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.

Salacia crassifolia traditionally known as “Bacupari-do-Cerrado” is used to treat kidney problems, and as a healing agent for coughs and malaria. The phytochemical study of the S. crassifolia roots led to the isolation of thirteen compounds: abruslactone-A (1), urs-12-ene-3β,25,30-triol (2), carioprystimerin (3), β-sitosterol (4), pristimerin (5), dispermoquinone (6), netzahualcoyonol (7), 20-hydroxy-20-epi-tingenone (8), 6-oxo-pristimerol (9), 9β,10β-epoxi-3β-hydroxy-1βH,4βH,5βH,7βH,11αH-guaian-12,8β-olide (10), 3-O-b-D-glucosyl-b-sitosterol (11), 4`-O-methylepigalocatechin (12) and cerebroside (13). The chemical structures of 1-13 were determined by IR, 1D/2D NMR together with X-ray diffractometry. Compounds 2 and 10 are herein described for the first time. Extracts of S. crassifolia and compounds 3, 5, 8 and 9 were evaluated on acetylcholinesterase inhibition, in vitro cytotoxic activity and in vivo toxicity tests using Caenorhabditis elegans model. All tested compounds inhibited acetylcholinesterase, and compounds 3, 8 and 9 demonstrated a greater potential when compared to the standard eserine. The tested compounds showed low cytotoxicity against the THP-1, K562 and MDA-MB-231 cancer cell lines. None of the tested compounds and extracts were toxic against C. elegans since the larvae survival rate in L1 stage was higher than 90%.

The composition of essential oils from flowers of Solanum stipulaceum Roem & Schult collected in May and September was studied for the first time. Effects of g-radiation on volatile constituents were investigated by gas chromatography (GC) with flame ionization detector (FID). In addition, the antileukemic activity was studied by a 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) colorimetric assay against human cell lines HL-60 and THP-1. The main constituents of the essential oil of flowers collected in May were β-caryophyllene (25.8%), γ-gurjunene (11.9%), and β-gurjunene (8.2%), whereas the essential oil of flowers collected in September was mainly composed of β-caryophyllene (26.5%), caryophyllene oxide (11.0%), and γ-gurjunene (10.0%). The main components of essential oil from flowers collected in September were not significantly affected by γ-radiation at lower doses than 10.0 kGy. No cytotoxic activity in leukemic cell lines was observed for non-irradiated samples. However, irradiated samples exhibited slightly cytotoxic activity.