PROCESS FOR MAKING FLAVOR AND FRAGRANT COMPOUNDS
20240191261 ยท 2024-06-13
Inventors
Cpc classification
International classification
Abstract
Described herein are methods of producing hexenols including: a) contacting a hydroperoxide of a polyunsaturated fatty acid with a modified hydroperoxide lyase to form a hexenal; and b) reducing the hexenal to a hexenol in the presence of a hydride donor, a ketoreductase, and a co-factor, where the contacting and reducing steps are carried out at essentially the same time in the substantial absence of baker's yeast.
Claims
1. A composition comprising (Z)-3-hexenol produced by a method of producing an alcohol comprising: a) contacting a 13-hydroperoxide of a polyunsaturated fatty acid selected from the group consisting of linoleic acid and alpha linolenic acid with a 13-hydroperoxide lyase to form a hexenal; and b) reducing the hexenal in the presence of a hydride donor, a ketoreductase, and a co-factor; wherein the contacting and reducing steps are carried out concomitantly; wherein the hydride donor is selected from the group consisting of a secondary alcohol, a primary alcohol, an alkandiol and a hydroxy acid or one of its esters; the cofactor is selected from the group consisting of NADH and NADPH; the hydroperoxide lyase is stable in the presence of the hydride donor, thus allowing for the concomitant hydroperoxide cleavage and hexanal reduction; and the method is performed in the absence of intact cells; wherein the composition comprises (Z)-3-hexenol in an amount of about greater than or equal to 12000 mg/L and is further provided with about less than or equal to about 170 to about 400 mg/L of the total amount of n-hexanal, (Z)-3-hexenal, (E)-2-hexenal, (E)-2-hexenol, and n-hexanol wherein the n-hexanal, (Z)-3-hexenal, (E)-2-hexenal, (E)-2-hexenol and n-hexanol have not been removed after processing.
2. The composition as recited in claim 1, wherein the ratio (Z)-3-hexenol to the total amount of n-hexanal, (Z)-3-hexenal, (E)-2-hexenal, (E)-2-hexenol, and n-hexanol ranges, by weight, from about 30:1 up to at least about 71:1.
3. The composition as recited in claim 1, comprising (Z)-3-hexenol wherein the composition comprises (Z)-3-hexenol in an amount of about greater than or equal to 12000 mg/L and is further provided with about less than or equal to 400 mg/L of the total amount of n-hexanal, (Z)-3-hexenal, (E)-2-hexenal, (E)-2-hexenol, and n-hexanol produced in the reaction wherein the n-hexanal, (Z)-3-hexenal, (E)-2-hexenal, (E)-2-hexenol, and n-hexanol have not been removed after processing.
4. A composition comprising (Z,Z)-3,6-nonadienol produced by a method of producing an alcohol comprising: a) contacting a 9-hydroperoxide of a polyunsaturated fatty acid selected from the group consisting of linoleic acid and alpha linolenic acid with a 9-hydroperoxide lyase to form an aldehyde selected from the group consisting of a nonenal and nonadienal; and b) reducing the aldehyde in the presence of a hydride donor, a ketoreductase, and a co-factor; wherein the contacting and reducing steps are carried out concomitantly; wherein the hydride donor is selected from the group consisting of a secondary alcohol, a primary alcohol, an alkandiol and a hydroxy acid or one of its esters; the cofactor is selected from the group consisting of NADH and NADPH; the hydroperoxide lyase is stable in the presence of the hydride donor, thus allowing for the concomitant hydroperoxide cleavage and aldehyde reduction; and the method is performed in the absence of intact cells; wherein the composition comprises (Z,Z)-3,6-nonadienol in an amount greater than or equal to about 0.74 g/l, and wherein the composition may comprise about less than or equal to about 1 g/l (Z)-3-nonenol.
