Insights into the prostanoid pathway in the ovary development of the penaeid shrimp Penaeus monodon.

The prostanoid pathway converts polyunsaturated fatty acids (PUFAs) into bioactive lipid mediators, including prostaglandins, thromboxanes and prostacyclins, all of which play vital roles in the immune and reproductive systems in most animal phyla. In crustaceans, PUFAs and prostaglandins have been detected and often associated with female reproductive maturation. However, the presence of prostanoid biosynthesis genes remained in question in these species.

Sphaerisporangium krabiense sp. nov., isolated from soil.

A Gram-staining-positive, filamentous bacterial strain, designated A-T 0308(T), was isolated from soil of a tropical mangrove forest in Thailand. Strain A-T 0308(T) developed spherical sporangia containing non-motile spores on aerial mycelium. The novel strain contained meso-diaminopimelic acid, N-acetyl-type peptidoglycan and madurose, mannose, ribose, galactose and glucose as whole-cell sugars.

Cyclohexene, diketopiperazine, lactone and phenol derivatives from the sea fan-derived fungi Nigrospora sp. PSU-F11 and PSU-F12.

Nigrosporanenes A (1) and B (2), two new cylohexene derivatives, and tyrosol (3) were isolated from the sea fan-derived fungus Nigrospora sp. PSU-F11, whereas five known compounds: 4-hydroxybenzoic acid (4), aplysiopsene D (5), 3-isochromanone (6), (-)-drimenin (7) and diketopiperazine derivative (8), were obtained from the fungus Nigrospora sp. PSU-F12.

An [11]cytochalasin derivative from the marine-derived fungus Xylaria sp. PSU-F100.

A new [11]cytochalasin derivative, xylarisin (1), was isolated from the marine-derived fungus Xylaria sp. PSU-F100 along with six known metabolites: three mellein derivatives (2-4), one pyrone derivative (5) and two carboxylic acids (6,7). The structure and stereochemistry of 1 were determined by NMR and X-ray diffraction analyses.

Planotetraspora kaengkrachanensis sp. nov. and Planotetraspora phitsanulokensis sp. nov., isolated from soil.

Two novel bacterial strains were isolated from tropical rain forest soil from Thailand. Strains A-T 0875(T) and A-T 1383(T) stained Gram-positive and were filamentous bacteria that developed cylindrical sporangia containing four oval- to rod-shaped spores at the ends of short sporangiophores on branched aerial mycelium. The cell-wall peptidoglycan contained meso-diaminopimelic acid, glutamic acid and alanine as cell-wall amino acids; whole-cell hydrolysates contained rhamnose, madurose, glucose, galactose and 3-O-methylmannose as whole-cell sugars.

Ascherxanthone B from Aschersonia luteola, a new antifungal compound active against rice blast pathogen Magnaporthe grisea.

Aims: Fungicide resistance now exists in the rice blast fungus, Magnaporthe grisea, necessitating the need for new active agents. Fungi isolated from habitats in Thailand were screened with reference to this problem.

Methods And Results: A new, reliable in vitro screening system based on a microdilution plate format was set up using a virulent strain of M.

Planotetraspora thailandica sp. nov., isolated from soil in Thailand.

A Gram-positive-staining, filamentous bacterial strain that developed cylindrical sporangia containing four oval- to rod-shaped spores at the ends of short sporangiophores on branched aerial mycelium was isolated from tropical rainforest soil near a hot spring. The cell-wall peptidoglycan contained meso-diaminopimelic acid, glutamic acid and alanine as cell-wall amino acids; the whole-cell hydrolysate contained rhamnose, madurose, glucose, galactose and 3-O-methylmannose as whole-cell sugars. The predominant menaquinone was MK-9(H(4)).

Molecular characterization and expression profiles of cyclin A and cyclin B during ovarian development of the giant tiger shrimp Penaeus monodon.

The meiotic maturation of oocytes is regulated by maturation promoting factor (MPF), a complex of cdc2 (Cdk1) and cyclin B and other Cdk/cyclin complexes. To better understand molecular aspects governing reproductive maturation of the giant tiger shrimp (Penaeus monodon), the full length cDNAs and genomic organization of cyclins A and B (PMCyA and PMCyB) were characterized. A single form of PMCyA contained an open reading frame (ORF) of 1326 bp corresponding to a deduced protein of 441 amino acids.

