Polyatomic alcohols from the marine isolate of the fungus Aspergillus ochraceus

Abstract

Recent research has demonstrated that fungal micromycetes isolated from marine sources are interesting as producers of biologically active compounds [1–3]. We isolated strains of Aspergillus ochraceus from sediments of Okhotsk Sea during work on a systematic search for biologically active compounds in extracts of marine isolates of microbiological fungi. Fungi were cultivated on solid medium for 21 d at room temperature in nine Ehrlenmeyer flasks (0.5 L), each of which contained medium of composition (g) millet, 15; KH2PO4, 0.001; MgSO4·7H2O, 0.001; sodium tartrate, 0.001; FeSO4·7H2O, 0.0001; seawater, 20 mL. Fungal mycelium with medium was extracted with EtOAc. The extract was evaporated in vacuo. The dry solid (3.453 g) was chromatographed over a column of silica gel with elution by EtOAc:EtOH of increasing polarity. Elution by EtOAc:EtOH (95:5) produced compound 1 (443 mg); by EtOAc:EtOH (50:50), compound 2 (435 mg). (OH)H2C–[CH(OH)]2–CH2(OH) (1), (OH)H2C–[CH(OH)]4–CH2(OH) (2). Meso-erythritol (butan-1,2,3,4-tetraol) (1), C4H10O4, mp 120°C, [ ]D 22 0° (c 1, CH3 OH). Mass spectrum (EI, 70 eV, m/z): 122 (1) [M]+, 91 (23), 60 (100). IR spectrum (KBr, , cm–1): 3268, 2970, 1081, 1053. UV spectrum (H2O, max, nm, ): 259 (1.43). PMR spectrum (500 MHz, C5D5N, , ppm, J/Hz): 4.45 (2H, dd, J = 3.5, 10.5, H-1, H-4), 4.32 (2H, dd, J = 5.6, 10.5, H-1, H-4), 4.40 (2H, m, H-2, H-3). 13C NMR spectrum (125.4 MHz, C5D5N, , ppm): 65.0 (C-1, C-4), 74.2 (C-2, C-3). Meso-erythritol was isolated previously from the algae Protococcus vulgaris and Trentepohlia jolithus in addition to lichens and other fungi [4, 5]. The compound was also used as a sweetner, moisture-retention agent, and stabilizer (E968) in the food industry [6, 7]. Dulcitol (hexan-1,2,3,4,5,6-hexaol) (2), C6H10O6, mp 189°C, [ ]D 22 0° (c 1, CH3OH). Mass spectrum (EI, 70 eV, m/z): 182 (4) [M]+, 149 (53), 31 (100). IR spectrum (KBr, , cm–1): 3395, 3287, 2971, 1081, 1019. UV spectrum (H2O, max, nm, ): 245 (0.12), 271 (0.12). PMR spectrum (500 MHz, C5D5N, , ppm, J/Hz): 4.52 (2H, dd, J = 4.2, 10.8, H-1, H-6), 4.35 (2H, dd, J = 5.8, 10.8, H-1, H-6), 4.60 (2H, m, H-2, H-5), 4.81 (2H, d, J = 7.5, H-3, H-4). 13C NMR spectrum (125.4 MHz, C5D5N, , ppm): 65.4 (C-1, C-4), 73.3 (C-2, C-5), 72.1 (C-3, C-4). PMR spectrum (500 MHz, DMSO-d6, , ppm, J/Hz): 3.39 (2H, m, H-1, H-6), 3.60 (2H, m, H-1, H-6), 4.28 (2H, t, J = 5.4, 1-OH, 6-OH), 3.46 (2H, m, H-2, H-5), 4.36 (2H, d, J = 5.4, 2-OH, 5-OH), 3.54 (2H, m, H-3, H-4), 4.10 (2H, d, J = 7.3, 3-OH, 4-OH). 13C NMR spectrum (125.4 MHz, DMSO-d6, , ppm): 63.9 (C-1, C-4), 71.4 (C-2, C-5), 69.8 (C-3, C-4). Like the compound described above, it had a sweet taste and occurred in marine algae, yeast, and lichens [4]. The yields of 1 and 2 relative to the mass of dry primary (total) extract were 12.8 and 12.6%, respectively. Mesoerythritol and dulcitol were isolated from A. ochraceus for the first time. Our research showed that the strain A. ochraceus is a good producer of polyatomic alcohols that are used in the food industry.