Electrocoagulation is an electrochemical technique with many applications, in which a variety of unwanted dissolved particles and suspended matter can be effectively removed from an aqueous solution by electrolysis. Thus, for example, it is used to clarify food wastewater, 1 tar-sand and oil-shale wastewater, 2 as well as potable water. 3 It can remove phosphate from sewage, 4,5 cyanide and chromate from industrial wastewater, 6 and fluoride from drinking water. 7 Several heavy metal ions can also be efficiently removed from industrial waste. 8,9 Electrocoagulation can also be used to decolorize dyecontaining solutions, such as textile wastewater 10,11 and crude aqueous plant extracts. 12-17The main advantages of the electrocoagulation method over coagulation by the addition of chemicals, such as salts of aluminium and iron, are simple equipment and easy operation, a shortened reactive retention period, a reduction or absence of equipment for adding chemicals, and a decreased amount of precipitate or sludge. Moreover, and perhaps most important of all, during electrocoagulation the liquid is not enriched with anions, and its salt content does not increase, as is the case of a chemical treatment. 6 In this study, we decided to investigate the electrocoagulation of certain phenolic compounds in a systematic manner, in view of the fact that phenolic substances often occur in many industrial wastes, especially textile and paper mill effluents, and also in many plant extracts, e.g. flavonoids and tannins. Additionally, we also report on a simple method for recovering these phenolic substances from coagulated sludge. ExperimentalTwo aluminium plates (dimension 30 × 10 × 0.05 cm) were used as electrodes. These were dipped 3 cm apart and 9 cm deep into a magnetically-stirred aqueous solution (1 litre) of a phenolic compound (0.1% w/v) in a glass jar (diameter 11 cm, height 23 cm). Sodium chloride (2 g) was added as an electrolyte. Direct current (0.5 A, 22 V) from a DC power supplier was then passed through the solution via the two electrodes. At every 15-min interval during a 2-h period of electrolysis, a 10-cm 3 aliquot sample of the solution was drawn, filtered, and taken for an absorbance measurement at an appropriate wavelength of the absorption maximum for each phenolic compound, as follows: phenol 250, resorcinol 272, pyrocatechol 252, pyrogallol 243, phloroglucinol 233, n-propyl 3,4,5-trihydroxybenzoate 243, orcinol 241, hydroquinone 243, and tannin 242 nm. The measured absorbance was then converted to the residual weight percentage of the compound by a calibration curve obtained from a plot between the absorbance versus the concentration for each compound. All of the phenolic compounds used were of standard reagent grade, and were used as such.Phenol and resorcinol (1,3-dihydroxybenzene) were purchased from Fluka Chemie AG, Buchs, Switzerland; pyrocatechol (1,2-dihydroxybenzene) and pyrogallol (1,2,3-trihydroxybenzene) were purchased from E. Merck, Darmstadt, Germany; phloroglucinol (1,3,5-trihydroxybenzene) an...

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-3,4methylenedioxybiphenyl (1) and 3 ′-hydroxy-5,5 ′-dimethoxy-3,4methylenedioxybiphenyl (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 (SC 50) 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 IC 50 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.

Streptomyces zerumbet W14, a novel species of the endophyte genus Streptomyces was isolated from the rhizome tissue of Zingiber zerumbet (L.) Smith. Identification of strain W14 was based on its morphology, chemotaxonomy and phylogenetic analysis using 16S rDNA sequence. It was classified as the secondary meabolites of the culture extract were studied. The major active ingredients from the crude extract were purified by silica gel column chromatography and identified by spectroscopic data. The crude extract and purified compounds were tested for their biological activities on antibacterial and anti-inflammatory properties. The crude extract showed inhibition on the growth of Gram-positive bacteria with the MIC and MBC values of 8-32 µg/ml and 32-128 µg/ml, respectively. The isolated compounds were identified to be methyl 5-(hydroxymethyl)furan-2-carboxylate (1) and geldanamycin (2). Bioassay studies showed that compound 1 had antibacterial activity against Staphylococus aureus ATCC 25923 and Methicillin Resistant S. aureus strain Sp6 (clinical isolate) with the MIC and MBC values of 1 µg/ml and 16-64 µg/ml, respectively, and also showed activity against Bacillus Calmette-Guérin (vaccine strain) with MIC and MBC values of 128.00 µg/ml and 128.00 µg/ml, respectively. The compound 2 at the concentration of 1-5 µg/ml had in vitro anti-inflammatory activity on LPS-induced RAW 264.7 cells by inhibition of mRNA expression and production of inducible NO synthase (iNOS), tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6). These results suggest that compounds 1 and 2 produced by S. zerumbet W14 (an endophyte of Z. Zerumbet) have antibacterial and anti-inflammatory activities, respectively. Therefore, the future studies on these compounds could be useful for the management of bacterial infections and inflammatory diseases.

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 (14b and 14e, respectively) were found to be the most potent derivatives against HepG2 cancer cell lines (IC50 = 2.62–4.85 μM) and HeLa cancer cell lines (IC50 = 0.39–0.75 μM). The activities of these two compounds were comparable to that of the positive control doxorubicin; especially, 4-flurobenzamide derivative (14b) exhibited low cytotoxic activity against LLC-MK2 normal cell lines, with IC50 more than 100 μM. The molecular docking study of the synthesized compounds revealed the binding to the active site of the CK2 enzyme, indicating that the presence of the benzamide functionality is an important feature for anticancer activity.

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. The composition of the oil from both methods was found to be similar, and (-)-linalool was found as the main component (30-50 %). The antioxidant activity of the essential oil obtained by both methods was evaluated using DPPH, ABTS, FRAP and lipid peroxidation methods, all of which indicated the same but insignificant activity.