Up-regulation of microsomal prostaglandin E synthase-1 in COX-1 and COX-2 knock-out mouse fibroblast cell lines.

In this paper we investigated the possible involvement of prostaglandin E synthases (PGESs) in compensatory mechanism. Our findings showed that microsomal (m)PGES-1 expression was significantly up-regulated in COX knock-out (K/O) cells whereas the expression of cytosolic PGES was not changed indicating that the induction of mPGES-1 may, at least in part, contribute to the substantial increase of PGE(2) production in COX K/O cell lines. The selective up-regulation of mPGES-1 in COX-2 K/O cells suggests that mPGES-1 may be metabolically coupled with COX-1 for PGE(2) formation.

ReproArray(GTS): a cDNA microarray for identification of reproduction-related genes in the giant tiger shrimp Penaeus monodon and characterization of a novel nuclear autoantigenic sperm protein (NASP) gene.

Expressed sequence tags (ESTs) were established from various tissues of the giant tiger shrimp (Penaeus monodon). To simultaneously examine expression patterns of a large number of transcripts in ovaries and testes of P. monodon, a cDNA microarray (ReproArray(GTS)) containing 4992 features amplified from cDNAs of ovary (1920) and testis (3072) EST libraries was constructed and subjected to high-throughput gene expression analysis in four different stages of ovarian development (previtellogenesis, vitellogenesis, early cortical rod and late cortical rod stages).

Hydronaphthalenones and a dihydroramulosin from the endophytic fungus PSU-N24.

Three new hydronaphthalenone derivatives (1-3) and one new dihydroramulosin derivative (4), were isolated from the endophytic fungus PSU-N24 together with eight known compounds. Their structures were elucidated by spectroscopic methods. Griseofulvin (9) displayed strong antifungal activity against Microsporum gypseum SH-MU-4 with a minimum inhibitory concentration (MIC) value of 2 microg/ml while all metabolites exhibited very weak antibacterial activity (MIC value>or=128 microg/ml) against Staphylococcus aureus, both standard and methicillin-resistant strains.

Development of antibody array for simultaneous detection of foodborne pathogens.

Pathogenic bacterial contaminations present serious problems for food industry and public health. Rapid, accurate and affordable assays are needed. In this study, antibody arrays to simultaneously detect two foodborne pathogenic bacteria (Escherichia coli O157:H7 and Salmonella spp.

Metabolites from the endophytic fungus Phomopsis sp. PSU-D15.

From the endophytic fungus Phomopsis sp. PSU-D15, three metabolites named as phomoenamide (1), phomonitroester (2) and deacetylphomoxanthone B (3), were isolated together with three known compounds, dicerandrol A (4), (1S,2S,4S)-p-menthane-1,2,4-triol (5) and uridine. Their structures were elucidated by spectroscopic methods.

Biological activities of extracts from endophytic fungi isolated from Garcinia plants.

Sixty-five crude extracts from 51 selected endophytic fungi isolated from Garcinia species were tested for various bioactivities. Eighty per cent of the fungal extracts from fermentation broths and mycelia displayed bioactivities: antimycobacterial (76.9%), antimalarial (14.

A sensitive direct ELISA for detection of prostaglandin E2.

In order to improve the indirect ELISA for detection of PGE(2), a modified direct ELISA technique was developed to measure PGE(2) in cell culture supernatants. An evaluation of three types of coating buffer showed that PGE(2) was adsorbed efficiently to the solid phase using the gelatin phosphate buffer. The sensitivity of the assay was increased by employing polyclonal rabbit anti-PGE(2) antibody dilution of 1/100 and 1% skimmed milk as a blocking solution, with the detection limit of 7.

In search of cyclooxygenase inhibitors, anti-Mycobacterium tuberculosis and anti-malarial drugs from Thai flora and microbes.

Malaria continues to be a major infectious disease of the developing world and the problem is compounded not only by the emergence of drug resistant strains but also from a lack of a vaccine. The situation for tuberculosis (TB) infection is equally problematic. Once considered a "treatable" disease for which eradication was predicted, TB has re-emerged as highly lethal, multi-drug resistant strains after the outbreak of AIDS.

Sulforhodamine B colorimetric assay for cytotoxicity screening.

The sulforhodamine B (SRB) assay is used for cell density determination, based on the measurement of cellular protein content. The method described here has been optimized for the toxicity screening of compounds to adherent cells in a 96-well format. After an incubation period, cell monolayers are fixed with 10% (wt/vol) trichloroacetic acid and stained for 30 min, after which the excess dye is removed by washing repeatedly with 1% (vol/vol) acetic acid.

