Tremorgenic mycotoxins from Penicillium crustosum. Biosynthesis of penitrem A

Biosynthesis of Sespendole

“…This rearrangement was supported by the observation that the two prominent 13 C-13 C couplings of 1 prepared from sodium [1-13 C]-and [2-13 C]acetate were 40.5 Hz between C-3 and C-4, and 36.2 Hz between C-11 and C-12, respectively. Similar rearrangements were reported in studies on the biosynthesis of the indoloditerpene skeleton in penitrem A [4,5] and nodulisporic acid A [6].…”

“…An attempt to incorporate [2-13 C]tryptophan into 1 was unsuccessful; no 13 C enrichment of any carbon in 1 was observed. This result was unexpected in view of the reported incorporation of tryptophan into the indoloditerpene penitrem A [4,5]. Next, the incorporation of […”

“…5. For most indoloditerpenes, such as penitrem A [4,5], 3-hydroxy-3-methylbutenyl paspalinine [8] and paxilline [8], tryptophan is used as a precursor for the indole moiety, while indole-3-glycerol phosphate, a precursor of tryptophan biosynthesis, is directly incorporated into nodulisporic acid A [6]. In studies of sespendole, anthranilic acid was found to be incorporated into the molecule but tryptophan was not.…”

A synthetic approach to terpendoles: decahydrobenzo[f]chromenes by an intermolecular Diels-Alder route

“…3 These natural products share a common core structure comprised of a cyclic diterpene skeleton derived from geranylgeranyl diphosphate (GGPP) and an indole moiety from tryptophan. [4][5][6][7][8] On the basis of carbon skeleton, it is proposed that these metabolites are biosynthesized by epoxidation of 3-geranyl geranyl indole and subsequent cationic cyclisation similar to the biosynthesis of terpenes and steroids. 4,5 The isolation and structure elucidation of several of these metabolites are well documented.…”

“…[4][5][6][7][8] On the basis of carbon skeleton, it is proposed that these metabolites are biosynthesized by epoxidation of 3-geranyl geranyl indole and subsequent cationic cyclisation similar to the biosynthesis of terpenes and steroids. 4,5 The isolation and structure elucidation of several of these metabolites are well documented. 9 Increasing importance of this class of compounds is evident from the potent inhibitory activity of terpendole C with an IC50 value of 2.1 µM followed by that of terpendoles D (IC50 3.2 µM), A (IC50 15.1 µM), and B (IC50 26.8 µM) (Figure 1).…”