5. The composition as recited in claim 4, wherein the ratio of (Z,Z)-3,6-nonadienol to (Z)-3-nonenol ranges from about 4.63 up to about 25:1.
6. A product obtained from a method of producing an alcohol comprising: a) contacting a 9- or 13-hydroperoxide of a polyunsaturated fatty acid selected from the group consisting of linoleic acid and alpha linolenic acid with the respective hydroperoxide lyase to form an aldehyde; and b) reducing the aldehyde to form the alcohol in the presence of a hydride donor, a ketoreductase, and a co-factor wherein the contacting and reducing steps are carried out concomitantly; wherein the hydride donor is selected from the group consisting of a secondary alcohol, a primary alcohol, an alkandiol and a hydroxy acid or one of its esters; the cofactor is selected from the group consisting of NADH and NADPH; the hydroperoxide lyase is stable in the presence of the hydride donor, thus allowing for the concomitant hydroperoxide cleavage and aldehyde reduction; and the method is performed in the absence of intact cells.
7. The composition of claim 6, wherein the composition comprises no (Z)-3-nonenol.
8. The composition of claim 6, wherein the composition comprises (Z,Z)-3,6-nonadienol in an amount greater than or equal to about 4 g/l, and wherein the composition may comprise about less than or equal to about 0.16 g/l (Z)-3-nonenol.
Description
DETAILED DESCRIPTION OF THE DRAWINGS
[0007]
[0008]
[0009]
[0010]
DETAILED DESCRIPTION
[0011] In one embodiment, the hydroperoxide of the polyunsaturated fatty acid provided herein is selected from a 9-hydroperoxide of polyunsaturated acid and a 13-hydroperoxide of a polyunsaturated fatty acid.
[0012] In one embodiment, the aldehyde is a C.sub.6 aldehyde.
[0013] In one embodiment the C.sub.6 aldehyde a hexanal, particularly a n-hexanal.
[0014] In one embodiment the C.sub.6 aldehyde is selected from the group consisting of n-hexanal, (E)-2-hexenal, and (Z)-3-hexenal, particularly (Z)-3-hexenal.
[0015] In one embodiment, the aldehyde is selected from the group consisting of nonenal and nonadienal.
[0016] In one embodiment the aldehyde is selected from the group consisting of (Z)-3-nonenal and (Z,Z)-3,6-nonadienal.
[0017] In yet another embodiment, the alcohol is a C.sub.6 alcohol selected from the group consisting n-hexanol, (E)-2-hexenol, and (Z)-3-hexenol, particularly (Z)-3-hexenol.
[0018] In yet another embodiment, the alcohol is a C.sub.9 alcohol.
[0019] In yet another embodiment, the alcohol is a C.sub.9 alcohol selected from the group consisting (Z)-3-nonenol and (Z,Z)-3,6-nonadienol, particularly (Z,Z)-3,6-nonadienol. In one embodiment, the ratio (Z)-3-hexenol to the total amount of n-hexanal, (Z)-3-hexenal, (E)-2-hexenal, (E)-2-hexenol, and n-hexanol ranges, by weight, from about 30:1 up to at least about 71:1, more particularly from about 30:1 to about 71:1. In one embodiment, the ratio of (Z,Z)-3,6-nonadienol to (Z)-3-nonenol ranges from about 4.63 up to about 25:1.
[0020] In one embodiment, the hydride donor is a compound that donates a hydride of a compound selected from the group consisting of a secondary alcohol, a primary alcohol, an alkandiol and a hydroxy acid or one of its esters.
[0021] In one embodiment, the secondary alcohol is selected from the group consisting of isopropanol, isoamyl alcohol, glycerol, isobutanol, butan-2-ol, propylene glycol, fenchol, borneol, menthol, carveol, methyl-p-tolyl-carbinol, 8-cymenol, oct-1-en-3-ol, pentan-2-ol, pentan-3-ol, 4-methyl-2-pentanol, hexan-2-ol, heptan-2-ol, octan-2-ol, nonan-2-ol, decan-2-ol, undecan-2-ol In a particular embodiment the hydride donor is isopropranol.
