Sita Preedanon

Phylogenetic diversity of endophyte assemblages associated with the tropical seagrass Enhalus acoroides in Thailand

Seagrasses are flowering plants inhabiting coastal and marine environments, with a worldwide distribution. They serve as feeding, breeding and nursery grounds for economically important marine organisms including endangered species. The tropical seagrass Enhalus acoroides was collected from Had Khanom-Mu Ko Thale Tai National Park, southern Thailand. The objectives of this study were to investigate for the presence of endophyte assemblages in E. acoroides, as well as to describe the diversity of endophytes based on LSU, ITS1, 2, 5.8S rDNA sequence analyses. Forty-two fungal assemblages were isolated and identified through molecular data. This resulted in a diversity of fungal groups of Ascomycota (98%) and Basidiomycota (2%). Three major Ascomycota classes including the Sordariomycetes (36%), Eurotiomycetes (33%) and Dothideomycetes (24%) were determined. The predominant ascomycete orders were the Hypocreales, followed by the Eurotiales and the Capnodiales, respectively. Additionally one taxon belonged to the Russulales, Basidiomycota and was possibly mycorrhiza. This study confirms that E. acoroides harbors a wide diversity of fungal endophytes, and provides a baseline for further studies on fungal-host plant interactions.

Anthraquinone, cyclopentanone, and naphthoquinone derivatives from the sea fan-derived fungi Fusarium spp. PSU-F14 and PSU-F135.

Five new metabolites, fusaranthraquinone (1), fusarnaphthoquinones A-C (2-4), and fusarone (5), were isolated from the sea fan-derived fungi Fusarium spp. PSU-F14 and PSU-F135 along with 18 known compounds. The structures were elucidated on the basis of spectroscopic evidence. Their antibacterial, antifungal, antimycobacterial, antimalarial, and cytotoxic activities were examined.

Sesquiterpene and Xanthone Derivatives from the Sea Fan-Derived Fungus Aspergillus sydowii PSU-F154

Three new sesquiterpenes, named aspergillusenes A and B and (+)-(7S)-7-O-methylsydonic acid, and two new hydrogenated xanthone derivatives, named aspergillusones A and B, were isolated from the sea fan-derived fungus Aspergillus sydowii PSU-F154 together with 10 known compounds. Their structures were identified on the basis of spectroscopic data. The isolated compounds were evaluated for their antioxidant activity.

Epoxydons and a Pyrone from the Marine-Derived Fungus Nigrospora sp. PSU-F5

Nigrospoxydons A-C (1- 3) and nigrosporapyrone (4), four new metabolites, were isolated from the marine-derived fungus Nigrospora sp. PSU-F5 together with nine known compounds. Their structures were elucidated by spectroscopic methods, mainly 1D and 2D NMR spectroscopic techniques. The antibacterial activity against the standard Staphylococcus aureus ATCC 25923 and methicillin-resistant S. aureus was evaluated.

Pyrone derivatives from the marine-derived fungus Nigrospora sp. PSU-F18.

Pyrones, named nigrosporapyrones A-D (1-4), and five known compounds were isolated from the marine-derived fungus Nigrospora PSU-F18. Their structures were elucidated on the basis of spectroscopic evidence. The antibacterial activity against the standard Staphylococcus aureus ATCC 25923 and methicillin-resistant S. aureus was evaluated.

Tetrahydroanthraquinone and xanthone derivatives from the marine-derived fungus Trichoderma aureoviride PSU-F95

Trichodermaquinone (1) and trichodermaxanthone (2) were isolated from the marine-derived fungus Trichoderma aureoviride PSU-F95 together with eleven known compounds. The structures were interpreted by spectroscopic methods. Known coniothranthraquinone 1 and emodin displayed strong antibacterial activity against methicillin-resistant Staphylococcus aureus with the MIC values of 8 and 4 μg/mL, respectively.

Modiolide and pyrone derivatives from the sea fan-derived fungus Curvularia sp. PSU-F22

Investigation of secondary metabolites from the sea fan-derived fungus Curvularia sp. PSU-F22 resulted in isolation of three new metabolites, curvulapyrone (1), curvulalide (2) and curvulalic acid (3) together with six known compounds, modiolides A (4) and B (5), pyrenolide A (6), stagonolide E (7), mycoepoxydiene (8), and deacetylmycoepoxydiene (9). Their antimicrobial activity against Staphylococcus aureus ATCC 25923, methicillin-resistant S. aureus and Microsporum gypseum SH-MU-4 were examined.

Tirisporellaceae, a New Family in the Order Diaporthales (Sordariomycetes, Ascomycota)

Abstract Tirisporella beccariana, a monotypic marine ascomycete, commonly occurs on the lower base of fronds and rhizomes of the brackish water palm, Nypa fruticans. This fungus has globose to subglobose ascomata, immersed to superficial, ostiolate and periphysate, three layered peridium. It has cylindrical bitunicate-like asci, short peduncle, thick-walled, brown ascospores, 4–7 septate, falcate to lunate, verrucose, apical cell appendaged, hyaline basal cell pointed. Taxonomically it was originally assigned to the Dothideomycetes incertae sedis based on the bitunicate-like asci. During on-going investigations of mangrove fungi in Thailand, the fungus was found in intertidal regions in Trang and Trat provinces, Thailand. Maximum parsimony, likelihood and Bayesian analyses using partial SSU and LSU rDNA sequences place T. beccariana in the Diaporthales, Sordariomycetidae, Sordariomycetes; however, the familial level relationship was unidentified. This genus forms a distinct clade with Thailandiomyces bisetulosus isolated from senescent trunks of the palm Licuala longicalycata in Sirindhorn peat swamp forest, with a high statistical support, although they share few morphological features in common.

Flavodonfuran: a new difuranylmethane derivative from the mangrove endophytic fungus Flavodon flavus PSU-MA201

One new difuranylmethane derivative, flavodonfuran (1), together with tremulenolide A (2) was isolated from the mangrove-derived fungus Flavodon flavus PSU-MA201.The difuranylmethane derivative based on 1 is rare in natural products. Their structures were established by spectroscopic evidence. Compound 2 exhibited mild antibacterial and antifungal activities against Staphylococcus aureus ATCC25923 and Cryptococcus neoformans ATCC90113, respectively.

Isolation, fatty acid profiles and cryopreservation of marine thraustochytrids from mangrove habitats in Thailand

Abstract Thraustochytrids, marine protists, have attracted attention as a proven alternative source of polyunsaturated fatty acids (PUFAs). We isolated a high diversity of thraustochytrids from Thailand and tested their potential use in the production of high-value fatty acids. The isolated thraustochytrids can be categorized into seven major groups based on unique morphological features, molecular phylogeny and fatty acid profiles. Two of the seven isolated thraustochytrid groups could potentially be new lineages in the Labyrinthulomycetes. The production of total fatty acid (TFA) from these thraustochytrids ranged from 2.4 to 35.6% (w/w), with biomass varying from 0.3 to 8.9 g l−1. The production of arachidonic acid (C20:4) ranged from 0.3 to 8.2% of TFA, eicosapentaenoic acid (C20:5) from 1.5 to 12.4%, docosapentaenoic acid (C22:5) from 9.7 to 27.3%, and docosahexaenoic acid (C22:6) from 14.4 to 51.7%. In addition, the cryopreservation of selected thraustochytrids at −80°C with 10% glycerol, the combination of 5% trehalose and 10% glycerol, and freezing in vapor-phase liquid nitrogen were found to maintain significant cell viability. The information provided in this study could be applied to cryopreservation and biotechnological applications of the economically valuable marine Labyrinthulomycetes from Thailand.