Dan Thi Thuy Hang

Anti-inflammatory effects of fatty acids isolated from Chromolaena odorata

OBJECTIVE To identify inhibitors of nitric oxide production and NF-κB activity from Chromolaena odorata (C. odorata). METHODS The compounds isolated from the aerial parts of C. odorata by bioassay-guided fractionation were investigated for their inhibitory effects on the NO production and NF-κB activity in LPS-stimulated RAW264.7 cells. RESULTS Six fatty acids (S)-coriolic acid (1), (S)-coriolic acid methyl ester (2), (S)-15,16-didehydrocoriolic acid (3), (S)-15,16-didehydrocoriolic acid methyl ester (4), linoleamide (5) and linolenamide (6) were isolated. All compounds inhibited the NO production at concentrations consistent with those required for NF-κB inhibition. Compound 2 was the most active with the IC(50) values of 5.22 and 5.73 μM. The addition of a double bond in the fatty chain decreased the inhibitory effects while the methyl esterification increased the activities. CONCLUSIONS The fatty acid components in C. odorata with NF-κB inhibitory activity could explain the anti-inflammation property of this plant in traditional medicine. This study could also contribute to the better use of C. odorata for human health care.

New ent-kauranes from the fruits of Annona glabra and their inhibitory nitric oxide production in LPS-stimulated RAW264.7 macrophages

Three new ent-kaurane diterpenoids, 7β,16α,17-trihydroxy-ent-kauran-19-oic acid (1), 7β,17-dihydroxy-16α-ent-kauran-19-oic acid 19-O-β-d-glucopyranoside ester (2), 7β,17-dihydroxy-ent-kaur-15-en-19-oic acid 19-O-β-d-glucopyranoside ester (3) along with five known compounds, paniculoside IV (4), 16α,17-dihydroxy-ent-kaurane (5), 16β,17-dihydroxy-ent-kaurane (6), 16β,17-dihydroxy-ent-kauran-19-al (7), and 16β,17-dihydroxy-ent-kauran-19-oic acid (8) were isolated from the fruits of Annona glabra. Their chemical structures were elucidated by physical and chemical methods. All compounds were evaluated for inhibitory activity against nitric oxide (NO) production in LPS-stimulated RAW 264.7 macrophages. As the results, compound 3 showed potent inhibitory LPS-stimulated NO production in RAW 264.7 macrophages with the IC50 value of 0.01±0.01μM; compounds 1 and 7 showed significant inhibitory NO production with the IC50 values of 0.39±0.12μM and 0.32±0.04μM, respectively.

Chemical constituents of the Annona glabra fruit and their cytotoxic activity

Abstract Context: Traditional Chinese medicines have attracted increasing interest as potential sources of novel drugs with a wide range of biological and pharmacological activities. Annona glabra Linn (Annonaceae) is used in traditional medicine as an anticancer drug. Phytochemical investigation of this plant led to the isolation of acetogenins, ent-kauranes, peptides, and alkaloids. In addition, compounds exhibited anticancer, anti-HIV-reserve, and antimalaria. Objective: Isolation, structure determination, and cytotoxic activity evaluation of compounds from the methanol extract from A. glabra fruits. Materials and methods: Using chromatographic methods to isolate compounds from the A. glabra methanol extract. The cytotoxic activity of compounds was evaluated by a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. In addition, compounds which showed significant cytotoxic activity were chosen for further study apoptosis characteristics. Results: One new, (2E,4E,1′R,3′S,5′R,6′S)-dihydrophaseic acid 1,3′-di-O-β-d-glucopyranoside, and eight known compounds, (2E,4E,1′R,3′S,5′R,6′S)-dihydrophaseic acid 3′-O-β-d-glucopyranoside (2), icariside D2 (3), icariside D2 6′-O-β-d-xylopyranoside (4), 3,4-dimethoxyphenyl O-β-d-glucopyranoside (5), 3,4-dihydroxybenzoic acid (6), blumenol A (7), cucumegastigmane I (8), and icariside B1 (9), were isolated from the fruits of A. glabra. Icariside D2 (3) was found to show significant cytotoxic activity on the HL-60 cell line with the IC50 value of 9.0 ± 1.0 µM and did not show cytotoxic activity on the Hel-299 normal cell line. The further test indicated that compound 3 induced apoptosis via alteration of expression of apoptosis-related proteins and decreased phosphorylation of AKT in HL-60 cells. Discussion and conclusion: The results suggested that the constituents from A. glabra may contain effective compounds which can be used as anticancer agents.

1)H and (13)C NMR assignments of sesquiterpenes from Dysidea fragilis.

Sesquiterpenes have been reported as components of the genus Dysidea (Dysideidae). Many chemical investigations have been focused on the marine sponge Dysidea fragilis. The constituents of D. fragilis were identified as sesquiterpenes, steroids and diketopiperazines. They exhibited various biological activities such as anti-inflammatory and cytotoxic activities. Previously, series of new sesquiterpenes were reported from the Vietnamese sponge D. cinerea by our group. In continuing research on bioactive compounds from genus Dysidea, three new and two known sesquiterpenes were isolated from the sponge D. fragilis. Herein, we report the isolation and structure elucidation of these compounds.

