title: Isolation and anti-HIV-1 activity of a new sesquiterpene lactone from Calocephalus brownii F. Muell.
abstract: As part of our ongoing collaborative effort to discover potential anti-HIV-1 agents from plants, the CH2Cl2 extract of Calocephalus brownii F. Muell. was phytochemically investigated, which resulted in the isolation of two sesquiterpene lactones of the cis-fused guaianolides type, one new identified as 1α-hydroxy-3βH-3α,4α-epoxy-4,10-dimethyl-5αH,7αH,8βH,10αH-guai-11(13)-ene-7,8-olide (1) and one known identified 1αH-4α-hydroxy-4,10-dimethyl-5αH,7αH,8βH,10αH-guai-11(13)-ene-7,8-olide (2). Their structures were elucidated on the bases of IR, UV, 1D-NMR, 2D-NMR, DIFNOE and high-resolution ESI-TOF-MS. The anti-HIV-1 activity was evaluated and revealed that STLs (1 and 2) caused a reduction for the viability of mock-infected MT-4 cells by CC50 = 29.1 and 0.5 μg/mL, respectively, and caused 50% protection of MT-4 cells against HIV-1 induced cytopathogeneticy by EC50 = 29.1 and 0.5 μg/mL, respectively, as compared with Efavirenz (EFV) as positive control that showed a CC50 = 11.6 and EC50 = 0.0006 μg/mL, using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide method.
authors.affiliation: a Danish Institute of Agricultural Sciences (DIAS), Department of Food Science, Research Center Aarslev , Aarhus University , Kirstinebjergvej 10, DK-5792, Aarslev , Denmark.
authors.forename: Magdy M D
authors.initials: MM
authors.lastname: Mohammed
authors.forename: Lars P
authors.initials: LP
authors.lastname: Christensen
authors.forename: Paolo L
authors.initials: PL
authors.lastname: Colla
mesh_terms: D019380:Anti-HIV Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D019659:Asteraceae / Q000737:chemistry*; D015497:HIV-1 / Q000187:drug effects*; D007783:Lactones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D045789:Sesquiterpenes, Guaiane / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*
chemical_list: C000591260:1alpha-hydroxy-3betaH-3alpha,4alpha-epoxy-4,10-dimethyl-5alphaH,7alphaH,8betaH,10alphaH-guai-1(13)-ene-7,8-olide; D019380:Anti-HIV Agents; D007783:Lactones; D045789:Sesquiterpenes, Guaiane