Four xanthones were isolated from mycelia of Emericella variecolor, an endophytic fungus isolated from the leaves of Croton oblongifolius. Their structures were elucidated by spectroscopic analysis to be shamixanthone, 14-methoxytajixanthone-25-acetate, tajixanthone methanoate, and tajixanthone hydrate. All compounds were tested for cytotoxic activity against various human tumor cell lines including gastric carcinoma, colon carcinoma, breast carcinoma, human hepatocarcinoma, and lung carcinoma. The antitumor activities of these xanthones were compared with that of doxorubicin hydrochloride, a chemotherapeutic substance. All of them showed moderate activities and were selective against gastric carcinoma, colon carcinoma, and breast carcinoma. Only tajixanthone hydrate exhibited moderate activity against all cancer cell lines. Furthermore, under the test conditions it was found that 14-methoxytajixanthone-25-acetate and tajixanthone hydrate are almost as active as doxorubicin hydrochloride against gastric carcinoma (KATO3) and breast carcinoma (BT474).

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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

Lichen metabolites have multiple functions in nature and these include several biological activities against pathogens and multi-drug resistant bacteria. This study shows the antibacterial properties of 18 Usnea species collected from five provinces in the northern part of Luzon, Philippines. A total of 41 lichen specimens were extracted using acetone to a final concentration of 10 mg/ml. The crude extracts were initially subjected to TLC. Interestingly, 17 different lichen metabolites were identified. The 41 crude lichen extracts were then tested against Staphylococcus aureus and Bacillus subtilis using paper-disk diffusion assay, most of which were found to be more active against the latter test organism. In addition, 28 of the 41 lichen extracts were also tested against Mycobacterium phlei. Interestingly, most of the samples exhibited much greater activities than that of the antibiotics used as indicated by the zones of inhibition. Moreover, 15 crude extracts showing distinct spots in their TLC profiles were tested against Nocardia asteroides using TLCbioautography. Results showed that usnic acid, norstictic acid, and salazinic acid were the bioactive lichen metabolites.

A total of 292 lichen samples, representing over 200 species and at least 65 genera and 26 families, were collected, mainly in Thailand; 170 of the specimens discharged ascospores in the laboratory. Generally, crustose lichens exhibited the highest discharge rates and percentage germination. In contrast, foliose lichen samples, although having a high discharge rate, had a lower percentage germination than crustose species tested. A correlation with season was indicated for a number of species. Continued development of germinated ascospores into recognizable colonies in pure culture was followed for a selection of species. The most successful medium tried was 2 % Malt-Yeast extract agar (MYA), and under static conditions using a liquid culture medium, a sponge proved to be the best of several physical carriers tested; this novel method has considerable potential for experimental work with lichen mycobionts.

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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.