Steroids and Polyketides from the Soil Fungus Penicillium janthinellum XL-7
- PDF / 148,245 Bytes
- 3 Pages / 594 x 792 pts Page_size
- 84 Downloads / 183 Views
STEROIDS AND POLYKETIDES FROM THE SOIL FUNGUS Penicillium janthinellum XL-7
Zhi-Hui Meng, Lan-Lan Xu, Hua-Jie Zhu, and Fei Cao*
Fungi belonging to the Penicillium genus have unique metabolic pathways and genetic backgrounds, leading to the production of diverse secondary metabolites with novel structures and unique activities [1]. Penicillium janthinellum, which is one of the largest species of the genus Penicillium, has proved to be a producer of a variety of secondary metabolites such as alkaloids, terpenes, and steroids [2, 3]. As the research object in this paper, the soil-derived fungus was selected for small-scale fermentation and HPLC-MS analysis. In this study, compounds 1–7 were determined on the basis of their 1H NMR, 13C NMR, and ESI-MS spectroscopic data, and by comparison with previously reported data in the literature. These compounds were identified as β-sitosterol (1) [4], ergosta-5,7,22-triene-3β-ol (2) [5], (22E,24R)-24-methylcholesta-7,22-dien-3β,5α,6β-triol (3) [6], 5α,8α-epidioxy-24Rmethylcholesta-6,22-dien-3β-ol (4) [7], alternariol (5) [8], regiolone (6) [9], and 6,8-dihydroxy-3-methylisocoumarin (7) [10]. All of the isolated compounds were tested for their inhibitory activities against several pathogenic bacteria. Fungus Material. The fungal strain Penicillium janthinellum XL-7 was isolated from soil collected from the Xiao River, Hebei Province of China, in October, 2014. The strain was deposited at the Sanbo Yuanzhi Biotechnology Company, Beijing with the GenBank Acc. No. KY979507. Extraction and Isolation. The fermented solid medium (100 flasks) was extracted three times with MeOH, and the solvent was combined and concentrated in vacuo to afford a residue (8.7 g), which was fractionated by silica gel column chromatography (CC) using a stepwise gradient of petroleum ether (PE)–EtOAc to give six fractions (Frs. 1–6). Fraction 3 was isolated by CC on silica gel (PE–EtOAc, 3:1), then subjected to Sephadex LH-20 CC (CH2Cl2–MeOH, 1:1) and purified by HPLC to obtain 1 (15.9 mg), 2 (12.6 mg), 3 (9.5 mg), and 4 (10.7 mg). Fraction 5 was subjected to silica gel CC (CH2Cl2–MeOH, 20:1), then separated by Sephadex LH-20 CC (PE–CH2Cl2–MeOH, 2:1:1) and further purified by HPLC to afford 5 (13.0 mg), 6 (18.3 mg), and 7 (16.6 mg). β-Sitosterol (1). C29H50O, white amorphous powder. ESI-MS m/z 415.40 [M + H]+. Ergosta-5,7,22-trien-3β-ol (2). C28H44O, white amorphous powder. 1H NMR (600 MHz, CDCl3, δ, ppm, J/Hz): 5.57 (1H, d, J = 5.6, H-6), 5.39 (1H, d, J = 5.6, H-7), 5.20 (1H, dd, J = 14.8, 6.9, H-23), 5.15 (1H, dd, J = 14.8, 7.9, H-22), 1.04 (3H, d, J = 6.6, H-21), 0.95 (3H, s, H-19), 0.92 (3H, d, J = 6.6, H-28), 3.64 (1H, m, H-3), 0.84 (3H, d, J = 7.2, H-26), 0.83 (3H, d, J = 7.2, H-27), 0.63 (3H, s, H-18). 13C NMR (150 MHz, CDCl3, δ, ppm): 141.5 (C-8), 139.9 (C-5), 135.7 (C-22), 132.1 (C-23), 119.7 (C-6), 116.4 (C-7), 70.6 (C-3), 55.8 (C-17), 54.6 (C-14), 46.3 (C-9), 42.9 (C-13), 42.9 (C-24), 40.9 (C-4), 40.5 (C-20), 39.2 (C-12), 38.5 (C-1), 37.1 (C-10), 33.2 (C-25), 32.1 (C-2), 28.4 (C-16), 23.1 (C-15
Data Loading...
