Sumalee Supothina

Sterostreins F–O, illudalanes and norilludalanes from cultures of the Basidiomycete Stereum ostrea BCC 22955

Sterostreins F-O (1-10), 10 illudalanes and norilludalanes, were isolated from cultures of the Basidiomycete Stereum ostrea BCC 22955. Their structures were elucidated by analyses of the NMR spectroscopic and mass spectrometry data. Sterostreins M (8), N (9), and O (10) are pyridine-containing illudalanes.

Pyridone and tetramic acid alkaloids from the spider pathogenic fungus Torrubiella sp. BCC 2165.

Torrubiellones A-D (1-4), new pyridone and tetramic acid alkaloids, were isolated from the spider pathogenic fungus Torrubiella sp. BCC 2165. Torrubiellone A (1) exhibited antimalarial activity with an IC(50) value of 8.1 μM, while it showed very weak cytotoxic activity.

Bioactive Compounds from the Scale Insect Pathogenic Fungus Conoideocrella tenuis BCC 18627

A new cyclohexadepsipeptide, conoideocrellide A (1), its linear derivatives, conoideocrellides B-D (2-4), three new hopane triterpenoids (5-7), two new bioxanthracenes (9 and 10), and a new isocoumarin glycoside (13) were isolated from the scale insect pathogenic fungus Conoideocrella tenuis BCC 18627. Biological activities of the new compounds were evaluated.

Antitubercular Activity of Mycelium-Associated Ganoderma Lanostanoids

In a continuation of our research into antitubercular lanostane triterpenoids from submerged cultures of Ganoderma species, three strains, Ganoderma orbiforme BCC 22325, Ganoderma sp. BCC 60695, and Ganoderma australe BCC 22314, have been investigated. Fourteen new lanostane triterpenoids, together with 35 known compounds, were isolated. Antitubercular activities of these mycelium-associated Ganoderma lanostanoids against Mycobacterium tuberculosis H37Ra were evaluated. Taken together with the assay data of previously isolated compounds, structure-activity relationships of the antitubercular activity are proposed. Most importantly, 3β- and 15α-acetoxy groups were shown to be critical for antimycobacterial activity. The most potent compound was (24E)-3β,15α-diacetoxylanosta-7,9(11),24-trien-26-oic acid (35).

Aromadendrane and cyclofarnesane sesquiterpenoids from cultures of the basidiomycete Inonotus sp. BCC 23706.

Twelve aromadendrane sesquiterpenoids, inonotins A-L, and a previously unknown cyclofarnesane, i.e., inonofarnesane, together with two known compounds, were isolated from cultures of the wood-rotting basidiomycete Inonotus sp. BCC 23706. Inonotin I is identical to a previously reported compound with an incorrect structure. Structures of the compounds were elucidated by spectroscopic analysis and X-ray crystallography. The absolute configurations of inonotin D and inonofarnesane were determined by application of the modified Moshers method.

Ascochlorin derivatives from the leafhopper pathogenic fungus Microcera sp. BCC 17074

Two new ascochlorin derivatives, nectchlorins A (1) and B (2), together with eight known compounds (3–10), were isolated from cultures of the leafhopper pathogen Microcera sp. BCC 17074. The structures were elucidated on the basis of NMR spectroscopic and mass spectrometry data. The absolute configuration of 2 was determined by application of the modified Mosher’s method. The absolute configuration of LL-Z 1272α epoxide (9), which is a plausible biosynthetic precursor of ascochlorins, was established by chemical correlations. Cytotoxic activities of these ascochlorin derivatives were evaluated.

Alliacane sesquiterpenoids from submerged cultures of the basidiomycete Inonotus sp. BCC 22670

Nine alliacane sesquiterpenoids, inonoalliacanes A-I, were isolated from culture broth of the basidiomycete Inonotus sp. BCC 22670. The structures were elucidated on the basis of NMR spectroscopic and mass spectrometry data. The absolute configuration of inonoalliacane F was determined by application of the modified Moshers method. Inonoalliacane A, the most abundant sesquiterpene constituent, exhibited moderate antibacterial activity against Bacillus cereus, whereas inonoalliacane B showed antiviral activity against herpes simplex virus type 1.

Hirsutane Sesquiterpenes from Cultures of the Basidiomycete Marasmiellus sp. BCC 22389.

Two new hirsutane sesquiterpenes, marasmiellins A (1) and B (2), were isolated from cultures of the basidiomycete Marasmiellus sp. BCC 22389. The structures were elucidated on the basis of NMR spectroscopic and mass spectrometry data. The absolute configuration of marasmiellin B was determined by application of the modified Mosher’s method.Graphical Abstract

Beauvericin production by the Lepidoptera pathogenic fungus Isaria tenuipes: Analysis of natural specimens, synnemata from cultivation, and mycelia from liquid-media fermentation

Beauvericin was analyzed in three forms of the Lepidoptra pathogenic fungus Isaria tenuipes (4 isolates): (a) natural specimen, (b) cultivated synnemata on rice media, and (c) mycelia from fermentation in liquid media. Beauvericin was detected in very low amounts in all tested natural specimens. Synnemata on rice contained much higher concentrations of beauvericin than the corresponding natural materials, although the concentrations were lower than mycelia from liquid fermentation. The results casted a caution that beauvericin concentration should be carefully checked, as a possible toxic constituent, upon mass production of a selected strain of Isaria tenuipes for health food purposes.

Amethysione and amethysamide, new metabolites from Streptosporangium amethystogenes BCC 27081

Amethysione and amethysamide, new metabolites from Streptosporangium amethystogenes BCC 27081