Nguyen Thi Nga

Synthesis and anti-proliferative activity of novel azazerumbone conjugates with chalcones

The conjugation of azazerumbone ((3E,7E,11E)-5,5,8,12-tetramethylazacyclododeca-3,7,11-trien-2-one (7)) and 2,4-dihydroxychalcones was carried out for the preparation of novel target compounds 9a-g with 1-ethylene-4-methylene-1,2,3-triazole linker and 10a-f with propylene linker between amide nitrogen of azazerumbone and 4-hydroxy group of chalcone. The anti-proliferative activity of these compounds against the LU-1, Hep-G2, MCF-7 and SW480 human cancer cell lines were significantly improved compared to those of azazerumbone or zerumbone. The anti-proliferative activities of (3E,7E,11E)-1-((1-(2-(3-hydroxy-4-((E)-3-(3-methoxyphenyl)acryloyl)phenoxy)ethyl)-1H-1,2,3-triazol-4-yl)methyl)-5,5,8,12-tetramethyl azacyclododeca-3,7,11-trien-2-one (9b) and (3E,7E,11E)-1-(3-(4-((E)-3-(3,4,5-trimethoxyphenyl)acryloyl)phenoxy)propyl)-5,5,8,12-tetramethylazacyclododeca-3,7,11-trien-2-one (10d) are nearly comparable to those of ellipticine.

The hepatoprotective activity of a new derivative kaempferol glycoside from the leaves of Vietnamese Phyllanthus acidus (L.) Skeels

A new derivative kaempferol glycoside, kaempferol-3-O-(2-α-l-rhamnopyranosyl)-β-d-glucuronopyranosyl methyl ester (3), together with six other known kaempferol glycosides, kaempferol-3-O-[α-l-rhamnopyranosyl (1→2)]-β-d-galactopyranoside (1), kaempferol-3-O-(2-α-l-rhamnopyranosyl)-β-d-glucuronopyranoside (2), rutin (4), isoquercitrin (5), quercitrin (6), and myricitrin (7) were isolated from the leaves of Phyllanthus acidus (L.) Skeels (Phyllanthaceae). Here, is the first report described the isolation of compound (1) and (2) from the genus Phyllanthus. Compound (1) presents antioxidant activity in 2,2-diphenyl-1-picryl-hydrazyl-hydrate assay. Compound (2) and (3) performed no antioxidant activity in 2,2-diphenyl-1-picryl-hydrazyl-hydrate and thiobarbituric acid reactive substances assays (IC50 > 100 µM). However, compound (2) showed anti-inflammation activity through inhibiting interleukin 6 and tumor necrosis factor alpha production (P < 0.05). Compound (3) also exhibited cytokine modulating activities such as inhibiting tumor necrosis factor alpha, activating interleukin 10 at concentration of 10 µM (P < 0.05). The interleukin 6 cytokine level was also up or down-regulated by compound (3) at two time points; 24 and 48 h. This activeness of compound (3) might induce hepatoprotection in the acute-phase response by activating the signal transducer and activator of transcription 3(STAT3) through cytokine modulation. Together with other kaempferol glycosides, this new derivative compound may mediate the liver-protective activity of the Vietnamese medicinal plant Phyllanthus acidus.

Synthesis and Antimicrobial Activity of Chalcones Containing Benzotriazolylmethyl and Imidazolylmethyl Substituents

Methods have been developed for the synthesis of new 1H-benzotriazol-1-ylmethyl- and 1H-imidazol-1-ylmethyl-substituted chalcones starting from 2-hydroxyacetophenone. The procedures include chloromethylation, N-alkylation, and Claisen-Schmidt condensation. The presence of an imidazole fragment on the ring A and piperazine fragment on the ring B of the resulting chalcones increases their antimicrobial activity (minimum inhibitory concentration 12.5–50.0 μg/mL), whereas introduction of a benzotriazole fragment reduces the antimicrobial activity.

