Polyketide and benzopyran compounds of an endophytic fungus isolated from C innamomum mollissimum: biological activity and structure

• Published in: Asian Pacific Journal of Tropical Biomedicine
• Main Authors: Carolina Santiago, Lin Sun, Murray Herbert Gibson Munro, Jacinta Santhanam
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wolters Kluwer Medknow Publications 2014
• Subjects: Endophytic fungi; HPLC bioactivity profiling; Cinnamomum mollissimum; Antimicrobial; Arctic medicine. Tropical medicine; RC955-962; Biology (General); QH301-705.5; Arctic
• Online Access: https://doi.org/10.12980/APJTB.4.2014APJTB-2014-0030; https://doaj.org/article/f25aa20862ea483b85f01f3f0ecc290f

Objective: To study bioactivity and compounds produced by an endophytic Phoma sp. fungus isolated from the medicinal plant Cinnamomum mollissimum. Methods: Compounds produced by the fungus were extracted from fungal broth culture with ethyl acetate. This was followed by bioactivity profiling of the crude extract fractions obtained via high performance liquid chromatography. The fractions were tested for cytotoxicity to P388 murine leukemic cells and antimicrobial activity against bacteria and pathogenic fungi. Compounds purified from active fractions which showed antibacterial, antifungal and cytotoxic activities were identified using capillary nuclear magnetic resonance analysis, mass spectrometry and admission to AntiMarin database. Results: Three known compounds, namely 4-hydroxymellein, 4,8-dihydroxy-6-methoxy-3-methyl-3,4-dihydro-1H-isochromen-1-one and 1-(2,6-dihydroxyphenyl) ethanone, were isolated from the fungus. The polyketide compound 4-hydroxymellein showed high inhibitory activity against P388 murine leukemic cells (94.6%) and the bacteria Bacillus subtilis (97.3%). Meanwhile, 4,8-dihydroxy-6-methoxy-3-methyl-3,4-dihydro-1H-isochromen-1-one, a benzopyran compound, demonstrated moderate inhibitory activity against P388 murine leukemic cells (48.8%) and the fungus Aspergillus niger (56.1%). The second polyketide compound, 1 (2,6-dihydroxyphenyl) ethanone was inactive against the tested targets. Conclusions: These findings demonstrate the potential of endophytes as producers of pharmacologically important compounds, including polyketides which are major secondary metabolites in fungi.