Frenolicins H and I from the caterpillar-associated Streptomyces sp. TBRC17107.

Two undescribed frenolicins H and I (1 and 2) along with six previously described frenolicin analogues [frenolicins A (3), B (4), UCF76-B (5), E - G (6 - 8)] and two anthraquinones [3,8-dihydroxy-1-propylanthraquinone-2-carboxylic acid (9) and 3,8-dihydroxy-1-propylanthraquinone (10)] were isolated from a longkong bark eating caterpillar-derived Streptomyces sp. TBRC17107. The chemical structures were determined by NMR spectroscopic information and HRESIMS data. Frenolicins H (1) and I (2) showed weak cytotoxicity against malignant and non-malignant cells. Frenolicins A (3) and B (4) showed antimalarial activity against Plasmodium falciparum (IC50 17.4 and 1.37 µM), antibacterial activity against Bacillus cereus and Staphylococcus aureus (MIC 50.0 and 0.20 µg/mL). Only frenolicin B had anti-plant pathogenic fungal activity against Collectotrichum acutatum and Alternaria brassicicola with MIC values of MIC 1.56 and 6.25 µg/mL, respectively. Frenolicins A and G possessed anti-Mycobacterium tuberculosis with equal MICs of 25.0 µg/mL.

Two new farnesyl hydroquinones from Pestalotiopsis diploclisia (BCC 35283), the fungus associated with algae.

Two new hydroquinones bearing a 1,3-enyne moiety, pestalotioquinols G and H, together with four known compounds, including pestalotioquinol A, phomonitroester, (R)-4,6,8-trihydroxy-3,4-dihydronaphthalen-1(2H)-one, and scylatone were isolated from the marine fungus Pestalotiopsis diploclisia (BCC 35283). The structures of these compounds were elucidated by analysis of 2D-NMR and HR-MS data. The known pestalotioquinol A displayed antimalarial activity against Plasmodium falciparum K1 with an IC50 value of 19.0 µM, while pestalotioquinol G displayed weak cytotoxic activity against Vero cell lines with an IC50 value of 47.9 µM.

Improved reproductive performance achieved in tropical dairy cows by dietary beta-carotene supplementation.

Dairy farming in tropical climates is challenging as heat stress can impair reproduction in cows. Previous studies have demonstrated the beneficial effects of beta-carotene supplementation on bovine reproductive performance. This study was performed in Thailand, where the temperature-humidity index (THI) during the experimental periods was measured to range from 78.4 to 86.1. Lactating Holstein cows classified as repeat breeders (previous artificial insemination [AI] failures) were randomly assigned into two treatments, control treatment (T1; received placebo, n = 200) and test treatment (T2; received 400 mg/h/day of beta-carotene, n = 200). All cows were subjected to a protocol for synchronization of ovulation and timed artificial insemination (TAI). The day of the 1st ovulation synchronized protocol was defined as day 0, and the total experimental period was 160 days. Daily placebo or beta-carotene supplements were given orally on day 0 and each subsequent day of the experiment. Diagnosis of pregnancy was performed using ultrasound on day 30 after insemination. Non-pregnant cows were subjected to further ovulation synchronizations (maximum of four) and TAI over a period of 160 days. Milk samples were collected every ten days throughout the experiment. The samples were analyzed for beta-carotene concentration, superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities. The pregnancies per AI of the cows in T2 were significantly greater than that of T1 from the 2nd to 4th TAI. During the entire experimental period, the pregnancies in T2 were significantly greater than that of T1. Cox's proportional hazards regression model data indicated a 44% greater probability of pregnancy for cows receiving beta-carotene. The concentrations of milk beta-carotene in T2 were significantly greater than T1 from the 2nd to 4th TAI. Significantly greater SOD and GPx activities were observed in T2 than T1, suggesting a reduction of oxidative stress in cows treated with beta-carotene. Dietary supplementation with beta-carotene thus improves the reproductive performance of repeat breeders exposed to heat stress, possibly by reducing oxidative stress.

Limonoids from fruiting bodies of the wood-rot basidiomycete Fulvifomes xylocarpicola associated with the mangrove tree Xylocarpus granatum.

Three previously undescribed limonoids, fulvifomins A-C, together with two known compounds, 6-deoxydetigloyl-swietenine acetate and methyl angolensate, were isolated from fruiting bodies of the wood-rot fungus Fulvifomes xylocarpicola (Hymenochaetaceae), growing on the mangrove tree Xylocarpus granatum (Meliaceae). The structures were elucidated on the basis of NMR spectroscopic and mass spectrometry data, and X-ray crystallographic analysis (for fulvifomin A). A number of similar limonoids have been isolated from higher plants of the family Meliaceae, including X. granatum. The present study represents a unique evidence that the associated basidiomycete also contains these limonoids. Fulvifomin B exhibited moderate antimalarial and antitubercular activites.

Salicylaldehyde and dihydroisobenzofuran derivatives from the marine fungus Zopfiella marina.

Two salicylaldehyde derivatives (1 and 2), a hydroxymethylphenol (3), five dihydroisobenzofuran (4-8) derivatives, and a 5-chloro-3-deoxyisoochracinic acid (9), together with a known 3-deoxyisoochracinic acid (10) were isolated from the marine fungus Zopfiella marina BCC 18240 (or NBRC 30420). The structures of these compounds were elucidated by extensive spectroscopic analysis. Compound 1 showed weak antituberculous activity against Mycobacterium tuberculosis H37Ra, and antibacterial activity against Bacillus cereus with MIC values of 25 and 12.5 µg/mL, respectively.

