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The entomopathogenic fungus Polycephalomyces nipponicus is known to have activity against human pathogenic bacteria and the malaria pathogen; however, information about its genetic variation is limited. In this study, cicada nymphs infected with entomopathogenic fungi were collected from various locations in the northeast of Thailand. Internal transcribed spacer sequencing was used to identify the fungal pathogen P. nipponicus. A total of 36 isolates of P. nipponicus from 6 provinces were investigated for variations in fungal morphology, nucleoside analog content, and genetics. The results showed that colony morphology varied depending on the strain of the tested fungi, without influence from its geographic origin. A similar finding was observed with regard to the production of nucleoside analog content. Interestingly, the important bioactive compound adenosine was detected in the mycelial extract of all 36 isolates. This indicates that P. nipponicus could possibly be used as a source of potential therapeutic bioactive compounds. In addition, random amplified polymorphic DNA analysis, as supported by the Nei Index and Shannon Index values, showed high genetic variation within and between the populations. These findings represent what is, to our knowledge, the first information on the colony morphology, adenosine analog profile, and genetic variation of P. nipponicus.

This study aimed to identify a suitable organic solvent for extracting bioactive compounds from Polycephalomyces nipponicus and to evaluate the antibacterial and anticancer activities of the extracts obtained. Only extracts obtained with ethyl acetate exhibited antibacterial activity, so ethyl acetate was chosen for large-scale extraction. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against Gram-positive and Gram-negative human pathogenic bacteria of the 3 ethyl acetate-derived extracts-ethyl acetate extract from P. nipponicus (PN-ME), ethyl acetate extract after defatting (PN-ME*), and ethyl acetate extract after refluxation (PN-ME')-were determined. PN-ME' exhibited the most potent activity, inhibiting 12 of the 18 test bacteria, especially Bacillus cereus ATCC 11778 and Vibrio cholera (O1) DMST 9700, with low MIC and MBC values. PN-ME* showed greater inhibitory activity than PN-ME. The effects of the extracts on bacterial cell morphology were also determined. After 120 minutes of treatment with PN-ME* or PN-ME', B. cereus ATCC 11778 exhibited an abnormal rod-shaped cell structure, with some cells elongated to multiple times their original size and others appearing collapsed. V cholera (O1) DMST 9700 cells showed shrinkage and the formed subsurface cavities. PN-ME* and PN-ME' also inhibited the growth of MCF-7 breast cancer cells. In conclusion, the fungal isolate P. nipponicus Cod-MK1201 represents a source of antibacterial and anti-breast cancer compounds.

A new preussomerin isomer, 3'-O-demethylpreussomerin I, five known preussomerins E - I, and two known deoxypreussomerins, deoxypreussomerin A and bipendensin (palmarumycin C11), were isolated from a lichenicolous fungus Microsphaeropsis sp. BCC 3050. These structures were elucidated by spectroscopic methods, especially 1D- and 2D-NMR. The preussomerins were evaluated for their antimycobacterial and antiplasmodial activities as well as cytotoxicity against KB, BC-1 and vero cell lines.