Biotransformation of Citronellal by Solanum aviculare Suspension Cultures:  Preparation of p-Menthane-3,8-diols and Determination of Their Absolute Configurations

Abstract

Citronellal was transformed by Solanum aviculare suspension cultures to menthane-3,8-diols. cis-Menthane-3,8-diol dominated over the trans-isomer (39% and 15%, respectively). Absolute configurations of menthane-3,8-diols were assigned by critical analysis of 1H and 19F NMR spectra of prepared esters with 2-methoxy-2-phenyl-3,3,3-trifluoropropanoic acid. Citronellol and isopulegol were other products of the transformation (23% and 17%, respectively). The reaction course was identical for both citronellal enantiomers.

Biotransformations of Terpenes by Fungi from Amazonian Citrus Plants

“…The strains 2D4 and 1D4 gave the best yields of the isopulegol 16 (12 and 13%, resp.). A similar behaviour was reported with Solanum aviculare [17].…”

“…On the other hand, the strain 1D6 produced the mixture of the diastereoisomers (1S,3S,4S)-pmenthane-3,8-diol (13; 25%) and (1S,3R,4S)-p-menthane-3,8-diol (14; 62%) obtained by ring closure and subsequent addition of H 2 O. The yields of compounds 13 and 14 are very remarkable when compared with those obtained with Solanum aviculare [17]. Both compounds 13 and 14 were also obtained with other strains (i.e., 1B18, 1B24, 2B4, 1C3, 1C22, 1C4, 1D4, 2D1, and 2D4) in variable yields (5 -25% and 5 -60%, resp.).…”

“…These compounds derived from the same cyclic zwitterionic intermediate originating from the nucleophilic attack of the C¼C bond on the aldehydic function. The zwitterionic intermediate gave the diols 13 and 14 through H 2 O addition and the isopulegols 15 and 16 through prototropic rearrangement [17]. Finally, all Fusarium strains both reduced and oxidized the aldehydic function to give (S)-citronellol 12 (36 -76%) and (S)-citronellic acid 11 (5 -43%), respectively.…”

“…TLC (petroleum ether (PE)/AcOEt 5 : 2) to obtain (1S,3R,4S)-p-menthane-3,8-diol (14) and (1S,3S,4S)-p-menthane-3,8-diol (13), characterized by NMR spectra and comparison of their GC/MS data with those of the authentic samples prepared according to the method reported in [17] [28]. The minor products were identified only by GC/MS.…”

“…[11], and Pichia sp. [11]) and citronellal (i.e., Saccharomyces cerevisiae [12] [13], Pseudo-monas aeruginosa [14], Rhodotorula minuta [15], Petroselinum crispum [16], and Solanum aviculare [17]), the biotransformations of sabinene have not been studied.…”