Differential regulation of the lipoxygenase pathway in shrimp hepatopancreases and ovaries during ovarian development in the black tiger shrimp Penaeus monodon.

Dietary polyunsaturated fatty acids (PUFAs) are critical to the success of ovarian development in marine crustaceans, especially for domesticated species such as the black tiger shrimp Penaeus monodon. These fatty acids are stored in a midgut gland called the hepatopancreas and subsequently serve as an energy source or are incorporated in yolk during ovarian development. PUFAs are known precursors of hydroxy fatty acids, including hydroxyeicosatetraenoic acid and hydroxyeicosapentaenoic acid (HEPE), which are catalyzed by lipoxygenases (LOX). In previous studies, 8-HEPE has been shown to regulate female reproduction and adipogenesis in marine crustaceans. However, whether the biosynthesis of 8-HEPE in these species is the result of LOX activity has yet to be investigated. In this study, 8-HEPE was identified exclusively in P. monodon hepatopancreases using liquid chromatography-mass spectrometry. Treatment with nordihydroguaiaretic acid resulted in the reduction of 8-HEPE, suggesting the enzyme-dependent catalysis of 8-HEPE in hepatopancreases. Additionally, a full-length P. monodon LOX (PmLOX) was amplified from shrimp ovary cDNA. Sequence analysis revealed that the putative PmLOX contains domains and catalytic residues required for LOX catalytic function. Furthermore, PmLOX expression increased steadily as shrimp ovary maturation progressed, while PmLOX expression and the amount of 8-HEPE decreased in shrimp hepatopancreases. These findings not only suggest differential requirements for hydroxy fatty acid biosynthesis in shrimp ovaries and hepatopancreases during the P. monodon ovarian development, but also provide insights into the LOX pathway in marine crustaceans.

Production and secretion of naphthoquinones is mediated by the MFS transporter MFS1 in the entomopathogenic fungus Ophiocordyceps sp. BCC1869.

Naphthoquinones are deep red polyketide pigments produced by the ant-pathogenic fungus Ophiocordyceps sp. BCC1869. In culture, biosynthesis of these naphthoquinones remains at a low level during the first 20 days and reaches its maximum production level at approximately 50 days. The MFS transporter gene MFS1 was previously identified in Ophiocordyceps sp. BCC1869 from a subtractive EST library between the fungus grown under naphthoquinone-inductive and naphthoquinone-repressive conditions. We cloned and sequenced this transporter gene, which has an open reading frame of 1505 bp and three introns (48, 52, and 58 bp). Phylogenetic analysis showed this MFS transporter was tightly clustered with fungal riboflavin transporters. Functional analysis of this gene was performed by overexpression of MFS1 under the control of a strong, constitutive promoter. We successfully transformed the fungus with this overexpression plasmid using PEG-protoplast transformation, which generated nine transformants per µg of plasmid. RT-PCR indicated that the MFS1 expression level in the overexpressing strains increased 3- to 10-fold compared to the wild type. HPLC analysis of crude extracts of mutants and wild type demonstrated that four naphthoquinone derivatives, erythrostominone, epierythrostominol, deoxyerythrostominone, and deoxyerythrostominol, were the major naphthoquinones produced and excreted in staggering quantities (20- to 2300-fold) in 7-day old liquid cultures by the mutant C7, compared to the wild type. High resolution electrospray ionization mass spectrometry verified mass spectra of these purified metabolites. Three other naphthoquinone derivatives, whose structures have not been identified, were also detected in high amount in the mutant liquid cultures.

Two new drimane sesquiterpenes, fudecadiones A and B, from the soil fungus Penicillium sp. BCC 17468.

Two new drimane sesquiterpenoids, fudecadione A and fudecadione B (1, 2), together with the known brefeldin A (3) and fulvic acid (4), were isolated from the soil fungus Penicillium sp. BCC 17468. Chemical structures were determined based on spectroscopic evidence including 1D and 2D NMR and mass spectral data. The proposed relative stereochemistry of fudecadiones A and B was based upon NOESY spectral data and chemical means. Compounds 1 and 4 exhibited anticancer activity against MCF-7, KB, and NCI-H187, with IC (50) values in the range of 5.05-45.43 µg/mL, while compound 2 was inactive against these tumor cells. Brefeldin (3) also displayed antimalarial activity against PLASMODIUM FALCIPARUM (K1, multidrug-resistant strain), with an IC (50) value of 1.12 µg/mL.

Bioactive metabolites from cultures of basidiomycete Favolaschia tonkinensis.

Two strobilurins, 9-methoxystrobilurin B (1) and 9-methoxystrobilurin G (2), two monochlorinated 2,3-dihydro-1-benzoxepin derivatives, 3 and 4a, and butenolide 5, together with four known compounds, strobilurin B, 9-methoxystrobilurin A, and oudemansins A and B, were isolated from culture BCC 18689 of the fungus Favolaschia tonkinensis. 9-Methoxystrobilurins A, B (1), and G (2) and oudemansins A and B exhibited antimalarial, antifungal, and cytotoxic activities, while compounds 3, 4a, and 5 displayed only cytotoxic activity.