangkura C Mahidol S Ruchirawat K Likhitwitayawuid H L Shieh H Chai J M Pezzuto G A Cordell
Affiliations

Affiliation

  • 1 Department of Pharmacognosy, Faculty of Pharmacy, Mahidol University, Bangkok, Thailand.
Abstract

Complete 1H-nmr data and unambiguous assignments of the 13C-nmr spectra of phyllanthin [1] and hypophyllanthin [2] were obtained through extensive nmr studies, including homonuclear COSY, homonuclear decoupling, APT, HETCOR, nOe difference, selective INEPT, and COLOC experiments. The absolute configuration of hypophyllanthin [2] was determined by cd. Neither of these Lignans demonstrated significant cytotoxic activity when evaluated with a battery of cultured mammalian cells, but both were found to enhance the cytotoxic response mediated by vinblastine with multidrug-resistant KB cells. In addition, 1 was found to displace the binding of vinblastine with membrane vesicles derived from this cell line, suggesting an interaction with the P-glycoprotein.

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