Isolation And Structure Analysis Of Two Endophytic Fungi From Maytenus Hookeri Loes.

In recent years, the scientific circles paid more and more attention to the endophytic fungus research. The endophyte is an extremely huge community. The research indicated that the endophytes and the host plants beneficially formed close relationships. As a result, the endophytic fungus possibly produce novel and multiple active substances, such as: antibiotic, anticancer, antioxidant inhibitor substances, pesticides as well as the plant growth regulator metabolites. Endophytes have recently been recognized as a fruitful source of structurally novel and biologically active secondary metabolites.Mayterus hookeri Loes (Yunnan),an evergreen bush belonging to celastraceae, is an effective anticancer medicinal plant. It mainly includes effective anticancer ingredient -maytansine. Endophytes can produce the same or the similar metabolites with the host. Under the mechanism , in order to further isolate the maytansine or anti- cancer active substances, two Endophytes of Mayterus hookeri Loes were investigated.21 compounds were isolated from Alternaria alternata(15 compounds have been identified and the fifteenth is novel structure). From the UV,IR,MS,1H NMR,13CNMR,2D NMR spectroscopic evidences and comparison of the data with those of the literatures,Their structures were identified:(1)alternariol, (2)alternariol monomethyl ether,(3)5'-epialtenuene(4)altenuene,(5)uracil,(6)uridine,(7)adenosine, (8)ACTG toxin-E,(9)tricycloalternarene-3b,(10)alterperylenol,(11)altertoxin I(dihydroalterperylenol),(12)ergosta-4,6,8,22-tetraen-3-one,(13)ergosterol,(14)ergosta-7,24(28)-dien-3-ol,(15) (2E)-6-(3,3a,5,6,7,8,9,9a-octahydro-5-hydroxy-3a- Methyl-8-oxocyclopenta[b]chromen-1-yl)-2-methylhept-2-enal。9 compounds were isolated from the unverificated species.The last four of them are novel. (1)1-Hydroxy-8-methoxyanthraquinone,(2)1,3,6,8-Tetrahydroxyanthraquinone,(3) 1,8-dihydroxyanthraquinone,(4)Cordypyridones C,(5)(E)-2-hexyl-2,3,4,4a,7,8,9,10-Octahydro -9,10,12a-trihydroxy- pyrano[3,2-b]oxecin-6(12aH)-one,(6)microbiolidin B,(7) (E)-2-hexyl- 2,3,4,4a,7,8,9,10- octahydro-9,10-dihydroxy-12a-methoxypyrano[3,2-b]oxecin-6(12aH)-one,(8) (E)-12a-butoxy-2-hexyl-2,3,4,4a,7,8,9,10-octahydro-9,10-dihydroxypyrano[3,2-b]oxecin- 6(12aH)-one。...