Thapong Teerawatananond

Cytotoxic Nor-chamigrane and Chamigrane Endoperoxides from a Basidiomycetous Fungus

A new nor-chamigrane endoperoxide, merulin A (1), and two new chamigrane endoperoxides, merulins B and C (2, 3), were isolated from the culture broth extract of an endophytic fungus of Xylocarpus granatum. Their structures were elucidated on the basis of spectroscopic, mainly NMR and MS, data. X-ray crystallographic analysis confirmed the structure of 1. Compounds 1 and 3 displayed significant cytotoxicity against human breast (BT474) and colon (SW620) cancer cell lines.

Limonoids from seeds of Thai Xylocarpus moluccensis.

A new andirobin, thaimoluccensin A (1), and two new phragmalin-type limonoids, thaimoluccensins B (2) and C (3), were isolated from seeds of a Thai mangrove plant, Xylocarpus moluccensis, together with eight known compounds. The structures of these compounds were elucidated on the basis of spectroscopic data. Only 7-deacetylgedunin (7), a gedunin-type limonoid, exhibited significant inhibitory activity against nitric oxide production from activated macrophages with IC(50) value less than 10 μM, suggesting that the compound has anti-inflammatory activity.

Cytotoxic 3,4-seco-cycloartane triterpenes from Gardenia sootepensis.

Five new 3,4-seco-cycloartanes, sootepins A-E (1-5), along with four known triterpenes (6-9), were isolated from the apical buds of Gardenia sootepensis. Their structures were elucidated on the basis of spectroscopic methods (1D and 2D NMR, HRESIMS, and X-ray crystallography), and the compounds were tested for in vitro cytotoxic activity against human breast (BT474), lung (CHAGO), liver (Hep-G2), gastric (KATO-3), and colon (SW-620) cancer cell lines. Generally, the compounds possessing an exomethylene gamma-lactone ring showed broad cytotoxicity for all cell lines tested.

Xylorumphiins A−D, Mexicanolide Limonoids from the Seed Kernels of Xylocarpus rumphii

Four new mexicanolide limonoids, named xylorumphiins A-D (1-4), were isolated from the seed kernels of Xylocarpus rumphii, together with three known limonoids. Their structures and configurations were established on the basis of spectroscopic data.

Rhytidenones A-F, Spirobisnaphthalenes from Rhytidhysteron sp. AS21B, an Endophytic Fungus.

Rhytidenone A (1), a unique spirobisnaphthalene with a 1,7-dioxaspiro[4,4]nonan-2-one motif, and five new spirobisnaphthalenes, rhytidenones B-F (2-6), were isolated from the extract of a cultured fungal endophyte, Rhytidhysteron sp. AS21B. Their structures were elucidated mainly by analysis of NMR spectroscopic data. The structure and configuration of 1 were further confirmed by single-crystal X-ray diffraction analysis. Compounds 3 and 4 exhibited significant inhibitory activity against nitric oxide production from activated macrophages with IC50 values of 0.31 and 3.60 μM, respectively.

Highly oxygenated chromones from mangrove-derived endophytic fungus Rhytidhysteron rufulum.

Five highly oxygenated chromones, rhytidchromones A-E, were isolated from the culture broth of a mangrove-derived endophytic fungus, Rhytidhysteron rufulum, isolated from Thai Bruguiera gymnorrhiza. Their structures were determined by analysis of 1D and 2D NMR spectroscopic data. The structure of rhytidchromone A was further confirmed by single-crystal X-ray diffraction analysis. These compounds were evaluated for cytotoxicity against four cancer cell lines (MCF-7, Hep-G2, Kato-3 and CaSki). All compounds, except for rhytidchromone D, displayed cytotoxicity against Kato-3 cell lines with IC50 values ranging from 16.0 to 23.3μM, while rhytidchromones A and C were active against MCF-7 cells with IC50 values of 19.3 and 17.7μM, respectively.

Weakly Anti-inflammatory Limonoids from the Seeds of Xylocarpus rumphii

Seven new limonoids, namely, xylorumphiins E-J (1-2 and 4-7) and 2-hydroxyxylorumphiin F (3), along with three known derivatives (8-10), were isolated from the seeds of Xylocarpus rumphii. 2-Hydroxyxylorumphiin F (3) and xylorumphiin I (6) displayed moderate inhibitory activity against nitric oxide production from lipopolysaccharide-activated macrophages with IC50 values of 24.5 and 31.3 μM, respectively.

Spirobisnaphthalenes from the Mangrove-Derived Fungus Rhytidhysteron sp. AS21B

Three new spirobisnaphthalenes (1–3) were isolated from the mangrove-derived fungus Rhytidhysteron sp., together with five known derivatives (4–8). The structures of the compounds were established on the basis of extensive spectroscopic data, and the relative configurations of their stereogenic carbons were determined by a single-crystal X-ray crystallographic analysis. Compounds 3–5 displayed cytotoxicity against both cancer cell lines, MCF-7 and CaSki, while 2 was active only on CaSKi cells.

Chamigrane Sesquiterpenes from a Basidiomycetous Endophytic Fungus XG8D Associated with Thai Mangrove Xylocarpus granatum

Six new chamigrane sesquiterpenes, merulinols A‒F (1‒6), and four known metabolites (7‒10) were isolated from the culture of the basidiomycetous fungus XG8D, a mangrove-derived endophyte. Their structures were elucidated mainly by 1D and 2D NMR, while the structures of 1 and 2 were further confirmed by single-crystal X-ray diffraction analysis. The in vitro cytotoxicity of all compounds was evaluated against three human cancer cell lines, MCF-7, Hep-G2, and KATO-3. Compounds 3 and 4 selectively displayed cytotoxicity against KATO-3 cells with IC50 values of 35.0 and 25.3 μM, respectively.

(4S,5S,6S)-4-Hy­droxy-3-meth­oxy-5-methyl-5,6-ep­oxy­cyclo­hex-2-en-1-one

The title compound, C(8)H(10)O(4), was isolated from culture extracts of the endophytic fungus Xylaria sp. (PB-30). The cyclo-hexenone ring exhibits a flattened boat conformation. In the crystal structure, mol-ecules related by translation along the b axis are linked into chains through O-H⋯O hydrogen bonds. Weak non-classical C-H⋯O contacts are also observed in the structure.