2,5-Diketopiperazine Derivatives as Potential Anti-Influenza (H5N2) Agents: Synthesis, Biological Evaluation, and Molecular Docking Study.

2,5-Diketopiperazine derivatives, consisting of benzylidene and alkylidene substituents at 3 and 6 positions, have been considered as a core structure for their antiviral activities. Herein, the novel -substituted 2,5-Diketopiperazine derivatives were successfully prepared and their antiviral activities against influenza virus were evaluated by monitoring viral propagation in embryonated chicken eggs. It was found that (3,6)-3-benzylidene-6-(2-methyl propylidene)-4-substituted-2,5-Diketopiperazines (), (3,6)-3-benzylidene-6-(2-methylpropyli dene)-1-(1-ethyl pyrrolidine)-2,5-Diketopiperazine (), and Lansai-C exhibited negative results in influenza virus propagation at a concentration of 25 µg/mL.

Synthesis and Biological Activity Evaluation of Coumarin-3-Carboxamide Derivatives.

A series of novel coumarin-3-carboxamide derivatives were designed and synthesized to evaluate their biological activities. The compounds showed little to no activity against gram-positive and gram-negative bacteria but specifically showed potential to inhibit the growth of cancer cells. In particular, among the tested compounds, 4-fluoro and 2,5-difluoro benzamide derivatives ( and , respectively) were found to be the most potent derivatives against HepG2 cancer cell lines (IC = 2.

Synthesis and Investigation of Tetrahydro-β-carboline Derivatives as Inhibitors of Plant Pathogenic Fungi.

A series of tetrahydro-ß-carbolines substituted with an alkyl or acyl side chain was synthesized and screened for its antifungal activity plant pathogenic fungi (, , and ). The structure activity relationship revealed that the substituent at the piperidine nitrogen plays an important role for increasing antifungal activities. In this series, 2-octyl-2,3,4,9-tetrahydro-1-pyrido[3,4-]indole () displayed potent antifungal activities with a minimum inhibitory concentration of 0.

Synthesis and preliminary evaluation of dimeric-28-homobrassinosteroids for plant growth regulators.

Preparation of synthetic analogues of 28-homobrassinosteroids is reported. Also, the addition of the 28-homocastasterone at the C6 carbonyl group via allyl Gringard reagent followed by olefin cross metathesis resulted in dimeric analogues. Rice lamina inclination assay showed that the replacement of the C6 carbonyl group by 6α-allyl and 6β hydroxyl groups led to a decrease in bioactivity, whereas the dimeric analogues showed a reduced but significant bioactivity when compared to the 28-homocastasterone.

Synthesis and anticancer activity of 5,6,8,13-tetrahydro-7H-naphtho[2,3-a][3]-benzazepine-8,13-diones.

A series of naphthoquinones fused benzazepines, 5,6,8,13-tetrahydro-7H-naphtho[2,3-a][3]-benzazepine-8,13-diones, were synthesized and evaluated for their anticancer activity against four cell lines; human breast carcinoma cell line, human cervix carcinoma cell line, human hepatocellular carcinoma cell line and human keratinocyte cell line. The results showed that 5,6,8,13-tetrahydro-2,3,4,9-tetramethoxy-7H-naphtho[2,3-a][3]benzazepine-8,13-dione 4g and 5,6,8,13-tetrahydro-2,3,9-trimethoxy-7H-naphtho[2,3-a][3]benzazepine-8,13-dione 4h have significant cytotoxicity against a hepatocellular carcinoma cell line with IC(50) = 3.5 μg/mL and 3.

Synthesis of 1,6,7,8-tetrahydro-naphtho[2,3-d]-azepino[4,5-b]indole-9,14-diones and their inhibitory effects on pro-inflammatory cytokines.

A rapid route to a series of naphthoquinone-fused indole derivatives via irradiation in a modified commercial domestic microwave is reported. The desired products were produced in high yields and short reaction times. The naphthoquinone-fused indole derivatives were evaluated for their pro-inflammatory cytokines responses using lipopolysaccharide (LPS)-stimulated RAW264.

Electrocoagulation of palm oil mill effluent.

Electrocoagulation (EC) is an electrochemical technique which has been employed in the treatment of various kinds of wastewater. In this work the potential use of EC for the treatment of palm oil mill effluent (POME) was investigated. In a laboratory scale, POME from a factory site in Chumporn Province (Thailand) was subjected to EC using aluminum as electrodes and sodium chloride as supporting electrolyte.

Facile microwave-assisted synthesis of 9,10-dihydro-9,10-ethanoanthracene-11-carboxylic acid methyl ester.

A facile, high yielding synthesis of 9,10-dihydro-9,10-ethano- anthracene-11- carboxylic acid methyl ester using a modified commercial domestic microwave oven is reported.

Electrocoagulation of quinone pigments.

Some representative quinones, viz. one naphthoquinone (plumbagin) and five anthraquinones (alizarin, purpurin, chrysazin, emodin, and anthrarufin), were subjected to electrocoagulation. It was found that the rate and extent of coagulation of these compounds appears to correlate with the number and relative position of their phenolic substituent groups, and that all of the coagulated quinones could be recovered.

Dechlorophyllation by electrocoagulation.

Electrocoagulation was used for dechlorophyllation of alcoholic extracts from five plants. The results showed that for every plant extract studied, electrocoagulation was more efficient than the classical solvent extraction method in removing plant pigments, while not affecting the important secondary metabolites in those extracts.

Solvent effects in electrocoagulation of selected plant pigments and tannin.

Electrocoagulation of a plant extract and certain substances representative of selected classes of plant pigments, viz. chlorophyll, a carotenoid, a phenolic substance and a tannin, was performed in ethanol containing varying amounts of water (15-75%). The results showed that the extent and efficiency of coagulation of these substances tends to vary in a manner directly related to the water content of the solvent, although the tannin and the phenolic substance were less sensitive to the solvent composition and are equally well coagulated in all solvent systems studied.

Microwave-assisted isolation of essential oil of Cinnamomum iners Reinw. ex Bl.: comparison with conventional hydrodistillation.

Microwave-assisted hydrodistillation was used to isolate an essential oil from the leaves of Cinnamomum iners Reinw. ex Bl., and the results compared with those obtained by conventional hydrodistillation.