Secondary metabolites isolated from Penicillium christenseniae SD.84 and their antimicrobial resistance effects

Abstract

A pair of new quinolone alkaloid enantiomers, (Ra)-(-)-viridicatol (1) and (Sa)-(+)-viridicatol (4), along with seven known compounds 2, 3, and 5-9 were isolated from Penicillium christenseniae SD.84. The structure of 1and 4 ware determined by NMR and HRESIMS data. Compound 1 and 4 were determined to be a pair of enantiomers by theoretical calculation through CD and ECD. The MIC values of compound 4 against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus were 12.4 μM and 24.7 μM, compound 1 has no inhibitory activity. Antimicrobial assays of compounds 2, 3 and 5-7 showed moderate activity against methicillin-resistant Staphylococcus aureus and Staphylococcus aureus. This study reveals the significant potential of Penicillium sp. to produce new drug-resistant lead compounds, therefore increasing the speed in the mining for new sources of antimicrobial agents.

Screening extracts of fungal endophytes isolated from Allophylus abyssinicus (Hochst. Radlk.) for control of bean anthracnose

“…In another study, compounds isolated from A. burnettii had antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, Candida albicans and Saccharomyces cerevisiae in the bioassay screening (Gilchrist et al, 2020) indicating that extracts from fungal endophytes in the genus Aspergillus have antimicrobial properties. Antifungal activity of P. christenseniae is in line with the findings of Wang et al (2022) indicated that secondary metabolites isolated from this fungus had antimicrobial activity against S. aureus and methicillinresistant S. aureus.…”

“…contains active natural products and this secondary metabolites are involved in inhibitory activities against microbes (Kozlovskii et al, 2013). Presence of alkaloids in P. christenseniae crude extracts is in line with the findings of Wang et al (2022) whereby, two new quinolone alkaloid enantiomers, (Ra)-(-)-viridicatol (1) and (Sa)-(+)-viridicatol (4) and seven other known compounds were isolated from P. christenseniae SD.84. The presence of steroids in P. christenseniae ethyl acetate crude extract could have contributed to the inhibition of 10.3±0.6 mm, with the difference in inhibition being probably a result of synergy of the chemical constituents present in each extract.…”

“…This result corresponds to Korejo et al (2014) findings where endophytic Penicillium species exhibited significant antifungal activity against Fusarium solani, Fusarium oxysporum and Rhizoctonia solani. Penicillium christenseniae SD.84 isolated from the soil had antimicrobial activity against several bacterial and fungal pathogens in vitro as reported by Wang et al (2022). Both A. hancockii and P. christenseniae have not been previously screened against C. lindemuthianum.…”