[0022] In one embodiment, the hydride donor is an alkandiol selected from the group consisting of, butan-1,4-diol, butan-2,3-diol and ethylene glycol.
[0023] In another embodiment, the hydride donor is a hydroxy acid esters selected from the group consisting of particularly calcium lactate, ethyl lactate, propyl lactate and butyl lactate.
[0024] In one embodiment, the hydroperoxide lyase is a modified lyase produced in a modified organism harboring a recombinant expression plasmid with the modified 13-hpl gene (particular E. coli organism, variant GC7) described e.g. in U.S. Pat. No. 8,501,452 (B2) the entirety of which is incorporated herein by reference.
[0025] In one embodiment, the hydroperoxide lyase is a modified lyase generated by a modified organism harboring a recombinant expression plasmid with a modified 9-hydroperoxide lyase, which is used for producing C.sub.9 aldehydes and after their reduction the C.sub.9 alcohols particularly (Z)-3-nonenol (if 9-hydroperoxide of linoleic acid (9-HPOD) is used as the substrate), or (Z,Z)-3,6-nonadienol (if 9-hydroperoxide of alpha-linolenic acid (9-HPOT) is used as the substrate). From the alcohols the corresponding acetate or other esters may be produced. Particularly, the lyase is generated from an organism harboring a 9-hydroperoxide lyase gene such as described in US Patent Application Publication No.: US2002098570 (A1), the entirety of which is incorporated herein by reference.
[0026] The hydroperoxide lyases are preferably stable in presence of the hydride donor. This is surprising as alcohols for example are known in many cases to destabilize enzymes. The inventors have found that said hydroperoxide lyases are stable in the presence of certain hydride donors that allow for the concommitment hydroperoxide cleavage and aldehyde reduction.
[0027] In one embodiment the ketoreductase is selected from the group consisting of the enzyme ADH005 from Codexis (Redwood City, California) and IEPOx58 of Cambrex-IEP (Wiesbaden, Germany).
[0028] In one embodiment, the 9- and 13-hydroperoxide fatty acid is selected from the group consisting of linoleic acid and alpha-linolenic acid.
[0029] In one embodiment, the co-factor is selected from the group consisting of NADH and NADPH.
[0030] In one embodiment the co-factor regenerating enzyme may be selected from the group consisting of glucose dehydrogenase with glucose as the co-substrate, formiate dehydrogenase with formiate as the co-substrate, or phosphite dehydrogenase with phosphite as the co-substrate.
[0031] One embodiment provided herein is a composition comprising (Z)-3-hexenol wherein the composition comprises (Z)-3-hexenol in an amount of about greater than or equal to 12000 mg/L and is further provided with about less than or equal to about 400 mg/L, more particularly less than about 170 mg/L of total amount of n-hexanal, (Z)-3-hexenal, (E)-2-hexenal, (E)-2-hexenol, and n-hexanol wherein the n-hexanal, (Z)-3-hexenal, (E)-2-hexenal, (E)-2-hexenol, and n-hexanol have not been removed after processing. In another embodiments provided the composition comprises (Z)-3-hexenol in an amount of about greater than or equal to 12000 mg/L and is further provided with about less than or equal 170 up to about 400 mg/L of the total amount of n-hexanal, (Z)-3-hexenal, (E)-2-hexenal, (E)-2-hexenol and n-hexanol wherein the n-hexanal, (Z)-3-hexenal, (E)-2-hexenal, (E)-2-hexenol, and n-hexanol have not been removed after processing.
[0032] In one embodiment, the contacting and reducing steps are carried out at a temperature that ranges from about 0? C. to about 30? C., more particularly form about 10? C. to about 30? C. at a time that ranges from about 2 minutes up to about 480 minutes. In one particular embodiment the temperature is about 20? C. for a time of about 430 minutes. In another particular embodiment, the temperature is about room temperature for a time of about 5 hours. Typically the contacting and reducing steps are carried out with mixing.
