Lupane Triterpenes with Antileukemia Activity from Maytenus quadrangulata

Maytenus quadrangulata occurs naturally in the Brazilian biomes Caatinga and Atlantic Forest, and previous studies have demonstrated its potential as a source of bioactive molecules. In light of this, a phytochemical study of the chloroform extract of Maytenus quadrangulata branches was carried out, yielding the new triterpene 30-oxo-2,3-seco-lup-20(29)-ene-2,3-dioic acid (1) and a mixture containing the new semisynthetic triterpene 25-hydroxy-7-oxofriedelan-3α-yl acetate (2). In addition, seven known compounds were also obtained: friedelan-3-one (3), friedelan-3β-ol (4), friedelan-3α-ol (5), a mixture of long-chain fatty acids of β-sitosterol and lupeol-β-sitosterol alkanoate (6) and lupeol alkanoate (7), friedelane-3,7-dione (8) and 2,3-seco-lup-20(29)-ene-2,3-dioic acid (9). Structural elucidation of the isolated metabolites was performed using 1H and 13C nuclear magnetic resonance (NMR). The chemical structures of the new compounds, 1 and 2, were confirmed by the analysis of two-dimensional NMR spectra (HSQC, HMBC, COSY, and NOESY). An in vitro cytotoxicity assay against the THP-1 and K-562 leukemia cell lines and an in silico analysis using ADMETLab 3.0 were performed for compounds 1 and 9. The novel triterpene (1) exhibited the highest cytotoxicity and the most favorable drug-like profile, underscoring its potential as an anticancer therapeutic.