Publications by authors named "Wilunda Choowong"

Three previously undescribed compounds including 2',3'-dihydroxy-4,5',4″-trimethoxy--terphenyl (), 5-methoxyhydroperoxyco-chliodinol (), and 5-(3',3'-dimethylallyl)indole-3-oxoacetic acid (), along with fifteen known compounds ( - and ), were isolated from the endophytic fungus, BCC71876. The chemical structures were determined by NMR spectral information as well as the comparison with those closely related compounds reported in the literature. The compounds isolated were evaluated for biological properties including antimalarial, anti-TB, anti-plant pathogenic fungal, antibacterial, and cytotoxicity.

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Article Synopsis
  • Eight new lanostane triterpenoids were discovered in Ganoderma cf. hochiminhense, including ganoboninketals G-K and other compounds.
  • The structures of these compounds were determined using NMR spectroscopy and mass spectrometry techniques.
  • Ganoboninketals G, H, and J showed significant antimalarial activity against a drug-resistant strain of Plasmodium falciparum, with IC values of 17, 16, and 5.1 μM, respectively.
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Three previously undescribed highly modified lanostane triterpenoids, ganopyrone A, ganocolossusin I, and ganodermalactone Y, were isolated from the artificially cultivated fruiting bodies of the basidiomycete Ganoderma colossus TBRC-BCC 17711. Ganopyrone A possesses an unprecedented polycyclic carbon skeleton with an α-pyrone ring and C-18/C-23 bond. It showed antimalarial activity against Plasmodium falciparum K1 (multidrug-resistant strain) with an IC value of 7.

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Five undescribed polyketide metabolites, oudemansins E (1), M (2), P (3), and Q (4), and 9-methoxystrobilurin I (5), were isolated from cultures of basidiomycete TBRC-BCC 19434. A γ-lactone derivative (6) of noroudemansin A (8), which was previously reported as a semisynthetic compound, was also isolated. The absolute configuration of the isoprene-derived moiety of the known cometabolite 9-methoxystrobilurin E (9) was determined to be 2',6' by comparison of the experimental and calculated ECD data, which was correlated to the new derivative 1.

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Seven undescribed compounds, including four naphthoquinone terpenoids (aculeolatins A - D), one rare 2-nitropyrrole terpenoid (nitropyrrolin F), and two hydroxamate siderophores (aculeolamides A and B) and one further undescribed compound (2,5,7-trihydroxy-3,6-dimethylnaphthalene-1,4-dione), together with eleven known compounds (arromycin, phenaziterpene A, nitropyrrolin A, heronapyrroles A and B, salaceyin A, 5,7-dihydroxy-2-isopropylchromone, 1-hydroxyphenazine, 1-methoxyphenazine, 1-acetyl-β-carboline, and N-(2-phenylethyl) acetamide), were isolated from the cultures of the endophytic Streptomyces aculeolatus MS1-6. The structures of the isolated compounds were determined using NMR spectroscopy and corroborated using chemical modification. These compounds exhibited a broad spectrum of biological activities, including antimalarial (IC 6.

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A new benzothioate glycoside metabolite, phitsanoside A, together with its new and known derivatives were isolated from Streptomyces sp. TBRC 11511 collected from sediment of a dry evergreen forest located in Phitsanulok Province, Thailand. The structure elucidation of the new compound was interpreted on the basis of spectroscopic data analysis.

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In the quest for medicinally active compounds in mushrooms of the genus Ganoderma, eleven undescribed lanostane triterpenoids, including a novel chlorinated derivative, i.e., (20S,24E)-21-chloro-15β,20,29-trihydroxy-3,7,11-trioxolanosta-8,24-dien-26-oic acid, were isolated from artificially cultivated fruiting bodies of the basidiomycete Ganoderma mbrekobenum.

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Eight new angucyclic quinones, miaosporones A to H (-), along with the previously described metabolites 8-hydroxy-3-methylbenz[]anthraquinone (), tetrangulol (), 5,6-dihydro-1,8-dihydroxy-3-methybenz[]anthracene-7,12-quinone (), and SF2315A (), were isolated from the terrestrial actinomycete TBRC 5172 obtained from sediment collected from the Huai Yang reservoir, Prachuap Khiri Khan Province, Thailand. The relative and absolute configurations of the new compounds were determined from analysis of NMR spectroscopic and X-ray crystallographic data. Miaosporone A exhibited antimalarial activity against K1 and antibacterial activity against with respective IC values of 2.

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Two new hydroquinones bearing a 1,3-enyne moiety, pestalotioquinols G and H, together with four known compounds, including pestalotioquinol A, phomonitroester, ()-4,6,8-trihydroxy-3,4-dihydronaphthalen-1(2)-one, and scylatone were isolated from the marine fungus (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 K1 with an IC value of 19.

