Cytotoxic polyoxygenated cyclohexene derivatives from the aerial parts of Uvaria cherrevensis.

Three previously undescribed polyoxygenated cyclohexene derivatives named cherrevenol M (1), cherrevenol N (2), and cherrevenone (3), together with nine related known analogues 4-12 were isolated from the ethyl acetate fraction partitioned from the methanol extract of the aerial parts of Uvaria cherrevensis (Annonaceae). The determination of the structures and their relative configurations of the isolated compounds were established by spectroscopic techniques, electronic circular dichroism (ECD) analysis as well as comparison with the literature data. For cherrevenone (3), the relative and absolute configurations were also confirmed by using X-ray diffraction and ECD techniques, respectively. Compounds isolated except for compounds 8 and 10 were evaluated for their cytotoxic activity and cherrevenone (3) showed moderate cytotoxic activity against all cancerous cell lines except for ASK cell line with ED50 values ranging from 1.04 ±â€¯0.13 to 10.09 ±â€¯4.31 µM.

A New Neolignan, and the Cytotoxic and Anti-HIV-1 Activities of Constituents from the Roots of Dasymaschalon sootepense.

Bioassay-guided isolation from the ethyl acetate extract of Dasymaschalon sootepense roots led to the isolation of twelve compounds including a new dihydrobenzo-furan neolignan, (+)-(2S,3S)-2,3-dihydro-2-(3,4-dimethoxyphenyl)-3-methylbenzofuran-5-carbaldehyde (5), and eleven known compounds (1-4, and 6-12). The chemical structures and stereochemistry of all the isolated compounds were established by spectroscopic techniques. The known compounds 4 and 6 have been fully characterized spectroscopically, including their absolute configurations. Cytotoxic and anti-HIV-1 reverse transcriptase (RT) activities of compounds 1-3, 5 and 8-12 were determined. Among compounds screened, compounds 2, 3 and 10 displayed weak cytotoxic activity with ED50 values ranging from 9.6-47.5 µM and only compound 2 was found weakly active against HIV-1 RT with an IC50 value of 323.2 µM.

Polyoxygenated cyclohexene derivatives isolated from Dasymaschalon sootepense and their biological activities.

Six new naturally occurring polyoxygenated cyclohexene derivatives together with eight related known derivatives, two known alkaloids, and two known flavonoid derivatives were isolated from bioassay-guided fractionation of the ethyl acetate extract of the leaves and twigs of Dasymaschalon sootepense. The structure elucidation and determination of absolute configurations were established by various spectroscopic methods, X-ray diffraction techniques as well as comparison with the literature data. Several isolated compounds were evaluated for their cytotoxic, anti-HIV-1 RT and anti-inflammatory activities.

Cytotoxic alkaloids from leaves and twigs of Dasymaschalon sootepense.

Bioassay-guided fractionation of the cytotoxic ethyl acetate fraction of the sequential methanol extract from the leaves and twigs of Dasymaschalon sootepense led to the isolation of a new 7-hydroxy aporphine alkaloid, 6a,7-dehydrodasymachaline (1) along with the five known compounds (-)-nordicentrine (2), dicentrinone (3), (-)-sinactine (4), aristolactam AII (5) and epiberberine (6). Their structures were elucidated by spectroscopic methods. This is the first report of alkaloids 1-2 and 5-6 from the genus Dasymaschalon. Compounds 1 and 5 showed cytotoxicity against a panel of cancer cell lines.

Anti-HIV-1 and anti-inflammatory lupanes from the leaves, twigs, and resin of Garcinia hanburyi.

Two new lupanes, 2 alpha-acetoxy-3 beta-hydroxy-19 beta-hydrogen-lup-20(29)-en-28-oic acid (2-acetoxyalphitolic acid) ( 1) and 2 alpha-hydroxy-3 beta-acetoxy-19 beta-hydrogen-lup-20(29)-en-28-oic acid (3-acetoxyalphitolic acid) ( 2), together with the known betulinic acid ( 3), betulin ( 4), and stimasterol-3- O- beta- D-glucopyranoside ( 5), were isolated from the leaves and twigs of GARCINIA HANBURYI. Compounds 1- 3 were also isolated from the resin of this plant. The structure of 2 was confirmed by single-crystal X-ray diffraction analysis. All of the lupanes ( 1- 4) displayed anti-HIV-1 activities in the anti-HIV-1 reverse transcriptase (IC (50) values 16.3-116.9 microg/mL) and syncytium assays (EC (50) 5.6-73.6 microg/mL, SI 1.7-3.3). Moreover compounds 1- 4 exhibited anti-inflammatory activity in an ethyl phenylpropiolate (EPP)-induced ear edema model.

Cytotoxic and anti-HIV-1 caged xanthones from the resin and fruits of Garcinia hanburyi.

Three new caged xanthones, 7-methoxydesoxymorellin (1), 2-isoprenylforbesione (2) and 8,8a-epoxymorellic acid (3), together with nine known caged xanthones were isolated from the EtOAc extracts of resin and fruits of Garcinia hanburyi. The structures were determined by spectroscopic methods. Most of the isolated compounds showed significant cytotoxicities against a panel of mammalian cancer cell lines. Compound 3, together with the known compounds desoxymorellin, morellic acid, gambogic acid, hanburin, forbesione and dihydroisomorellin, exhibited anti-HIV-1 activity in the reverse transcriptase (RT) assay while the known compounds desoxygambogenin and dihydroisomorellin were found moderately active in the syncytium assay. This work represents the first report on the anti-HIV-1 activities of caged xanthones.

Anti-HIV-1 constituents from leaves and twigs of Cratoxylum arborescens.

Two new xanthones, 1,3,8-trihydroxy-2,4-dimethoxyxanthone (1) and 1,7-dihydroxy-2,8-dimethoxyxanthone (2), along with twelve known compounds 3 - 14 were isolated from leaves and twigs of Cratoxylum arborescens. Compound 1, euxanthone (4), betulinic acid (8), lup-20(29)-ene-3beta,30-diol (9), 3beta-hydroxylup-20(29)-en-30-oic acid (10) and 3,4-dihydroxybenzoic acid (11) displayed anti-HIV-1 activities in the syncytium assay using (Delta)(Tat/Rev)MC99 virus and the 1A2 cell line system (EC (50) values between 3.9 and 32.2 microg/mL with TI ranging from 1.5 to 11.7), while 1,3,7-trihydroxy-6-methoxy-4,5-diisoprenylxanthone (3), 4, and 8 - 10 inhibited HIV-1 reverse transcriptase with IC (50) values between 8.7 and 84.9 microg/mL.

Cytotoxic coumarins from Mammea harmandii.

Two new naturally occurring coumarins, isomesuol (1) and mammearin A (2), together with nine known Mammea coumarins 3-11 were isolated from the EtOAc extract of the leaves and twigs of Mammea harmandii. Coumarins 1, 3 and 4 showed cytotoxicity against a panel of mammalian cancer cell lines. Their structures were determined by spectroscopic methods. The assignments of 13C-NMR signals of isomesuol (1), which was isolated for the first time as a natural product, have been revised.