[0033] The compounds provided herein are oxygen-containing compounds of current use in the flavor and fragrance industry, namely as a result of their fruity and green type organoleptic characters. There are many studies described in the literature related to a variety of synthetic methods for preparing these compounds, which are known to be constituents of several flavors and fragrances of natural origin.
[0034] One benefit of the current process is that it does not require an intact organism.
EXAMPLES
[0035] The following examples are provided for illustrative purposes only.
Example 1
13-HPOT/D Synthesis
[0036] To a 5-necked glass flask equipped with a mechanical stirrer, a thermometer, a dropping funnel, a glass cap and an oxygen inlet, the mixture of 44 g of linseed oil hydrolysate (ca. 65% of oxidizable acids) and 247.5 g of tap water were added under stirring at 240 rpm. The temperature was adjusted to 18? C. with an ice-water bath. The reaction pH was set by adding 13.2 g of an aqueous solution of 30% of NaOH. The overhead gas phase was purged three times with pure oxygen 02. The glass cap was then quickly replaced with a pH electrode. Then 38.5 g of freshly ground soy flour were added via a flask connected with a flexible hose. The stirring speed was increased to 1000-1200 rpm. The pH was kept constant at pH 9.2 to 9.4 by the drop-wise addition of an aqueous solution of 30% of NaOH. The temperature was maintained between 18-22? C. The reaction was left for one hour. The fatty acid hydroperoxide concentration was determined by iodometric titration with a 0.01 N solution of Na.sub.2S.sub.2O.sub.3. The quality of the fatty acid hydroperoxide was controlled by HPLC. Total fatty acid hydroperoxide as determined by titration reached at least 80 g L.sup.?1 of 13-HPOT/D (13-hydroperoxy-trienoic acid/13-hydroperoxy-dienoic acid).
Example 2
Production of the 13-Hydroperoxide Lyase (13-HPL)
[0037] 0.5 mL of an overnight culture of cells of E. coli harboring a recombinant expression plasmid with the modified 13-hpl gene* was added to a flask with 100 mL of LB medium containing 100 mg mL.sup.?1 of ampicillin and 2 mg L.sup.?1 of thiamine. The culture was grown at 37? C. under shaking at 180 rpm till an optical density of OD.sub.600=0.45 was reached. Then 5-amino-levulinic acid was added to a final concentration of 1 mM. The temperature was lowered to 25? C. within 30 minutes. The culture was induced with 0.1 mM of IPTG at an optical density of OD.sub.600=0.6 and left at 25? C. under shaking for 18 hours. Cells of E. coli were then centrifuged and re-suspended in 100 mM phosphate buffer pH 7.6 to give an OD.sub.600 of 10 prior to sonication using the Labsonic P of Sartorius (G?ttingen, Germany). [0038] * variant GC7, described e.g. in U.S. Pat. No. 8,501,452 (B2)
Example 3
Sequential Cleavage of 13-HPOT/D and Reduction of (Z)-3-Hexenal
