Purification and characterization of anti-HIV-1 protein from Canna indica L. leaves.

A novel 10 kDa protein with anti-HIV-1 reverse transcriptase (RT) inhibitory activity was isolated from leaves of Canna indica L. using a combination of native-PAGE and ammonium sulfate precipitation. HIV-1 and RT inhibitory activity was measured using a syncytium forming (deltaTat/Rev) MC99 virus in Tat/Rev transfected 1A2 cell line and ELISA technique, respectively. Edman N-terminal and internal amino acid sequence (using LC-MS-MS) determination revealed the 10 kDa Canna indica L. leaf protein as a putative plastocyanin. This is the first report of a plant plastocyanin with HIV-1 RT inhibitory property.

A new conjugated amide-dimer from the aerial parts of Piper submultinerve.

Bioassay-guided fractionation and purification of the aerial parts of Piper submultinerve led to the isolation of a new conjugated amide-dimer, submultinamide A (1), along with 11 known compounds. The structures were determined on the basis of spectroscopic methods. Among the tested compounds, pellitorine (2), guineensine (4), N-benzylcinnamide (6) and aristolactam BII (8) showed significant activities in the anti-syncytium assay using (ΔTat/Rev)MC99 virus and 1A2 cell line system, whereas 2 was most active (EC50 35.1 µM and selectivity index 4.7). In the HIV-1 reverse transcriptase assay, only 4 was active with IC50 50.8 µM.

DNA topoisomerase IIα inhibitory and anti-HIV-1 flavones from leaves and twigs of Gardenia carinata.

Four new flavones, 5,2'-dihydroxy-7,3',4',5'-tetramethoxyflavone (1), 5,2',5'-trihydroxy-7,3',4'-trimethoxyflavone (2), 5,7,2',5'-tetrahydroxy-6,3',4'-trimethoxyflavone (3) and 5,2',5'-trihydroxy-6,7,3',4'-tetramethoxyflavone (4), along with the known 5,3'-dihydroxy-6,7,4',5'-tetramethoxyflavone (5), 5,7,3',5'-tetrahydroxy-6,4'-dimethoxyflavone (6), syringaldehyde, vanillic acid and scopoletin were isolated from the leaves and twigs of Gardenia carinata (Rubiaceae). Their structures were determined by spectroscopic methods. Flavone 2 exhibited cytotoxic activity against P-388 and MCF-7 cell lines, while 3, 5 and 6 were active only in P-388 cell line. All active compounds were found to inhibit DNA topoisomerase IIα activity, which may be responsible for the observed cytotoxicity. Flavones 1-3, 5 and 6 also exhibited anti-HIV-1 activity in the anti-syncytium assay using (∆Tat/rev)MC99 virus and 1A2 cell line system; 2 was most potent. Only flavones 1 and 6 showed considerably activity against HIV-1 reverse transcriptase.

A new diarylheptanoid from the rhizomes of Zingiber mekongense.

A new diarylheptanoid, (3S,5S)-3,5-diacetoxy-1,7-bis(3,4,5-trimethoxyphenyl)heptane (1), together with the known docosyl trans-ferulate (2), (1S,2S,4S)-p-menthan-1,2,4-triol (3), 5αH-eudesmane-4α,11-diol (4), 5αH-eudesmane-4ß,11-diol (5), 4α,10ß-dihydroxy-1ßH,5αH-guaia-6-ene (guaianediol) (6), (+)-galanolactone (7), (E)-labda-8(17),12(13)-dien-15,16-olide (8), labda-8(17),13(14)-dien-15,16-olide (9), 3,5-dihydroxy-7,4'-dimethoxyflavone (10) and 3,5,3'-trihydroxy-7,4'-dimethoxyflavone (11) were isolated from the rhizomes of Zingiber mekongense. Their structures were determined by spectroscopic methods. The stereochemistry of 1 was proved through chemical conversion. Compounds 1, 4-7 and 9-11 exhibited anti-HIV-1 activities in the anti-syncytium assay using (∆Tat/rev)MC99 virus and 1A2 cell line system, while only compounds 7 and 11 were found active in the HIV-1 reverse transcriptase assay.

Determination of a pyranocoumarin and three carbazole compounds in Clausena excavata by RP-HPLC.

Clausenidin, O-methylmukonal, 3-formyl-2,7-dimethoxycarbazole, and clauszoline-J, isolated from the rhizomes and roots of Clausena excavata, exhibit anti-HIV-1 activity in a syncytial assay with EC(50) values of 5.3, 12.0, 29.1, and 34.2 microM, respectively. Due to the highly active anti-HIV-1 property, quantitative analysis of four compounds are investigated. The direct analysis of these four compounds in the crude extracts of the combined rhizomes and roots of Clausena excavata from ten various sources in Thailand by high-performance liquid chromatography is accomplished. Chromatographic separation is achieved on a C(18) column, and the mobile phase is a mixture of methanol and distilled water in a mode of isocratic or gradient elution detected at 254 nm at a flow rate of 0.6 mL/min for clausenidin, at 274 nm at a flow rate of 0.6 mL/min for O-methylmukonal, at 298 nm at a flow rate of 0.4 mL/min for 3-formyl-2,7-dimethoxycarbazole, and at 242 nm at a flow rate of 0.4 mL/min for clauszoline-J. This is the first quantitative analysis of these four anti-HIV-1 compounds from the crude extract without prior isolation and purification steps.

