Ent-abietane diterpenoids from Suregada zanzibariensis Baill. (Euphorbiaceae), their cytotoxic and anticancer properties

• Published in: Natural product research 2019-11, Vol.33 (22), p.3240-3247
• Main Authors: Mangisa, Mandisa, Tembu, Vuyelwa J., Fouche, Gerda, Nthambeleni, Rudzani, Peter, Xolani, Langat, Moses K.
• Format: Article
• Language: English
• Subjects: Abietanes - chemistry; Abietanes - isolation & purification; Abietanes - pharmacology; Anticancer properties; Bark; Bioassays; Biotechnology; Breast; Breast cancer; Cancer; cancer cell lines; Cell Line, Tumor; Cell Proliferation - drug effects; Circular dichroism; Cytotoxicity; Dichloromethane; Dichroism; Diterpenes; Diterpenes - isolation & purification; Diterpenes - pharmacology; Drug Screening Assays, Antitumor; ent-abietane diterpenoid lactone; Euphorbiaceae; Euphorbiaceae - chemistry; Fractionation; Humans; Kidneys; Melanoma; Molecular Structure; Plant extracts; Plant Extracts - chemistry; Plant Extracts - pharmacology; Renal cell carcinoma; Spectrum Analysis; Stereoisomerism; Suregada - chemistry; Suregada zanzibariensis; Tumor cell lines
• ISSN: 1478-6419; 1478-6427
• DOI: 10.1080/14786419.2018.1470628

The stem bark extract of Suregada zanzibariensis afforded a previously undescribed ent-abietane diterpenoid trivially named mangiolide (1) and a known jolkinolide B (2) via anticancer bioassay-guided fractionation. The CH 2 Cl 2 :MeOH extract of S. zanzibariensis was initially analysed for its anticancer properties against three cancer cell lines, renal (TK10), melanoma (UACC62), and breast (MCF7) and was found to be potent at low μg/mL ranges. Compound 1, 6α-acetoxy-14-keto-ent-abieta-7(8),13(15)-diene-16,12-olide (mangiolide) inhibited the growth of renal (TK10) with a GI 50 of 0.02 μg/mL; a GI 50 of 0.03 μg/mL for melanoma (UACC62) and a GI 50 of 0.05 μg/mL for breast (MCF7) cancer cell lines. Compound 2, 8,13-diepoxy-13,15-ent-abietene-16,12-olide (jolkinolide B) inhibited the growth (GI 50 ) of the cell lines at 3.31 μg/mL for renal (TK10), 0.94 μg/mL for melanoma (UACC62) and 2.99 μg/mL for the breast (MCF7). The structures were established on the basis of their spectroscopic analysis and the absolute stereostructures assigned using electronic circular dichroism (ECD).