[0039] Cleavage of crude 13-HPOT/D was carried out with lysed E. coli cells producing the modified 13-HPL variant GC #7. Into a 10-mL-vial were added: 1.8 mL of 13-HPOT/D >80 g L.sup.?1 and 0.2 mL of lysed cells of E. coli (cell suspension equivalent to OD.sub.600=10) containing the 13-HPL. After 5 min 400 ?L of isopropanol, 25 ?L of NADP (50 mM), and 120 ?L of the enzyme ADH005 (775 U mL.sup.?1) of Codexis (Redwood City, California) were added under stirring. Samples of 100 ?L were withdrawn from the reaction after 2 min, 5 min, 10 min, 20 min, 40 min, 60 min, and immediately diluted with 900 ?L of water. Extraction was with 1 volume of ethyl acetate containing 1 g L.sup.?1 of n-octanol as the internal standard for analysis by gas chromatography. A gas chromatograph equipped with a flame ionization detector and a DB-WAX column (L=30 m, ID=0.25 mm, coating=0.25 ?m) was used following the temperature program: 80? C. (2 min), 160? C. (4? C. min.sup.?1), 230? C. (30? C. min.sup.?1), 230? C. (6 min). The helium flux was 1.4 mL min.sup.?1 using a split ratio of 1:50. After 1 hour the reaction broth contained 7.2 g L.sup.?1 of (Z)-3-hexenol, 0.42 g L.sup.?1 of (Z)-3-hexenal, 0.17 g L.sup.?1 of (E)-2-hexenol, and 0.02 g L.sup.?1 of (E)-2-hexenal. The kinetics of the reaction is shown in
Example 4
a) Concomitant Cleavage of 13-HPOT/D and Reduction of (Z)-3-Hexenal
[0040] Into a 10-mL-vial were added: 1800 ?L of 13-HPOT/D of 80 g L.sup.?1, 4 ?L of 1 M MgSO.sub.4, 25 ?L of 50 mm NADP, 400 ?L of isopropanol, 120 ?L of the ketoreductase ADH005 (775 U mL.sup.?1) of Codexis (Redwood City, California), and 250 ?L of an E. coli lysate (cell suspension equivalent to OD.sub.600=10) containing the 13-HPL (variant GC #7). The reaction was stirred at room temperature. Samples of 100 ?L were withdrawn from the reaction at fixed time points during one hour, diluted with 900 ?L of H.sub.2O and extracted with 1 mL of ethyl acetate prior to analysis by gas chromatography as described in the previous example. n-Octanol served as the internal standard. After 1 hour the reaction broth contained 7.5 g L.sup.?1 of (Z)-3-hexenol, 0.04 g L.sup.?1 of (E)-2-hexenol. No aldehydes were detected. The kinetics of the reaction is shown in
b) Concomitant Cleavage of 13-HPOT/D and Reduction of (Z)-3-Hexenal
[0041] Into a 10-mL-glass-vial were added: 0.9 mL of 13-HPOT/D of 80 g L.sup.?1, 10 ?L of NAD stock solution of 5.2 mM, 200 ?L of isopropanol, 23 ?L of the ketoreductase IEPOx58 of Cambrex-IEP (Wiesbaden, Germany) and 200 ?L of the 13-HPL variant GC7 lysate (made of a cell suspension of OD.sub.600=10). The reaction was stirred with a magnetic bar at 400 rpm at 10? C. for up to 5 hours. The reaction was extracted with 3 volumes of MTBE for analysis by GC using n-octanol as the internal standard. After 5 hour the reaction broth contained 12.3 g L.sup.?1 of (Z)-3-hexenol, 0.02 g L.sup.?1 of (Z)-3-hexenal, 0.07 g L.sup.?1 of (E)-2-hexenol, 0.01 g L.sup.?1 of (E)-2-hexenal, 0.3 g L.sup.?1 of 1-hexanol. The kinetics of the reaction is shown in
Example 5
Preparation of (Z)-3-Hexenol
[0042] Into a 1-L-flask were added 692 mL of 13-HPOT/D at >80 g L.sup.?1, 1.5 mL of 1 M of MgSO.sub.4, 155 mL of isopropanol, 20 mL of 25 mM of NADP, 46 mL of the ketoreductase ADH 005 (775 U mL.sup.?1) of Codexis (Redwood City, California) and 97 mL of lysed cells of E. coli containing the modified 13-HPL of the variant GC #7 (cell suspension equivalent to OD.sub.600=7). The reaction was agitated with a magnetic stirrer at 800 rpm at room temperature for 40 min. Aliquots of 200 ?L were withdrawn after 2, 5, 10, 20 and 40 min to monitor the reaction via gas chromatography. The entire reaction was then extracted 3? with MTBE. The organic extract was washed with water, dried over Na.sub.2SO.sub.4 and filtered with a PTFE membrane of 0.45 ?m pore size prior to removal of the organic solvent by evaporation. The residue was then distilled using a standard distillation apparatus at 70-85? C. under vacuum (15 mbar). The purity of the (Z)-3-hexenol isolated was 97.8% with 1,2% of 1-hexanol, and 0.6% of (E)-2-hexenol as the main impurities (
