Cytotoxic pheophorbide-related compounds from Clerodendrum calamitosum and C. cyrtophyllum

H. H. Cheng, H. K. Wang, J. Ito, K. F. Bastow, Y. Tachibana, Y. Nakanishi, Z. Xu, T. Y. Luo, K. H. Lee

Research output: Contribution to journalArticlepeer-review

80 Citations (Scopus)


Three pheophorbide-related compounds (1-3) were isolated from the leaves and stems of Clerodendrum calamitosum. The methyl ester of 3 (6) and the known (10S)-hydroxypheophytin a (7) also were isolated from leaves of the related plant Clerodendrum cyrtophyllum. Compounds 1 and 6 were isolated for the first time as naturally occurring products from a plant source. All structures were elucidated by detailed spectroscopic analysis. Biological evaluation showed that 1 and 2 exhibited strong cytotoxicity against human lung carcinoma (A549), ileocecal carcinoma (HCT-8), kidney carcinoma (CAKI-1), breast adenocarcinoma (MCF-7), malignant melanoma (SK-MEL-2), ovarian carcinoma (1A9), and epidermoid carcinoma of the nasopharynx (KB), and its etoposide- (KB-7d), vincristine- (KB-VCR), and camptothecin-resistant (KB-CPT) subclones. Compound 3 was less cytotoxic than 1 and 2. Compounds 4-6, the methyl esters of 1-3, showed strongly increased cytotoxicity compared with the parent acids. Interestingly, 6 was the most active derivative among these compounds. Compound 7 was inactive.

Original languageEnglish
Pages (from-to)915-919
Number of pages5
JournalJournal of Natural Products
Issue number7
Publication statusPublished - 2001
Externally publishedYes

ASJC Scopus subject areas

  • Plant Science
  • Chemistry (miscellaneous)
  • Drug Discovery
  • Organic Chemistry
  • Pharmacology


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