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.

Anti-HIV-1 diterpenoids from leaves and twigs of Polyalthia sclerophylla.

Bioassay-guided fractionation and purification of the anti-HIV-1-active MeOH extract from the leaves and twigs of Polyalthia sclerophylla led to the isolation of two new compounds, ENT-kaur-sclerodimer ( 1) and cyclotucanol 3-palmitate ( 2), along with the known ENT-kaur-16-en-19-oic acid ( 3), 15 beta-hydroxy- ENT-kaur-16-en-19-oic acid ( 4), 15 beta-acetoxy- ENT-kaur-16-en-19-oic acid ( 5), 15-oxo- ENT-kaur-16-en-19-oic acid ( 6), 16 alpha,17-dihydroxy- ENT-kauran-19-oic acid ( 7), 16 alpha-hydroxy- ENT-kauran-19-oic acid (xylopic acid) ( 8), a pseudodimer (15 alpha-hydroxy- ENT-kaur-16-en-19-oic acid/17-hydroxy- ENT-kaur-15-en-19-oic acid) ( 9), ermanin, nicotiflorin, and allantoin. Among these isolates, compound 3 was the most active in both anti-syncytium (EC (50) 13.7 microg/mL and selectivity index 3.1) and HIV-1 reverse transcriptase (IC (50) 34.1 microg/mL) assays.

Dichapetalin-type triterpenoids and lignans from the aerial parts of Phyllanthus acutissima.

Chemical investigation of the aerial parts of Phyllanthus acutissima resulted in the isolation of five new dichapetalin-type triterpenoids, acutissimatriterpenes A-E ( 1- 5), and two new lignans, acutissimalignans A ( 6) and B ( 7), along with two known lignans and three known ellagic acid derivatives. The structures of 1- 7 were determined mainly on the basis of spectroscopic methods. The compounds obtained were evaluated for cytotoxic and anti-HIV-1 activities.

The anti-inflammatory effects and the inhibition of neutrophil responsiveness by Barleria lupulina and Clinacanthus nutans extracts.

AIM OF THE STUDY: To investigate the anti-inflammatory activities of Barleria lupulina Lindl and Clinacanthus nutans (Burm.f.) Lindau extracts using two neutrophil-dependent acute inflammatory models and, in order to elucidate underlying cellular mechanisms, the effects of the extracts on human neutrophil responsiveness was investigated. MATERIALS AND METHODS: The in vivo inflammatory models examined were carrageenan-induced paw oedema and ethyl phenylpropiolate-induced ear oedema in rats. Myeloperoxidase (MPO) activity was assayed as an indicator of neutrophil migration. Human neutrophil functional responsiveness was determined by measuring fMLP-induced chemotaxis, superoxide anion generation (SAG), and release of MPO and elastase. Apoptosis was assessed morphologically and flow-cytometrically. Neutrophil viability was assessed by trypan blue exclusion and MTT cytotoxicity assays. RESULTS: Both extracts induced powerful dose-dependent inhibitory effects in both edema models in rats. Importantly, there was a significant inhibition of MPO activity in the inflamed tissue indicating that the anti-inflammatory effect of the extracts is associated with reduced neutrophil migration. Although both extracts did not affect neutrophil viability or apoptosis, treatment of neutrophils with the extracts concentration-dependently inhibited fMLP-induced chemotaxis, SAG, and MPO and elastase release. CONCLUSIONS: These findings suggest that the powerful anti-inflammatory properties of Barleria lupulina Lindl and Clinacanthus nutans (Burm.f.) Lindau extracts are mediated, in part, by inhibition of neutrophil responsiveness.Barleria lupulina Lindl, Clinacanthus nutans (Burm. f.)Lindau; Oedema formation; Neutrophil responsiveness.

Anti HIV-1 flavonoid glycosides from Ochna integerrima.

