Three new triterpenes, 3,4-seco-3,11β-epoxyfriedel-4(23)-en-3β-ol (1), friedelan-3α,11β diol (2), 7β,26-epoxyfriedelan-3a,7a-diol (3), a mixture of two new triterpenes 3α-hydroxyfriedelan-29-yl palmitate (4) and 3α-hydroxyfriedelan-29-yl stearate (5) and eleven known compounds were obtained from the hexane extract of Maytenus quadrangulata leaves. The structures and the relative stereochemistry of the new triterpenes were established through 1D/2D nuclear magnetic resonance (NMR), high resolution mass spectrometry (HRMS), and Fourier transform infrared (FTIR) spectral data. The hexane extract and isolated compounds were submitted to the cytotoxicity assays against leukemia (THP-1 and K562), ovarian (TOV-21G) and breast cancer (MDA-MB-231) cell lines. Compounds 1, 2 and 11β-hydroxyfriedelan-3-one (15) displayed high cytotoxicity and selectivity against leukemic cells when compared to positive control cytarabine (for THP-1) and imatinib (for K562). Furthermore, compound 2 showed similar cytotoxicity and an enhanced selectivity towards ovarian and breast cells in comparison to positive control etoposide.

Maytenus distichophylla is a medicinal species used in Northeast of Brazil. The hexane (HE), chloroform (CE), ethyl acetate (EAE) and methanol (ME) extracts and compounds from its roots were evaluated for their protective activity against Staphylococcus aureus and Candida albicans. The cytotoxicity for chronic myeloid leukemia (K562), acute monocytic leukemia (THP-1), and peripheral blood mononuclear cells of normal individuals (PBMC) cells was established by MTT method using etoposide as standard. The in vivo toxicity of samples was determined using Caenorhabditis elegans model. From HE and CE were isolated: friedelan-3-one (1), b-sitosterol (2), 3-oxo-olean-9(11),12-diene (3), a mixture of pristimerin (4) and 11a-hydroxylup-20(29)-en-3-one (5), 30-hydroxylup-20(29)-en-3-one (6), friedelane-3,7-dione (7), tingenone (8) and triacylglycerol (9). The structures of 1-9 were confirmed by spectral data. All samples reduced the viability of S. aureus and present no effect against C. albicans. The HE, CE, mixture of 4/5 and 8 reduced 75% of S. aureus viability. Cytotoxic effect for K562 and THP-1 cells was caused by compounds 1, 2 and 8. All samples displayed selectivity for leukemic cells and low toxicity to PBMC cells, suggesting their potential as anticancer agents. Extracts and compounds were non-toxic to L1 larvae of C. elegans. However, most of them reduced significantly young adult worm’s survival, being considered as potential nematicides.

Two new compounds, caryopristimerin and 2α,3α,22β-trihydroxy-21-oxo-29-nor-friedelan-24-oic acid, were isolated from the hexane/ethyl ether extract of Salacia crassifolia roots. Caryopristimerin represents the first example of a homo Diels-Alder adduct of a sesquiterpene and a triterpene, and the new 29-nor-friedelane displays a highly oxygenated A ring with a carboxylic group at the unusual C-5 position. The new compounds were elucidated by infrared (IR), high-resolution-atmospheric pressure chemical ionization-mass spectrometry (HR-APCI-MS), 1D/2D nuclear magnetic resonance (NMR) and single crystal X-ray diffraction analysis. Additionally, the known compounds 3-oxo-29-hydroxyfriedelane, pristimerin, tingenone and netzahualcoyonol are herein reported for the first time as constituents of S. crassifolia. Their structures were established by spectroscopic analysis.