CHECKLISTKawinnat Buaruang et al. / MycoKeys 23: 1-91 (2017) 2 Abstract A new revised checklist of lichenized fungi in Thailand is presented, including 1,292 species. Recent work on the taxonomy of these organisms in Thailand resulted in an enormous increase in our knowledge of the lichen biota of the country -the current checklist includes more than twice as many species as the previous catalogue published 15 years ago -and phylogenetic studies resulted in numerous changes in the generic classification of lichenized fungi. Hence, a new checklist is here presented summarizing the current knowledge of lichens in Thailand. Six new records are reported, viz. Acanthothecis salazinica, Bactrospora metabola, Buellia parastata, Diploschistes cinereocaesius, Rolfidium coccocarpioides, and Trapelia placodioides. Five previously recorded species, namely Lecanora carpinea, Platismatia glauca, P. lacunosa, P. tuckermanii and Roccella phycopsis are shown to be based on misidentifications and are excluded from the checklist. Three new combinations of species previously placed in Pertusaria to Lepra are proposed: L. bulolensis

Five new species and one new record of Astrothelium (Trypetheliaceae) are reported from Thailand. Phylogenetic analysis of four DNA loci (ITS, nuLSU, mtSSU rDNA and RPB1) demonstrated the placement of the new species within Astrothelium, as well as their distinction from similar or related taxa. The new species are: A. flavocoronatum, with a yellow pigment surrounding the ostiole, and 3-septate ascospores 22-28 × 8·0-9·5 µm; A. macrostiolatum, with large whitish ostiolar area, a hamathecium inspersed with small oil droplets, and 9-11-septate ascospores 80-100 × 17-19 µm; A. neglectum, with lichexanthone on the thallus and pseudostromata, a non-inspersed hamathecium and 3-5-septate ascospores 21-25 × 7·5-9·5 µm; A. neovariolosum, with inspersed hamathecium and 3-septate ascospores 17-23 × 6-7 µm; and A. siamense, with inspersed hamathecium and 4-7-septate ascospores 30-50 × 10·5-12·0 µm. Astrothelium aenascens is reported from Thailand for the first time.

Our previous study demonstrated that purple rice bran extract (PRBE) could inhibit diethylnitrosamine (DEN)-induced hepatocarcinogenesis. Protocatechuic acid (PCA) is the major phenolic acid contained in the PRBE. Therefore, this study aimed to determine whether PCA is an anticarcinogenic compound in purple rice extract. Rats were intraperitoneally injected with DEN to induce glutathione S-transferase placental form (GST-P)-positive foci. Rats were fed with PRBE at 500 mg kg−1 body weight or PCA at 4 mg kg−1 body weight for 5 and 15 weeks. PCA administration attenuated DEN-induced hepatic GST-P positive foci to a degree similar to PRBE. The molecular mechanisms of PCA in the initiation stage were correlated with reduced activity of cytochrome P450 reductase and induction of glutathione S-transferase. In addition, PCA also downregulated the expression of TNF-α and IL-1β genes in rat liver. These genes are associated with the inhibition of inflammation. In the promotion stage, PCA suppressed cell proliferation correlated with the downregulation of Cyclin D1 expression. Moreover, it also induced apoptosis, indicated by increased expression of P53 and Bad genes, and decreased the expression of the anti-apoptotic Bcl-xl in DEN-initiated rats. These findings suggest that PCA is an active compound in the anticarcinogenic action of purple rice bran.

The diversity of the Trypethelium eluteriae group in Thailand was studied using molecular (ITS and mtSSU rDNA sequences), morphological, and chemical data. Three species were recognized, T. eluteriae, T. platystomum, and T. subeluteriae, with the latter two being new records for Thailand. The separation of the three species, which have sometimes been regarded as synonymous, is supported by molecular and phenotypic characters. The chemical profiles of the three species are distinct, while ascospore size, often used to distinguish species in the group, shows some overlap.

Architrypethelium murisporum Luangsuphabool, Lumbsch & Sangvichien is described for a crustose lichen occurring in dry evergreen forest in Thailand. It is characterised by a green to yellow-green corticated thallus, perithecia fused in black pseudostromata with white rim surrounding the ostiole and small, hyaline and muriform ascospores. Currently, all species in the genus Architrypethelium have transversely septate ascospores, hence the discovery of this new species indicates that ascospore septation is variable within the genus, similar to numerous other groups of lichen-forming ascomycetes. Phylogenetic analyses of two loci (mtSSU and nuLSU) supported the position of the new species within Architrypethelium. This is the first report of the genus in Southeast Asia.

Architrypethelium murisporum Luangsuphabool, Lumbsch & Sangvichien is described for a crustose lichen occurring in dry evergreen forest in Thailand. It is characterised by a green to yellow-green corticated thallus, perithecia fused in black pseudostromata with white rim surrounding the ostiole and small, hyaline and muriform ascospores. Currently, all species in the genus Architrypethelium have transversely septate ascospores, hence the discovery of this new species indicates that ascospore septation is variable within the genus, similar to numerous other groups of lichen-forming ascomycetes. Phylogenetic analyses of two loci (mtSSU and nuLSU) supported the position of the new species within Architrypethelium. This is the first report of the genus in Southeast Asia.

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Five naphthoquinones including 4 compounds with new absolute configurations, (–)-2' S-trypethelone methyl ether (1), (–)-2' S-8-methoxytrypethelone methyl ether (2), (–)-(2' S,3' S)-4'-hydroxytrypethelone (3), and (–)-(2' S,3' R)-4'-hydroxy-8-methoxy trypethelone methyl ether (5), together with a known compound, (–)-2' S-trypethelone (4), were isolated from cultured mycobiont of Marcelaria cumingii. These compounds were structurally elucidated by high-resolution mass spectra, nuclear magnetic resonance, circular dichroism, optical rotation, and single-crystal X-ray analysis. The cytotoxicity against several cancer cell lines of the isolated compounds were tested. (–)-2' S-Trypethelone methyl ether (1) showed selective inhibition of HCT116 and A549 cell lines with half-maximal inhibitory concentration values of 0.32 ± 0.03 and 1.05 ± 0.12 µM, respectively. The binding conformation and molecular interactions including the effect of substituent modification were also revealed.