Penicillium limonene

The fungal bioconversion of limonene was further studied [82]. Penicillium sp. cultures were isolated from rotting orange rind that utilised limonene and converted it rapidly to a-terpineol. Bowen [83] isolated two common citrus moulds, Penicillium italicum and P. digitatum, responsible for the postharvest diseases of citrus fruits. Fermentation of P. italicum on limonene yielded cis- and frans-carveol (93) (26%) as main products, together with cis- and from-p-mentha-2,8-dien-l-ol (110) (18%), (+)-carvone (94) (6%), p-mentha-1,8-dien-4-ol (111) (4%), perillyl alcohol (100) (3%), p-menth-8-ene-1,2-diol (98) (3%), Fig. (17). Conversion by P. digitatum yielded the same products in lower yields. The two alcohols />-mentha-2,8-dien-1 -ol (110) and p-mentha-1,8-dien-4-ol (111) were not described in the transformation studies where soil Pseudomonads were used [69]. 

Fig. (17). Biotransformation products of limonene by Penicillium digitatum and P. italicum (after [83])...

In 1985, the same group [24] investigated the biotransformation of (/ )-(+)-limonene by the fungus Penicillium digitatum. A complete transformation of the substrate to a-terpineol by P. digitatum DSM 62840 was obtained with a yield of 46% pure product. 

The bioconversion of (4/ )-(-)-limonene to (4/ )-(-)-a-terpineol by immobilised fungal mycelia of Penicillium digitatum was described more recently [86]. The fungi were immobilised in Calcium alginate beads. These beads remained active for at least 14 days when they were stored at 4°C. a-Terpineol production by the fungus was 12.83 mg/g beads per day, producing a 45.81% bioconversion of substrate. The optimum conversion temperature was 28°C and the optimum pH was 4.5. The highest... 

In a recent extensive overview on the biotransformation of terpenoids by Aspergillus spp., Noma and Asakawa [92] also mentioned a sixth pathway of limonene bioconversion the hydroxylation at the C-4 position to give / -mentha-1,8-dien-4-ol (111), Fig. (20), a compound also identified earlier as one of the bioconversion metabolites of limonene with Penicillium italicum [83]. In this review, the fifth pathway, leading to isopiperitenol (113) which is further oxidised to isopiperitenone (112) and its rearrangement product, piperitenone (114) is also discussed. 

Photoreaction on (-i-) limonene (orange oil) produces mixed isomers, first couple of fractions canbe used to create active CBl agonists see Schenck 1964. cfs-p-Menth-2-ene-l,8,-diol and mixed isomers from a culture of Penicillium italicum andP digitatum (moldy oranges) see Bowen (1975). 

In the early days of organic chemistry, each new compound was given a name that was usually based on its source or use. Examples (Figs. 1.13 and 1.14) include limonene (from lemons), a-pinene (from pine trees), coumarin (from the tonka bean, known to South American natives as cumaru), and penicillin (from the mold that produces it, Penicillium notatum). Even today, this method of naming can be used to give a short, simple name to a molecule with a complex structure. For example, cubane (p. xxvii) was named after its shape. 

FIGURE 19.29 Biotransformation products of limonene (68) by Penicillium digitatum and Penicillium ita-licum. (Modi ed from Bowen, E.R., Proc. Fla. State Hortic. Soc., 88, 304, 1975.)... 

FIGURE 19.35 Biotransformation of (-)-limonene (68 ) by citrus pathogenic fungi, Penicillium digitatum (Pers. Fr.) Sacc. KCPYN. (Modi ed from Noma, Y. and Asakawa, Y Microbial transformation of limonene and related compounds, Proceedings of 51st TEAC, 2007b, pp. 299-301.)... 

FIGURE 19.40 Microbial resolution of racemic limonene (68 and 68 ) and the formation of optically active a-terpineol by Penicillium digitatum. (Modi ed from Kieslich, K. et al., In Topics in flavor research, R.G. Berger, S. Nitz, and P. Schreier, eds., Marzling Hangenham, Eichborn, 1985, pp. 405-427.)... 

Kieslich et al. (1985) found a nearly complete microbial resolution of a racemate in the Wotransfor-mation of ( )-limonene by Penicillium digitatum (DSM 62840). The (/ )-(+)-hmonene (68) is converted to the optically active (+)-a-terpineol, [alo = +99°, while the (5)-(-)-limonene (68 ) is presumably adsorbed onto the mycelium or degraded via unknown pathways (Kieslich et al., 1985) (Figure 14.40). 

Adams A, Demyttenaere JCR, De Kimpe N (2003) Biotransformation of (R)-(+)- and (S)-(—)-limonene to alpha-terpineol by Penicillium digitatum - investigation of the culture conditions. Food Chem 80(4) 525-534... 

Abdolahi A, Hassani A, Ghosta Y et al (2010) Essential oils as control agents of postharvest Altemaria and Penicillium rots on tomato fruits. J Food Safety 30 341-352 Aggarwal KK, Khanuja SPS, Ateeque A et al (2002) Antimicrobial activity profiles of the two enantiomers of limonene and carvone isolated from the oils of Mentha spicata and Anethum sowa. Flavour Fragr J 17 59-63... 

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