357341-99-2

Upstream product

• 81201-92-5 [1-¹³C₁]-L-tryptophan 
• 100-51-6 benzyl alcohol 
• 501-53-1 benzyl chloroformate 
• 357341-97-0 [1-13C]-N-benzyloxycarbonyl-L-isoleucine 
• 357341-98-1 [1-13C]-L-tryptophan benzyl ester 

Relevant academic research and scientific papers

Studies on the biosynthesis of paraherquamide. Construction of the amino acid framework

It has been previously established in this laboratory that the β-methyl-β-hydroxyproline moiety of the potent anthelmintic agent paraherquamide A, is biosynthetically derived from L-isoleucine. The downstream events from L-Ile to paraherquamide A have now been investigated. The synthesis of [1-13C]-labeled L-β-methylproline is described by means of a Hoffman-Loeffler-Freytag reaction sequence from [1-13C]-L-Ile. This amino acid is shown to be a direct biosynthetic precursor to paraherquamide A by feeding and incorporation experiments in growing cultures of Penicillium fellutanum. Three tryptophan-containing dipeptides of L-β-methylproline have been constructed: [13C2]-2-(1,1-dimethyl-2-propenyl)-L-tryptophanyl- 3(S)-methyl-L-proline; [13C2]-3(S)-methyl-L-prolyl-2- (1,1-dimethyl-2-propenyl)-L-tryptophan and [13C2]-cyclo-2-(1,1-dimethyl-2-propenyl)-L- tryptophan-3(S)-methyl-L-proline. [α-15N, 1-13C]-2-(1,1-Dimethyl-2-propenyl)-L-tryptophan was also prepared but none of these substances were found to serve as biosynthetic precursors to paraherquamide A.