title: Bioassay-guided investigation of the Tanzanian plant Pyrenacantha kaurabassana for potential anti-HIV-active compounds.
abstract: Two new anti-HIV xanthones, 6,7,11-trihydroxy-10-methoxy-9-(7-methoxy-3-methyl-1-oxoisochroman-5-yl)-2-methyl-12-oxo-12H-benzo[b]xanthene-4-carboxylic acid (1) and 6,7-dihydroxy-10,11-dimethoxy-9-(7-methoxy-3-methyl-1-oxoisochroman-5-yl)-2-methyl-12-oxo-12H-benzo[b]xanthene-4-carboxylic acid (2), and a new hexadecahydrochrysen-3-ol (3) were isolated from the tubers of Pyrenacantha kaurabassana. Compounds 1 and 2 showed moderate anti-HIV activity when tested in the deCIPhR assay on HIV virus type NL4-3, with IC₅₀ values of 21 and 2 μg/mL, respectively.
authors.affiliation: Molecular Sciences Institute, School of Chemistry,  University of the Witwatersrand , P.O. Wits 2050, Johannesburg, South Africa.
authors.forename: Justin J
authors.initials: JJ
authors.lastname: Omolo
authors.forename: Vinesh
authors.initials: V
authors.lastname: Maharaj
authors.forename: Dashnie
authors.initials: D
authors.lastname: Naidoo
authors.forename: Thomas
authors.initials: T
authors.lastname: Klimkait
authors.forename: Hamisi M
authors.initials: HM
authors.lastname: Malebo
authors.forename: Samwel
authors.initials: S
authors.lastname: Mtullu
authors.forename: Herbert V M
authors.initials: HV
authors.lastname: Lyaruu
authors.forename: Charles B
authors.initials: CB
authors.lastname: de Koning
mesh_terms: D019380:Anti-HIV Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D028082:Boraginaceae / Q000737:chemistry*; D006678:HIV; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D013237:Stereoisomerism; D013636:Tanzania; D044004:Xanthones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*
chemical_list: C577669:6,7,11-trihydroxy-10-methoxy-9-(7-methoxy-3-methyl-1-oxoisochroman-5-yl)-2-methyl-12-oxo-12H-benzo(b)xanthene-4-carboxylic acid; C577670:6,7-dihydroxy-10,11-dimethoxy-9-(7-methoxy-3-methyl-1-oxoisochroman-5-yl)-2-methyl-12-oxo-12H-benzo(b)xanthene-4-carboxylic acid; D019380:Anti-HIV Agents; D044004:Xanthones