chlorophyll-a and Kidney-Neoplasms

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.

Topics: Adenocarcinoma; Antineoplastic Agents, Phytogenic; Breast Neoplasms; Camptothecin; Cell Survival; Chlorophyll; Dose-Response Relationship, Drug; Drug Resistance; Etoposide; Female; Humans; Ileal Neoplasms; KB Cells; Kidney Neoplasms; Lung Neoplasms; Magnetic Resonance Spectroscopy; Melanoma; Molecular Structure; Ovarian Neoplasms; Plant Leaves; Plant Stems; Plants, Medicinal; Stereoisomerism; Structure-Activity Relationship; Taiwan; Tumor Cells, Cultured; Vincristine