ABSTRACT
Objective: To study the secondary metabolites from the fermentation broth of marine-derived fungus Aspergillus sp. SCS-KFD66. Methods: The constituents were isolated and purified by silica gel, Sephadex LH-20 column chromatography and HPLC methods. The structures of the compounds were identified by spectral data analysis. The DPPH radical scavenging, acetylcholinesterase and α-glucosidase inhibitory activities of compounds were evaluated by DPPH method, Ellman colorimetric method and PNPG method, respectively. The inhibitory effect and the minimal inhibitory concentration (MIC) of compounds on Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Listeria monocytogenes were tested using 96-well microtiter plates method. Results: A total of 13 compounds were isolated from the fermentation broth of marine-derived fungus Aspergillus sp. SCS-KFD66 and identified as 3-epi-trans-4-hydroxylinalool 3,6-oxide (1), trans-4-hydroxylinalool 3,6-oxide (2), aloe emodin (3), emodin (4), citreorosein (5), protocatechualdehyde (6), 2,5-dihydroxybenzaldehyde (7), methyl 4-hydroxyphenylacetate (8), 4-hydroxybenzoic acid (9), 4-hydroxyphenylacetic acid (10), 2-(4-hydroxyphenyl) ethanol (11), (E)-p-hydroxycinnamic acid (12) and (E)-ferulic acid (13), respectively. Compounds 1, 6, 7 and 9-13 showed DPPH radical scavenging activities; Compounds 4 and 6 showed acetylcholinesterase inhibitory activity; Compounds 6 and 7 exhibited inhibitory activity against α-glucosidase. Compound 4 has inhibitory activity against S. aureus and B. subtilis with the MIC values of 16 μg/mL and 64 μg/mL, respectively. Compound 6 showed inhibitory activity against E. coli, B. subtilis and L. monocytogenes, with MIC values of 64, 128 and 128 μg/mL, respectively. Conclusion: Twelve known compounds and one new compound were isolated. Compound 1 is a new compound named as aspergfuranol.
ABSTRACT
Chemical constituents were isolated from the fruiting bodies of Ganoderma australe by various column chromatographic techniques and HPLC method, and their chemical structures were identified through the combined analysis of physicochemical properties and spectral data. Meanwhile, their α-glucosidase inhibitory activity and anti-oxidative ability were evaluated. Seven compounds were isolated from G. australe and were identified as 6-methoxyl-cyclo-(Phe-Ile)(1), applanoxidic acid A methyl ester(2), ergosta-7,22 E-dien-3β-ol(3), cinnamic acid(4), 5α,8α-epidioxy-(20S,22E,24R)-ergosta-6,22-diene-3β-ol(5), 1-(3, 4-dihydroxyphenyl) ethanone(6), salicylic acid(7) and benzoic acid(8). Among the compounds, compound 1 was a new cyclic dipeptide. Compound 2 was a new lanosta natural product, and compounds 4, 6, 7 and 8 were obtained from G. australe for the first time. Moreover, compounds 4 and 8 exhibited α-glucosidase inhibitory activity with inhibition rates of 36.8% and 34.7%, and compounds 4, 7 and 8 had a certain activity in DPPH free radical scavenging activity with IC_(50) values of 0.168, 0.458 and 0.170 g·L~(-1), respectively. The DPPH radical scavenging rate of compound 1 was 41.1%.