Fumiquinazolines

Figure 15.2 Solid-phase synthesis of fumiquinazoline alkaloids by Wang and Ganesan [11],...

Wang and Ganesan [92], in the process of synthesizing a series of fumiquinazoline alkaloids, reported the extensive use of long-range H- i N... 

Three new oxepin-containing natural products oxepinamides A-C 166-168 and two new fumiquinazoline metabolites fumiquinazolines H-I 169-170 were isolated from organic extracts of the culture broth and mycelia of Acremonium sp., a fungus obtained from the surface of the Caribbean tunicate Ecteinascidia turbinata Compound 166 exhibited good anti-inflammatory activity in a topical RTX-induced mouse ear edema assay. Compounds 169 and 170 both exhibited weak anti-fungal activity towards Candida albicans in a broth microdilution assay. Total... 

The first total synthesis of (-)-fumiquinazoline A and B was accomplished by B.B. Snider and co-workers using a Buchwald-Hartwig Pd-catalyzed cyclization of an iodoindole carbamate to construct the imidazoindolone moiety. In order to set up the stereochemistry at the benzylic position of the indole fragment, the double bond was oxidized with the saccharine-derived Davis oxaziridine in the presence of methanol to give the major diastereomer in 65% yield. 

Wang, H., Ganesan, A. Total Synthesis of the Fumiquinazoline Alkaloids Solution-Phase Studies. J. Org. Chem. 2000, 65,1022-1030. 

Seven new quinazoline derivatives, fumiquinazolines A-G (120-126), were isolated from the mycelium of another strain of Aspergillus fumigatus obtained from the gastrointestinal tract of the Japanese marine fish Pseudolabrus japonicus. They were obtained as pale-yellow powders (A, B, E, F, G) or as colorless prisms (C, D). Their structure, related to dioxopiperazine, was elucidated by spectroscopic analysis, chemical transformations and, for C and D, X-ray analysis [136,137]. 

Several groups of quinazoline alkaloids involving pyrazino[2,l-fo]quinazoline-3,6-dione substructure are found in fungal metabolites. These include glyantrypine (21) [87], fumiquinazolines A-E, F (22), G (23) [88,89], H and I [90], and fiscalines A-C [91,92]. Novel spiro-type pyrazinoquina-... 

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