Waya S. Phutdhawong

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 RAW264.7 murine macrophages. The results showed that most of the tested compounds inhibit the production of nitric oxide (NO), prostaglandin (PG)E(2), tumour necrosis factor (TNF)-alpha, interleukin (IL)-6 and IL-1beta in RAW264.7 cells treated with LPS.

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 IC50 = 3.5 μg/mL and 3.0 μg/mL, respectively.

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.

Antibacterial and Anticandidal Activities of New Flavonoids from Streptomyces sp. HK17; an Endophyte in Curcuma longa Linn

Aims: The purpose of this study was to investigate the antibacterial and anticandidal activities of new flavonoids from Streptomyces sp. HK17 which was isolated from the root tissue of Curcuma longa Linn.

Antibacterial, antioxidant and anticancer activities of biphenyls from Streptomyces sp. BO-07: an endophyte in Boesenbergia rotunda (L.) Mansf A.

ABSTRACT Strain BO-07 was isolated from the root tissue of Boesenbergia rotunda (L.) Mansf A. and identified as Streptomyces sp. on the basis of morphology, chemotaxonomy and 16S rDNA sequencing. The fractionation of the crude extract from strain BO-07 cultures led to the isolation of two biphenyls: 3′-hydroxy-5-methoxy-3,4-methylenedioxybiphenyl (1) and 3′-hydroxy-5,5′-dimethoxy-3,4-methylenedioxybiphenyl (2); these compounds and the crude extract had potent antibacterial activity against Gram-positive bacteria, and antioxidant and anticancer activities. These compounds showed the highest activity against Staphylococcus aureus ATCC25932, Bacillus cereus ATCC7064 and Bacillus subtilis ATCC6633 with a minimum inhibitory concentration value of 0.5 µg/ml and minimum bactericidal concentration of 2–8 µg/ml. Compounds 1 and 2 showed the highest (1, 1diphenyl-2-picryl hydrazyl) DPPH antioxidant activity with a scavenging concentration (SC50) value of 85.84 and 88.26 µg/ml, respectively, and also showed strong cytotoxicity against all the three cancer cell lines (HeLa, HepG2 and Huh7) at an IC50 value of 3.04–20.30 μg/ml. Both the compounds were less toxic on normal cells (L929) than on the investigated cancer cell lines.

Antibacterial and Antioxidant Activities of Acetogenins from Streptomyces sp. VE2; An Endophyte in Vernonia cinerea (L.) Less. -

Strain VE2 was isolated from the stem tissue of Vernonia cinerea (L.) Less. and identified as Streptomyces sp. on the basis of morphology, chemotaxonomy and 16SrDNA sequencing. The fractionation of the crude ethyl acetate (CEA) extract from VE2 cultures led to the isolation of two acetogenins; squamocin and rollidecin B; these compounds and CEA extract had potential in antibacterial and antioxidant activities. The crude extract showed the highest activity against Salmonella Typhi ATCC19430 and Bacillus cereus ATCC7064, with MIC values of 32 µg/ml. Squamocin also showed the lowest MIC (32 µg/ml) and Minimum Bactericidal Concentration (MBC) (128 µg/ml) against S. Typhi and B. cereus with corresponding large diameter of the zone of inhibitions (27.5 and 28.2 mm, respectively). Rollidecin B showed the highest DPPH antioxidant activity with SC50 value of 58.92 µg/ml.

Anti-Inflammatory Effects of New Flavonoids from Streptomyces sp. BT01 in Lipopolysaccharide-Stimulated RAW 264.7 Murine Macrophages via Inhibition of NF-KappaB Activation

Most flavonoids are known to have anti-oxidant, anti-bacterial and analgesic properties. In this study, the new flavonoids, 7-methoxy-3,3’,4’,6-tetrahydroxyflavone (1) and 2’,7dihydroxy-4’5’-dimethoxyisoflavone (2) isolated from Streptomyces sp. BT01 inhibited the pro-inflammatory mediators including cytokines by blocking nuclear factor-kappaB (NFκB) signalling in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. These flavonoids suppressed mRNA and protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in LPS-stimulated RAW 264.7 cells. The molecular mechanism was associated with the inhibition of NF-κB activation. These results suggest that these flavonoids have anti-inflammatory effects by suppressing expression of Original Research Article British Journal of Applied Science & Technology, 4(29): 4201-4222, 2014 4202 iNOS, COX-2 and cytokines by blocking the NF-κB signalling in LPS-stimulated RAW 264.7 cells.