lichexanthone and Leukemia-P388

A bioassay-guided investigation of Gustavia hexapetala led to the isolation of a new cancer cell growth inhibitor designated gustastatin (1) and four previously known cancer cell growth inhibitors that included betulinic acid (2). The structures were assigned on the basis of analyses of HRMS combined with 1D and 2D NMR data. The structure of portentol (5) was confirmed by an X-ray crystal structure determination.

Topics: Animals; Antineoplastic Agents, Phytogenic; Betulinic Acid; Brazil; Crystallography, X-Ray; Drug Screening Assays, Antitumor; Lecythidaceae; Leukemia P388; Mice; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Oleanolic Acid; Pentacyclic Triterpenes; Phenols; Plants, Medicinal; Trees; Triterpenes

Bioassay (P388 lymphocytic leukemia cell line and human cancer cell lines)-guided separation of an extract prepared from the stem bark and twigs of the previously uninvestigated Ruprechtia tangarana led to the isolation of a new isocarbostyril designated ruprechstyril (1), secalonic acid A (2), 2'-O-methylevernic acid (3), 3,3',4-tri-O-methylflavellagic acid (4), lichexanthone (5), methyl asterrate (6), and 3beta,22E,24S-stigmasta-5,22-dien-3-ol (7). Only secalonic acid A exhibited cancer cell and microbial growth inhibition. The structure of ruprechstyril (1) was determined by HRMS and 1D and 2D NMR spectra and confirmed by single-crystal X-ray analysis. The structures and absolute stereochemistry of five of the other compounds were also established by X-ray crystal structure determination.

Topics: Animals; Antineoplastic Agents, Phytogenic; Crystallography, X-Ray; Drug Screening Assays, Antitumor; Humans; Hydroxyquinolines; Leukemia P388; Molecular Conformation; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Peru; Plants, Medicinal; Polygonaceae; Stereoisomerism