Phytotoxic and Cytotoxic Polyketides Produced by Fungal Endophytes Isolated from Psidium guajava

Tendy Oktriawan (Department of Food, Life, and Environmental Sciences, Faculty of Agriculture, Yamagata University, Tsuruoka, Yamagata 997-8555, Japan. Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Bulaksumur, Yogyakar)
Nanang Ariefta (Department of Food, Life, and Environmental Sciences, Faculty of Agriculture, Yamagata University, Tsuruoka, Yamagata 997-8555, Japan)
Tri Joko Raharjo (Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Bulaksumur, Yogyakarta 55281, Indonesia)
Endang Astuti (Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Bulaksumur, Yogyakarta 55281, Indonesia)
Takuya Koseki (Department of Food, Life, and Environmental Sciences, Faculty of Agriculture, Yamagata University, Tsuruoka, Yamagata 997-8555, Japan)
Yoshihito Shiono (Department of Food, Life, and Environmental Sciences, Faculty of Agriculture, Yamagata University, Tsuruoka, Yamagata 997-8555, Japan)

HAYATI Journal of Biosciences
Vol. 30 No. 3 (2023): May 2023

Endophytic fungi reside within their host plants with no obvious symptoms. They have been proven as abundant sources of new bioactive compounds with diverse structures. In our continuous search of the new compound from endophytic fungi, a new compound, 5,7-dihydroxy-3(R)-methylphthalide (1), was isolated from Xylaria brevipes PGR1, and three known compounds, (–)-altenuene (2), alternariol (3), and altertoxin I (4), were isolated from Alternaria alternata D-8. Both endophytic fungi were isolated from the branch of an Indonesian medicinal plant, Psidium guajava. Their structures were elucidated using extensive spectroscopy analyses, including 1D/2D NMR, HRESITOFMS, and data comparisons with the literature. Compounds 1–3 exhibited phytotoxicity at IC50 (µg/ml) values of 4.6, 23.07, and 77.28, respectively. Additionally, 1–4 showed significant cytotoxicity in the brine shrimp lethality test (BSLT), with mortality rates at 75%, 50%, 90%, and 80% at the concentration of 0.19 μg/ml, respectively.