6-O-demethyl-5-deoxybostrycoidin, A 2-aza-anthraquinone produced by the fungus Nectria haematococca

Total synthesis of four naturally occurring 2-azaanthraquinone antibiotics, 6-deoxy-8-methylbostrycoidin, 6-deoxybostrycoidin, 7-O-demethyl-6-deoxybostrycoidin and scorpinone

“…Spectroscopic data ( 1 H NMR, 13 C NMR, IR, MS) were in accordance with those reported in literature. 11 …”

“…7 Recently, two new 2-azaanthraquinones, scorpinone 8 and 6-deoxy-8-methylbostrycoidin 5, were identified in the mycelium of a Bispora-like tropical fungus and in the cultures of the mycobionts of the lichen Haematomma sp., respectively. 8,9 From a yellow strain mutant of Nectria haematococca, grown in a medium enriched with asparagin 6-deoxybostrycoidin 6 10 and 7-O-demethyl-6-deoxybostrycoidin 7 11 were isolated as intermediates in the bostrycoidin biosynthesis.…”

A Survey of Synthetic Routes towards the Pyranonaphthoquinone Antibiotic Pentalongin and Syntheses of the Corresponding Nitrogen Derivatives

“…It was expected that the formed aldehyde would spontaneously ring-close to the lactol 65 which can be converted into the desired pentalongin (1). The synthesis started with the commercially available 2bromonaphthoquinone (60), which upon radical allylation resulted in 2-allyl-3-bromonaphthoquinone (61). A conventional reduction by tin(II) chloride and methylation using dimethyl sulfate resulted in 2-allyl-3-bromo-1,4dimethoxynaphthalene (62).…”

“…58,59 6-Deoxybostrycoidin (102) and its 7-O-demethyl derivative 103 were isolated from Nectria haematococca (the sexual stage of Fusarium moniliforme), which was grown in an asparagine-enriched culture medium. 60,61 The accumula- tion of 2-aza-anthraquinones 100 and 102 can be explained by the fact that the excess of asparagine furnishes ammonia which is detoxified via the proposed reaction sequence in Scheme 19. 60 During the course of a screening program aimed at colored quinoid substances of fungal origin, the reddish-brown tolypocladin (104) was isolated from Tolypocladium inflatum mutants (DSM 915) and showed metal-chelating properties.…”

Pseudonectrins A–D, heptaketides from an endophytic fungus Nectria pseudotrichia

“…[10][11][12] The species of fungal genus Nectria are well-known for the production of highly colored naphthoquinone derivatives structurally related to fusarubin and bostrycoidin. 10,[13][14][15][16][17][18] While Nectria pseudotrichia, usually considered as a plant pathogen, has been reported to produce naphthoquinones, isocoumarins, and terpenoids. [19][20][21] During our continuous search for new cytotoxic metabolites from the plant endophytic fungi, [22][23][24][25][26][27][28][29] a strain of Nectria pseudotrichia, isolated from the twigs of an identied tree on Tiantangzhai Mountain, Anhui, People's Republic of China, was grown in a solid-substrate fermentation culture.…”