New racemosol derivatives as potent cyclooxygenase (COX) inhibitors.

Racemosol (1) and 10-O-demethylracemosol (2), natural products from Bauhinia malabarica Roxb., exhibit potent in vitro anti-inflammatory activities against cyclooxygenase-1 and -2 (COX-1 and -2) enzymes. To investigate the structure-activity relationship (SAR) of these molecules, we prepared and fully characterized 17 derivatives by functionalizing one, two, or all three OH group(s) of 2 (Scheme).

Novel biologically active bibenzyls from Bauhinia saccocalyx Pierre.

Four new bibenzyls, bauhinols A-D (1-4), together with the two known bibenzyls 5 and 6, were isolated from the roots of Bauhinia saccocalyx, and their structures were elucidated by analyses of spectroscopic data. Bauhinol A (1) exhibits significant cytotoxicity towards NCI-H187 (small-cell lung cancer), BC (breast cancer), and KB (oral-cavity cancer) cell lines, with IC50 values of 2.7-4.

Synthesis of novel 2-(2'-cyclopentyl)- and 2-(2'-cyclohexyl) substituted 1-naphthol derivatives with anticyclooxygenase activity.

Eight novel 2-(2'-cyclopentyl)- and 2-(2'-cyclohexyl) substituted 1-naphthol derivatives were synthesized in good yield starting from 1-hydroxy-2-naphthoic acid. Two of them, 2-((1-(hydroxymethyl)cyclopentyl)methyl)naphthalene-1-ol (8) and 2-((1-(hydroxymethyl)cyclohexyl)methyl)-naphthalene-1-ol (9) showed anticyclooxygenase activity on COX-2 with IC(50) values of 19.90 microM and 7.

Cloning and expression of xylanase 10 from Cryptovalsa mangrovei (BCC7197) in Pichia pastoris.

Xylanases are one of the industrially valuable enzymes. Using RT-PCR and 5'- and 3'-RACE procedures, we have cloned a full-length xylanase encoding gene from a filamentous fungus, Cryptovalsa mangrovei (BCC7197) from Phuket, Thailand. The results showed that BCC7197 xylanase cDNA has an open reading frame of 978 bp encoding 325 amino acid residues.

Bioactive substances from insect pathogenic fungi.

Insect pathogenic fungi have opened up a relatively untapped area of natural product research which, unfortunately, has not received much attention to date. Found in wild abundance in wet tropical Thailand, the insect fungi are shown to contribute not only as controllers of insect populations but also as rich sources of structurally novel biologically active substances.

Inhibitory effects of 2-substituted-1-naphthol derivatives on cyclooxygenase I and II.

Naphthol derivatives, 2-(3'-hydroxypropyl)-naphthalen-1-ol (2), 2-(3'-hydroxy-2'-methylpropyl)-naphthalen-1-ol (3) and 2-(3'-hydroxy-2',2'-dimethylpropyl)-naphthalen-1-ol (7) were synthesized and already reported by our group. Therefore in this paper we described further synthesis of their ether derivatives, 3-(1-methoxy-naphthalen-2-yl)-propan-1-ol (4), 3-(1-methoxy-naphthalen-2-yl)-2methyl-propan-1-ol (5), 3-(1-methoxy-naphthalen-2-yl)-2,2-dimethyl-propan-1-ol (8), 2-(3-methoxy-propyl)-naphthalen-1-ol (10) and 2-(3-methoxy-2,2-dimethyl-propyl)-naphthalen-1-ol (13). Compounds 4, 5 and 8 were prepared by methylation of compounds 2, 3 and 7, respectively while compounds 10 and 13 were prepared in good yield from naphthols 2 and 7, respectively.

Enniatin production by the entomopathogenic fungus Verticillium hemipterigenum BCC 1449.

Optimal fermentation conditions for enniatin production using the entomopathogenic fungus Verticillium hemipterigenum BCC 1449 have been investigated. Among various liquid media tested, highest efficiency of enniatin production was achieved by fermentation in yeast extract sucrose. Application of this condition to large-scale fermentation resulted in the isolation of three new analogs, O1, O2 and O3, which are closely related isomers that were characterized as an inseparable mixture, along with seven known enniatins.