Example 6
Synthesis of 9-HPOT/D
[0043] The 9-hydroperoxide of alpha-linolenic acid was prepared as follows: A multi-necked glass flask equipped with a mechanical stirrer, a thermometer, a dropping funnel, a glass cap and an oxygen inlet and a vacuum outlet was used. 370 g of freshly mashed potatoes (Charlotte or Bintje) were added to the multi-necked-glass flask. Then 30 g of linseed oil hydrolysate together with 250 gram of water containing 250 ?L of Tween 80 (Sigma Aldrich, P4780), and 370 ?L Viscozym L (Novozymes) were rapidly added. The temperature was adjusted to 20? C.-22? C. and the pH was kept at 5.5 to 5.7 by adding 30% of aqueous NaOH. The system was purged four times with oxygen, vigorously stirred at 800 rpm and kept under oxygen for 1 hour. The oxygen consumption was measured with the help of a burette. The fatty acid hydroperoxide concentration was determined by iodometric titration with 0.01 N of Na.sub.2S.sub.2O.sub.3. The total 9-HPOT/D content (9-hydroperoxy-trienoic acid/9-hydroperoxydienoic acid) should be at least 30 g L.sup.?1.
Example 7
Production of Crude 9-Hydroperoxide Lyase (9-HPL)
[0044] 1 mL of an overnight culture of cells of E. coli DH5a harboring a recombinant expression plasmid based on pMAL-c-2X (New England Biolabs, Ipswich, MA) with the codon modified ORF of the 9-hpl (see e.g. U.S. Pat. No. 7,037,693B2) fused in frame to the 3 end of malE was added to a flask with 200 mL of sterile LB medium containing 100 mg mL-1 of ampicillin and 2 mg L.sup.?1 of thiamine. Cells were grown under shaking at 220 rpm at 37? C. till an optical density of OD.sub.600 of 0.5 was reached. Then 200 microL of 1M of 5-amino-levulinic acid were added to give a final concentration of 1 mM. The temperature was lowered to 25? C. and the culture induced with 0.1 mM of IPTG at an OD.sub.600 of 0.6. The culture was then grown at 180 rpm at 25? C. for another 16 h. Cells were centrifuged at 4? C. and at 4000 g for 30 min. The supernatant was discarded and the cell pellet suspended in ice cold 100 mM phosphate buffer pH 7.6 to reach an OD.sub.600 of 45. Lysozyme was added at 2 mg L.sup.?1 and incubated on ice for 30 min prior to cell disruption by sonication using the LabsonicP (Sartorius, Gattingen, Germany).
Example 8
Sequential Cleavage of 9-HPOT/D and Chemical Reduction of the Aldehydes
[0045] 900 microL of 9-HPOT/D at 35 g L.sup.?1 of total peroxides were added to a glass vial. Then 100 microL of the crude 9-HPL were added under magnetic stirring. Samples of 100 microL were removed after 5 min, 10 min, 15 min and 20 min and immediately reduced in 900 microL of aqueous NaBH.sub.4 of 10 g L.sup.?1 under magnetic stirring at room temperature for 10 min. The reduced samples were extracted with 2 mL of MTBE containing 1-octanol as the internal standard and analyzed by GC using a DB-WAX column. After 5 minutes 0.2 g L.sup.?1 of (Z)-3-nonenol and 0.9 g L.sup.?1 of (Z,Z)-3,6-nonadienol were detected (Table 1).