Bioassay-guided fractionation of the anti-HIV-1 active EtOAc extract from leaves and twigs of Ochna integerrima led to the isolation of five new flavonoid glycosides 1 - 5, five known flavonoids 6 - 10, and two known flavonoid glycosides 11 and 12. Structures were determined based on spectroscopic analyses. 6- gamma, gamma-Dimethylallyldihydrokaempferol 7- O- beta-D-glucoside (1), 6-gamma, gamma-dimethylallylquercetin 7- O- beta- D-glucoside (3), 6-(3-hydroxy-3-methylbutyl)taxifolin 7- O- beta-D-glucoside (4), 6-(3-hydroxy-3-methylbutyl)quercetin 7- O-beta-D-glucoside (5), and 6-gamma, gamma-dimethylallyltaxifolin 7-O-beta-D-glucoside (11) showed anti-HIV-1 activities in the syncytium assay using the (Delta Tat/rev)MC99 virus and the 1A2 cell line system with EC(50) values ranging from 14.0 - 102.4 microg/mL. Furthermore, ochnaflavone 7''-O-methyl ether (7) and 2'', 3''-dihydroochnaflavone 7''-O-methyl ether (8) were very active; they exerted activities in the syncytium assay with EC(50) values of 2.0 and 0.9 microg/mL, respectively, and likewise inhibited HIV-1 reverse transcriptase (RT) with IC(50) values of 2.0 and 2.4 microg/mL, respectively.

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.

Anti-HIV-1 constituents from Clausena excavata: Part II. Carbazoles and a pyranocoumarin.

Three carbazole derivatives, O-methylmukonal (1), 3-formyl-2,7-dimethoxycarbazole (2) and clauszoline J (3), and a pyranocoumarin, clausenidin (4), were isolated from the rhizomes and roots of Clausena excavata. Compound 1, isolated from this plant for the first time, has not been reported previously as having anti-HIV-1 activity. Compounds 1-4 displayed anti-HIV-1 activity in a syncytial assay with EC(50) values of 12, 29.1, 34.2 and 5.3 microm, respectively, and thus exhibited potential therapeutic index (PTI) values of 56.7, 8.0, 1.6 and 7.0, respectively. All isolated compounds demonstrated a lack of cytotoxicity against the KB and BC-1 cancer cell lines.

Anti-HIV-1 cycloartanes from leaves and twigs of Gardenia thailandica.

Thailandiol ( 1), gardenolic acid A ( 2), quadrangularic acid E ( 3) and 3beta-hydroxy-5alpha-cycloart-24(31)-en-28-oic acid ( 4) have been isolated from the leaves and twigs of Gardenia thailandica Tirveng (order: Rubiales; family: Rubiaceae). In addition, 5-hydroxy-7,2',3',4',5',6'-hexamethoxyflavone ( 5), 5,7-dihydroxy-2',3', 4',5',6'-pentamethoxyflavone ( 6), 5-hydroxy-7,2',3',4',5'-pentamethoxyflavone ( 7) and 5,7-dihydroxy-2',3',4',5'-tetramethoxyflavone ( 8) were also isolated from the same source. The structures were elucidated by spectroscopic methods. Crude extracts and compounds 1 - 4 displayed anti-HIV-1 activities as determined by using the (Delta)(Tat/Rev)MC99 virus and 1A2 cell line system. The EC (50) values determined by the syncytium assay ranged from < 7.8 to 110 microg/mL. They also exhibited moderate to high activities in reverse transcriptase (RT) assay; the IC (50) values of compounds 1 - 4, ranged from < 22.5 to 156.8 microg/mL.

Anti-HIV-1 limonoid: first isolation from Clausena excavata.

A limonoid, clausenolide-1-ethyl ether (1) and two coumarins, dentatin (2) and nor-dentatin (3), were isolated from Clausena excavata. Limonoid 1 was obtained from the crude ethanol extract of the rhizomes and the roots but had not previously been isolated from C. excavata and exhibited HIV-1 inhibitory activity. Coumarins 2 and 3, with their structures related to an anti-HIV-1 substance, (+)-calanolide A (4), were obtained from the crude chloroform extract of the rhizomes. Both induced toxicity to cells used in a syncytium assay for anti-HIV-1 activity. These compounds, 1-3, did not show any cytotoxic effect against KB and BC-1 cell lines (IC(50) value > 20 microgram/mL).

Anti-HIV-1 protostane triterpenes and digeranylbenzophenone from trunk bark and stems of Garcinia speciosa.

Three new protostanes, garciosaterpenes A ( 1), B ( 2) and C ( 3), together with a new digeranylbenzophenone, garciosaphenone A ( 4) were isolated from the ethyl acetate fractions obtained from the crude methanol extracts of the trunk bark and stems of Garcinia speciosa. The structures were elucidated by spectroscopic methods and chemical reactions. Compounds 1 and 3 showed significant inhibitory activities (IC (50) 15.5 and 12.2 microg/mL, respectively) against HIV-1 reverse transcriptase and in the syncytium assay (EC (50) 5.8 microg/mL with TI 3.4 and 37.0 microg/mL with TI 1.9, respectively). Compound 4 was active in HIV-1 RT assay (IC (50) 23.9 microg/mL), but toxic in the syncytium assay. This work represents the first report on the anti-HIV-1 activities of the protostane triterpenes.