Imines and lactones derived from friedelanes and their cytotoxic activity

• Published in: Natural product research Vol. 34; no. 6; pp. 810 - 815
• Main Authors: Aguilar, Mariana G., Sousa, Grasiely F., Evangelista, Fernanda C. G., Sabino, Adriano P., Vieira Filho, Sidney A., Duarte, Lucienir P.
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 18.03.2020; Taylor & Francis Ltd
• Subjects: Antineoplastic Agents - chemical synthesis; Antineoplastic Agents - isolation & purification; Antineoplastic Agents - pharmacology; Biotechnology; Breast cancer; Carbonyl compounds; Carbonyl groups; Carbonyls; Celastraceae - chemistry; Cell Line, Tumor; Cytotoxicity; cytotoxicity property; Cytotoxins - chemical synthesis; Cytotoxins - isolation & purification; Cytotoxins - pharmacology; friedelane derivatives; Humans; Imines; Imines - chemical synthesis; Imines - chemistry; K562 cell line; Lactones; Lactones - chemical synthesis; Lactones - chemistry; Leukemia; NMR; Nuclear magnetic resonance; Ovarian cancer; Oxidation; Oximes; Pentacyclic triterpenes; Plant Leaves - chemistry; Structure-Activity Relationship; THP-1 cell line; TOV-21G cell line and MDA-MB-231 cell line; Triterpenes - chemistry; Triterpenes - isolation & purification; Tumor cell lines; TOV-21G cell line and MDA-MB-231 cell line; cytotoxicity property; K562 cell line; friedelane derivatives; Pentacyclic triterpenes; THP-1 cell line
• ISSN: 1478-6419; 1478-6427
• DOI: 10.1080/14786419.2018.1508137

Friedelan-3-one (1) and friedelane-3,16-dione (2) isolated from leaves and branches of Maytenus robusta Reissek were subjected to structural modifications via nucleophilic addition to the carbonyl group and Baeyer-Villiger oxidation in order to synthesize potential cytotoxic compounds. The oximes friedelane-3-hydroxyimino (3) and 3-hydroxyiminofriedelan-16-one (4) together with the lactones friedelane-3,4-lactone (5) and 3,4-lactonefriedelan-16-one (6) were characterized by IR and NMR spectroscopic analyses. Compounds 4 and 6 are reported for the first time. Cytotoxic screening via MTT assay in human leukemia cell lines (THP-1 and K562) demonstrated no significant improvement of compounds 3-6 when compared to the starting materials. Only compounds 3 and 5 demonstrated an improvement against K562 cells. However, the same assay on ovarian and breast cancer cell lines (TOV-21G and MDA-MB-231) showed a reduction in the IC 50 for compounds 4-6, indicating that ring A modifications may enhance the biological potential.