| Owing to the unique ecological environment,mangrove-derived microorganisms may have specific metabolic pathways to produce the novel bioactive compounds.Mangrove-derived fungi have been separated as the independent one from other marine fungal sources in the statistical research of marine natural products.So,Secondary netabolites from inangrove-derived fungi have been the potential resource of the lead compounds and have important research value.Based on the previous studies.the research continued to study the secondary metabolites of.Xylaria sp.HNWSW-2.The secondary metabolites were isolated by various column chromatographic techniques,and the structures of compounds were identified through a combined analysis of physicochemical properties,as well as by spectral data.The acetylcholinesterase inhibitory activity,antioxidant activity,?-Glucosidase inhibitory activity and nematicidal activities against Punagrellus redivivusl of compounds were evaluated in vitro,respectively.Twenty-six compounds were isolated from the secondary metabolites of mangro ve-derived fungus Xylaria sp.HNWSW-2,including two new polyphenols(1?2),an d one new pyrone(3),five pyrones(4?8),eleven isocoumarins(9?19),five isobenz ofuranones(20?24),one polyketide(25),and one cyclodipeptide(26).Their chemic al structures were identified as:2-(1-hydroxybuthl)-4,5-dihydroxyl-isobenzofuran(1),2-propyl-3.4,6-trihydroxyl-isobenzopyran(2),10-methy-11-hydroxy-5-hydroxymethyl-?-pyrone(3),(R)-(-)-4-hydroxymethyl-5-(1-hydroxypropyl)-3-methoxy-a-pyrone(4),6-ac etyl-4-methoxy-3-methyl-a-pyrone(5),6-(4,5-dihydroxyhex-2-en-2-yl)-4-methoxy-3-met hyl-a-pyrone(6),(8R,10R)-(+)-8-hydroxy-10-methy-5-hydroxymethyl-?-pyrone(7),an d(85,10R)-(-)-8-hydroxy-10-methy-5-hydroxymethyl-?-pyrone(8),(S)-(+)-8-O-methylm ellein(9),3-hydroxymethyl-8-O-methylmellein(10),(3S)-(+)-5-hydroxy-8-O-methylme llein(11),8-methoxy-3-methylisocoumarin(12),6,8-dimethoxy-3-methylisocoumarin(13),(3S,4S)-(+)-4-hydroxy-8-O-methylmellein(14),(3S,4R)-(+)-4-hydroxy-8-O-methyl mellein(15),(3S,4S)-(+)-4-hydroxymellein(16),(3S,4R)-(+)-4-hydroxymellein(17),(3 R,4R)-(-)-4-hydroxy-5-methylmellein(18),(3R,4S)-(+)-4-hydroxy-5-methylmellein(19),1,3-dione-7-methoxyisobenzofuran(20),7-methoxyisobenzofuran(21),3-(1-hydroxye thyl)-7-methoxyisobenzofuranone(22,23),3-(1-hydroxyethyl)-7-rnethoxyisobenzofurano ne(24),phomopsiketones A(25),and cyelo(L-Pro-L-Leu)(26),among them,there are six new natural products(10?12 and 20?23).Among them,there were three ne w compounds(1?3)and six new natural products(10?12 and 20?23).In addition,eighteen compounds(4?9,11?20 and 25?26)were tested for activity.In results,compounds 13 and 26 presented acetylcholinesterase inhibitory activity,and the inhibition rates were 35.22%±2.05%and 44.05%±1.90%,respectively,with the concentration of 0.05 mg/mL,and compounds 11 and 25 showed the DPPH free radicals scavenging activity,respectively,with IC50 values of 1.26 mM and 0.36 mM,respectively,and compounds 5?8 and 12?13 exhibited inhibitory activity of ?-glucosidase,while compounds 7 and 8 exhibited strong inhibitory activity of ?-glucosidase.Compounds 7?8 and 12 IC50 values were 0.62 mM?1.42 mM and 1.09 mM,respectively.Compounds 5 and 26 had nematicidal activities against Punagrellus redivivlsl,in vitro,and compounds 9 and 12?13 exhibited strong nematicidal activities with IC50 of 0.92 mM,2.27 mM and 1.28 mM,respectively.The study researched the secondary metabolites of the mangrove-derived fungus Xylaria sp.HNWSW-2.In results,some of the compounds showed various bioactivitics.Among them,the isocoumarins had remarkable bioactivity for Panagrellus redivivusl.in vitro,which provided a new research idea for the study of agricultural nematode inhibitors. |
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