Naphtoquinones and Sesquiterpene Cyclopentenones from the Sponge Smenospongia cerebriformis with Their Cytotoxic Activity

Two new naphtoquinones (smenocerones A and B, 1 and 2) and four known sesquiterpene cyclopentenones (dactylospongenones A-D, 3-6) were isolated from sponge Smenospongia cerebriformis living in the Eastern Sea of Vietnam. Their chemical structures were determined by high resolution electrospray ionization (HR-ESI)-MS, NMR spectroscopic analysis, and in comparison with the reported data. The chiroptical properties of compounds 3-6 were examined by experiment and theoretical calculation of circular dichroism (CD) spectra to prove their absolute configurations. Compound 2 significantly exhibited cytotoxic activity towards lung carcinoma (LU-1), hepatocellular carcinoma (HepG-2), promyelocytic leukemia (HL-60), breast carcinoma (MCF-7), and melanoma (SK-Mel-2) human cancer cells with IC50 values of 5.5±0.8, 3.2±0.2, 4.0±0.7, 4.1±0.8, and 5.7±1.1 µg/mL, respectively.

1H and 13C NMR assignments of new ecdysteroids from Callisia fragrans

Ecdysteroids are a class of insect hormones with a characteristic 7en-6-one moiety in the B-ring of polyhydroxysteroids. They were discovered as insect molting hormones. These compounds display important physiological effects on insects and play defensive role. Ecdysteroids also exert beneficial pharmacological properties such as decreasing the blood cholesterol and glucose level in experimental animals, anticancer, and wound healing activities. The increasing numbers of patents have been deposited concerning various beneficial effects of ecdysteroids in many medical or cosmetic domains, whichmake ecdysteroids very attractive candidates for several practical uses. Callisia fragrans (Lindl.) belongs to Commelinaceae family and is native in South America. Chemical studies of this plant showed the presence of phenolic compounds and amino acids. In addition, the methanol extract of C. fragrans showed antiherpetic activity. In this paper, we report the isolation and structure determination of three new and two known ecdysteroids from the stems of C. fragrans.

Macrocyclic bis-quinolizidine alkaloids from Xestospongia muta

Abstract A new stereoisomer Meso-araguspongine C together with nine reported macrocyclic bis-quinolizidine alkaloids araguspongines A, C, E, L, N−P, petrosin, and petrosin A were isolated from marine sponge Xestospongia muta. Stereochemistry of meso-araguspongine C (2) and araguspongines N-P (3−5) were established by their NMR data and conformational analyses. Both araguspongine C (1) and meso-araguspongine C (2) exhibited great cytotoxic activity towards HepG-2, HL-60, LU-1, MCF-7, and SK-Mel-2 human cancer cells (IC50 in the range of 0.43–1.02 μM). At a concentration of 20 μM, isolated compounds (1−10) also showed modest inhibitory effects (from 7.6 to 40.8%) on the NO production in LPS activated RAW264.7 macrophages.

Merosesquiterpenes from marine sponge Smenospongia cerebriformis

Using various chromatography methods, three merosesquiterpenes belonging to sesquiterpene quinone type, neodactyloquinone ( 1 ), dactyloquinone D ( 2 ), and dactyloquinone C ( 3 ) together with two indole derivatives indole-3-aldehyde ( 4 ) and indole-3-cacboxylic methyl ester ( 5 ) were isolated from the methanol extract of the Vietnamese marine sponge Smenospongia cerebriformis . Their structures were determined by 1D-, 2D-NMR spectra, HR-ESI-MS and in comparison with those reported in the literature. Keywords. Smenospongia cerebriformis , merosesquiterpene, sesquiterpene quinone, indole derivative.

Sesquiterpene phenols from marine sponge Smenospongia cerebriformis.

Using various chromatography methods, four sesquiterpene phenols, dictyoceratin C ( 1 ), polyfibrospongol A ( 2 ), polyfibrospongol B ( 3 ), and 19-hydroxy-polyfibrospongol B ( 4 ) were isolated from the methanol extract of the Vietnamese marine sponge Smenospongia cerebriformis . Their structures were determined by 1D-, 2D-NMR spectra, HR-ESI-MS and in comparison with those reported in the literature. Keywords . Smenospongia cerebriformis , sponge, sesquiterpene phenol.

Sterols from the sponge Haliclona varia.

Using combined chromatographic methods, four sterols, 3 β -hydroxycholest-5-en-7-one ( 1 ), 22( E )-3 β -hydroxycholesta-5,22-dien-7-one ( 2 ), 3 β ,7 α -dihydroxycholest-5-ene ( 3 ), and 3 β ,7 β -dihydroxycholest-5-ene ( 4 ) were isolated from the methanol extract of the sponge Haliclona varia . Their structures were elucidated by 1D and 2D-NMR spectroscopic methods as well as in comparison with the previous literature. Compounds 2-4 were reported from the genus Haliclona for the first time. Keywords. Haliclona varia , sponge, sterol.