Study On The Chemical Constituents Of The Fungus Leccinum Extremiorientale And Marasmiellus Ramealis (Bull.)

The research of L. extremiorientale was not deep enough, which may contain active ingredients such as alkaloids. As tropical unique fungus, the mycelium fermentation products of Marasmiellus ramealis were barely reported, and the active ingredients such as terpenes were not found. Therefore the two fungus were chosen, and this paper conducted deep study of the chemical constisuents of them.Fourteen compounds were isolated from the EtOH fraction of the fruiting bodies of L. extremiorientale by column chromatography, and their structures were identified as 5-oxo-proline methyl ester (1),5-oxo-proline (2), adenosine (3), uridine (4), a-methyl-D-ribofuranose (5), (2R,3R)-2,3,4-trihydroxy butyrate (6) tetrahydro-2,2,5,5-tetramethylfuran (7), D-arabinose acid 1,4-lactone (8),2-acetamido-1,6-anhydro-2-deoxy-β-D-glucopyranose (9),2-acetamido-1,6-anhydro-2-deoxy-B-D-galactopyranose (10), ergosta-7,22-dien-3β,5a,6β-triol(11),4-[formyl-5-(methoxymethyl)-1H-pyrrol-1-yl] acetic acid (12),4-[formyl-5-(methoxymethyl)-1H-pyrrol-1-yl] butanoic acid (13),4-[formyl-5-(hydroxymethyl)-1H-pyrrol-1-yl] butanoic acid (14) by physicochemical, spectral data as well as comparison with those reported in the literatures. Among them, compounds 12 were a new compound.Thirteen compounds were isolated from the secondary metabolites of Marasmiellus ramealis by column chromatography, and their structures were identified by physicochemical and NMR analysis (ID NMR,2D NMR, UV, IR, MS) as stachyline C (1), cytochalasin D (2),3,4-dihydro-8-hydroxy-3-methylisocoumarin-5-carboxylic acid (3), (R)-(-)-5-ethoxycarbonyl mellein (4),2-(4-hydroxyphenyl)-ethyl acetate (5), 4a-methyl-15-oxa androstane-4β-carboxylic acid-7-ene (6),5a,8a-epidioxy-ergosta-6,22-dien-3β-ol (7),4a-methyl-15-oxa androstane-4β-hydroxyl-7-ene (8), cytochalasin C (9), 13,14-epoxycytochalasin D (10),10-desmethyl-(1β,4a)-dimethyl-13-hydroxymethyl-11- eudesmene (11),10-desmethyl-(1β,4a)-dimethyl-11,13-dihydroxyl-eudesm (12), ergosta-7, 22-dien-3β,5a,6β-triol (13). Among them, compound 4 was new isocoumarin, compounds 6 and 8 were new diterpenoid, as well as compounds 11 and 12 were sesquiterpene compounds.The cytotoxic activities of compounds 12-14 from the fruiting bodies of L. extremiorientale and compound 2 from Marasmiellus ramealis were tested by MTT assay, compounds 2 showed weak inhibitory activities against human liver cancer (BEL-7702) and human stomach cancer (SGC-7901) cell lines. The bioassay of inhibitory activity against acetylcholinesterase (AChE) of these isolates (compounds 6,8,11,12) were evaluated and compounds 6 and 12 exhibited definite high inhibitory activity against AchE 40.80% and 41.02%, compounds 11 showed some inhibitory activity against AchE (29.05%), while compound 8 exhibited no activities (<10%).