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Thirteen tetrahydroxanthone dimers, -ascherxanthone A (), ascherxanthones C-G (-), and confluxanthones A-G (-), were isolated from the entomopathogenic fungus BCC53152. The chemical structures were determined based on analysis of NMR spectroscopic and mass spectrometric data. The absolute configurations of compounds and were confirmed by single-crystal X-ray diffraction experiments, while the configurations of other compounds were assigned based upon evidence from NOESY and NOEDIFF experiments, modified Mosher's method, and ECD spectroscopic data together with biogenetic considerations.

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Ten previously undescribed lanostane-type triterpenoids (1-10), together with 15 known lanostanes, were isolated from artificially cultivated fruiting bodies of the basidiomycete Ganoderma sp. BCC 21329. The structures were elucidated on the basis of NMR spectroscopic and mass spectrometry data and by application of the modified Mosher's method.

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Six new compounds [ascherlactones A (1) and B (2), ascherchromanone A (3), phenethyl 4'-O-methylglucoside (8), 4'-O-methylpleoside (10), and 4'-O-methyltorachrysone 8-O-glucoside (11)] and one naturally new compound [4'-O-methyl-β-d-benzylglucoside (9)] together with fourteen known compounds, including paecilodepsipeptides A (5), B (7), and D (4), conoideocrellide A (6), eugenin (12), 5-hydroxy-2,3-dimethyl-7-methoxychromone (13), (S)-1-phenyl-1,2-ethanediol (14), (2S)-l-3-phenyllactic acid (15), papuline [or (2S)-l-3-phenyllactic acid methyl ester, 16], 2'-epi terpendole A (17), terpendoles C (18) and D (19), cholic acid, and zeorin were isolated from the entomopathogenic fungus Aschersonia confluens BCC53152. Their chemical structures were elucidated on the basis of NMR spectroscopic and mass spectrometric analyses. The absolute configurations were determined by using the evidence from NOESY correlations, chemical means, optical rotation values together with comparison of ECD spectroscopic data with the calculated ECD spectra.

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Fourteen new compounds, oudemansins -, oudemansinols -, favolasins -, favolasinin (), polyketides -, and (,)-2,4-dimethyl-5-phenyl-4-pentene-2,3-diol (), together with nine known compounds were isolated from the basidiomycete fungus sp. BCC 18686. Two new compounds, favolasin E () and 9-oxostrobilurin E (), were isolated from the closely related organism BCC 36684 along with nine β-methoxyacrylate-type derivatives.

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Sixteen previously undescribed lanostane-type triterpenoids (1-16), together with fourteen known compounds, were isolated from cultivated fruiting bodies of the basidiomycete Ganoderma casuarinicola, a recently described species. The structures were elucidated on the basis of NMR spectroscopic and mass spectrometry data. Two of these compounds, 9 and 10, showed antimalarial activity with IC values of 9.

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Two unknown enantiomeric compounds, named ()- and ()-taeniolin, along with six known compounds, were isolated from the marine-associated fungus sp. BCC31839. Chemical structures were determined by NMR spectroscopic techniques, and the absolute configurations were confirmed by Mosher application together with CD spectral analyses.

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Thirty-one highly modified lanostanes (1-31), together with 19 known compounds (32-50), were isolated from fruiting bodies of the wood-rot basidiomycete Tomophagus sp. The structures were elucidated by analyses of HRMS and NMR spectroscopic data. The present work demonstrates the high structural diversity of modified lanostane triterpenoids from Tomophagus.

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Four xanthones (‒) and a known compound, mansonone D (), were isolated from the lignicolous freshwater fungus BCC 28210 (family, Chaetosphaeriaceae). The structures of these compounds were elucidated by extensive spectroscopic analysis. Among the isolated metabolites, compound and the known mansonone D () displayed antimalarial activity against K1 with IC values of 7.

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A new lanostane triterpene (1), together with three known compounds (2-4), were isolated from cultivated fruiting bodies of the basidiomycete Ganoderma australe. The structure was elucidated on the basis of NMR spectroscopic and mass spectrometry data. The olefinic geometry of methyl australate (2) was revised from 20(22)Z to 20(22)E.

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An endophytic actinomycete strain BCC72023 was isolated from rice (Oryza sativa L.) and identified as the genus Streptomyces, based on phenotypic, chemotaxonomic and 16S rRNA gene sequence analyses. The strain showed 99.

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Three new angucyclinones, saccharosporones A, B and C, together with (+)-ochromycinone, (+)-rubiginone B2, tetrangulol methyl ether and fujianmycin A, were obtained from fermentation of the terrestrial actinomycete of the genus Saccharopolyspora BCC 21906 isolated from a soil collected in Chanthaburi Province, Thailand. Structures of the new compounds and their relative configurations were assigned by NMR spectral data interpretation. Saccharosporones A and B exhibited antimalarial activity against Plasmodium falciparum K1 with IC50 values of 4.

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Sterostreins A-E (1, 2, 3a/3b, 4, and 5), five novel terpenoids, were isolated from cultures of the mushroom fungus Stereum ostrea BCC 22955. Sterostrein A (1) exhibited antimalarial activity (IC(50) 2.3 μg/mL) and cytotoxicity (IC(50) 5.

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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.

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