TABLE-US-00001 TABLE 1 Time (Z)-3-nonenol (Z,Z)-3,6-nonadienol Total (min) (g L.sup.?1) (g L.sup.?1) (g L.sup.?1) 5 0.20 0.90 ? 0.01 1.11 ? 0.01 10 0.21 ? 0.01 0.92 ? 0.06 1.14 ? 0.08 15 0.20 ? 0.01 0.86 ? 0.04 1.06 ? 0.05 20 0.18 ? 0.06 0.80 ? 0.02 0.99 0.03
Example 9
Sequential Cleavage of 9-HPOT/D and Biochemical Reduction of the Aldehydes
[0046] 1800 microL of 9-HPOT/D of 35 g L.sup.?1 were added to a glass vial. Then 200 microL of the crude 9-HPL were added under magnetic stirring. The reaction was left under magnetic stirring at 900 rpm at room temperature for 5 min. Two samples of 100 microL each were removed as controls, reduced with NaBH.sub.4 and analyzed as described. To the remainder of the reaction were immediately added: 120 microL of an aqueous 10 mM NADP, 160 microL H.sub.2O, 70 microL of isopropanol, 11 microL of 1M MgSO.sub.4, and 100 microL of the ketoreductase ADH005 (775 U mL.sup.?1) of Codexis (Redwood City, California). The pH was adjusted to pH 7 by adding 12 microL of 20% NaOH under strong magnetic stirring. Samples of 200 microL were removed at different time intervals, extracted with 15 volumes of MTBE and analyzed by GC as described using 1-octanol as the internal standard. The biochemical reduction resulted in 0.13 g L.sup.?1 of (Z)-3-nonenol and 0.59 g L.sup.?1 of (Z,Z)-3,6-nonadienol with no free aldheydes detected after 5 minutes.
Example 10
Concomitant Cleavage of 9-HPOT/D and Reduction of the Aldehydes
[0047] 1620 microL of 9-HPOT/D of 35 g L.sup.?1 were added to a glass vial. Then 120 microL of 10 mM NADP, 160 microL of H.sub.2O, 70 microL of isopropanol, 11 microL of 1M MgSO.sub.4, 100 microL of the ketoreductase ADH005 of (775 U mL.sup.?1) of Codexis (Redwood City, California), 180 microL of crude 9-HPL (OD.sub.600=45) and 12 microL of 20% NaOH were added under stirring at room temperature (final pH=7). Samples of 200 microL were removed at different time intervals, extracted with 15 volumes of MTBE and analyzed by GC as described using 1-octanol as the internal standard. The biochemical reduction resulted in 0.16 g L.sup.?1 of (Z)-3-nonenol and 0.68 g L.sup.?1 of (Z,Z)-3,6-nonadienol with no free aldheydes detected after 5 minutes of reduction time.
Example 11
Concomitant Cleavage of 9-HPOT/D and Reduction of the Aldehydes
[0048] 1620 microL of 9-HPOT/D of 35 g L.sup.?1 were added to a glass vial. Then 40 microL of 10 mM NAD, 160 microL of H.sub.2O, 70 microL of isopropanol, 200 microL of the ketoreductase IEPOx58 of Cambrex-IEP (Wiesbaden, Germany), 180 microL of crude 9-HPL (OD.sub.600=45) and 12 microL of 20% NaOH were added under stirring at room temperature (final pH=7). Samples of 200 microL were removed at different time intervals, extracted with 15 volumes of MTBE and analyzed by GC as described using 1-octanol as the internal standard. The biochemical reduction resulted in 0.16 g L.sup.?1 of (Z)-3-nonenol and 0.74 g L.sup.?1 of (Z,Z)-3,6-nonadienol with no free aldheydes detected after 15 minutes of reduction time.