INVESTIGATING THE ANTI-INFLAMMATORY ACTIVITY OF AN ETHANOLIC EXTRACT FROM ARTOCARPUS TONKINENSIS LEAVES USING A COLLAGEN ANTIBODY-INDUCED ARTHRITIC MOUSE MODEL

This study was contrived for evaluating the in vitro and in vivo anti-inflammatory effects of an aqueous ethanolic leaf extract of the Vietnamese Artocarpustonkinensis A. Chev. exGagnep. usinglipopolysaccharide-stimulated RAW 264.7 macrophages and a collagen antibody-induced arthritic mouse model as well. The obtained results here demonstrate that the 70 % ethanolic leaf extract of A. tonkinensis(AT2), traditionally used in Vietnamese folk medicine for treating arthritic symptoms, has beneficial effects on pro-inflammatory cytokine inhibition and in an experimental arthritic mouse model.LPS-stimulated RAW 264.7 macrophages treated with AT2 showed a significant decrease in the production of IL-6 and TNF at concentrations of 12.5, 25 and 50 μg/mL (P < 0.05), indicating its potential anti-inflammatory properties. The treatment of CAIA mice with AT2 also led to diminish the incidence of arthritis at doses of 200 and 300 mg/kg body weight.

Chemical constituents of Oldenlandia pinifolia and their antiproliferative activities

Abstract This study describes the chemical constituents of Oldenlandia pinifolia (Wall. Ex G. Don) Kuntze (synonym Hedyotis pinifolia Wall. Ex G. Don) and discusses their anti-proliferative activities. Thirteen compounds were isolated from the n-hexane, ethyl acetate and n-butanol extracts of whole plants O. pinifolia by chromatography method. Their structures were elucidated using MS and NMR analysis and compared with reported data. They are three anthraquinones, a carotenoid, two triterpenes, four iridoid glycosides and three flavonoid glycosides. Among them, 2-methyl-1,4,6-trihydroxy-anthraquinone is a new one, and three compounds were found for the first time in this genus. MTT assay resulted that the n-butanol extract and four isolated compounds inhibited the proliferation of chronic myelogenous leukaemia cells. The results from Hoechst 33343 staining and caspase 3-inducing exhibited that those four tested compounds induced apoptosis and activated caspase 3 (p < 0.05). One of them, isorhamnetin-3-O-β-rutinoside showed the most activity with IC50 value of 394.68 ± 25.12 μM.

The in vitro and in vivo anti-inflammatory activities of alphitonin-4-O-β-D-glucopyranoside

Abstract The anti-inflammatory compound, alphitonin-4-O-β-D-glucopyranoside (1), has previously been isolated in the leaves of Artokapus tonkinensis and synthesised from taxifolin. This study aimed to investigate the inhibitory effect of this compound on inflammatory cytokines, including tumour necrosis factor-alpha (TNF-α), interleukin (IL)-1, IL-6 and IL-10, in RAW264.7 macrophages and in an arthritis animal model. Compound 1 dose-dependently decreased the production of TNF-α, IL-1 and IL-6 in lipopolysaccharide-stimulated RAW264.7 cells. In contrast, the level of anti-inflammatory IL-10 increased. In a collagen antibody-induced arthritis BALB/c mouse model, compound 1 at a dose of 125 and 250 mg/kg body weight significantly decreased arthritis incidence in comparison with dexamethasone.

Evaluation of biological activities of polysaccharides and compounds isolated from Lentinus edodes

Two polysaccharide samples (Poly1 and Poly2) and three compounds (galactiol, ergosterol and ergosterol peroxide) were isolated from the fruiting body of Lentinus edodes . Poly1 and ergosterol peroxide (NH-3) showed cytotoxicities against two liver cancer cell lines Hep-G2 (Hepatocellular carcinoma) and RD (Rhabdomyosarcoma) with IC 50 values of 29.62 and 34.24; 3.84 and 7.61 mg/mL respectively. Poly1 and NH-3 showed capacities for decreasing Hep-G2 tumor density by 54.09 and 58.33%, respectiviely in comparison to the control. In addtion, the average sizes of tumors treated with Poly1 and NH-3 were decreased by 35.36 and 55.18%, respectively as compared to the control.