Carveol metabolic pathways

Monoterpenols were esterified by lipases from various micro-organisms (especially Aspergillus spp.),931 and ( )-carvyl acetates were hydrolysed by other species to give chiral carveols together with (unreacted) acetates of the enantiomer.932 The metabolic pathways for the conversions of (—)-carvone into (—)-... 

FIGURE 19.87 Metabolic pathways of t) trans- (81a) and (+) cw-carveol (81b) by Streptomyces bottro-pensis SY-2-1. (Modi ed from Noma, Y. and Nishimura, H., Agric. Biol. Chem., 51, 1845, 1987 Nishimura, H. and Noma, Y, Biotechnology for Improved Foods and Flavors, G.R. Takeoka, et al., ACS Symp. Ser. 637, pp.173-187. American Chemical Society, Washington, DC, 1996.)... 

FIGURE 14.83 The Metabolic pathways of ci -carveol (81b ) by Pseudomonas ovalis, strain 6-1 (Modified from Noma, Y, 1977. Nippon Nogeikagaku Kaishi, 51 463-470) and Streptomyces bottropensis SY-2-1 and other microorganisms (Modified from Noma, Y. et al., 1982. Agric. Biol. Chem., 46 2871-2872 Nishimura, H. et al, 1983a. Proc. 27th TEAC, pp. 107-109). 

Streptomyces bottropensis SY-2-1 has also different metabolic pathways for (+)-tra 5-carveol (81a) and (-I-) -di-carveol (81b) (Noma and Iwami, 1994). Namely, Streptomyces bottropensis SY-2-1 converted (+)-trans-caiveo (81a) to (-i-)-carvone (93), (-f-)-carvone-8,9-epoxide (96), and (-i-)-5a-hydroxycarvone (98a) (Noma and Nishimura, 1982, 1984) (Figure 14.87). On the other hand, Streptomyces bottropensis SY-2-1 converted (+)-c -carveol (81b) to give (-)-isobottrospicatol (92b) and (+)-5-hydroxy-c -carveol (94b) as the main products and (-)-bottrospicatol (92a) as the minor product as shown in Figure 14.88 (Noma et al., 1980, Noma and Nishimura, 1987 Nishimura and Noma, 1996). 

In the metabolism of cw-carveol by microorganisms, there are four pathways (pathways 1-4) as shown in Figure 19.86. At rst, cA-carveol (81) is metabolized to carvone (93) by C2 dehydrogenation (Noma, 1977, 1980) (pathway 1). Second, ciY-carveol (81b) is metabolized via epoxide as intermediate to bottrospicatol (92) by rearrangement at C2 and C8 (Noma et al., 1982 Nishimura et al., 1983a,b Noma and Nishimura, 1987) (pathway 2). Third, cA-carveol (81b) is hydroxylated at C5 position to give S-hydroxy-ds-carveol (94) (Noma and Nishimura, 1984) (pathway 3). Finally, cw-carveol... 

Finally, di-carveol (81b) is metabolized to l-p-menthene-2,9-diol (90) by hydroxylation at C9 position (Dhavalikar and Bhattacharyya, 1966 Dhavalikar et al., 1966) (pathway 4). 

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