摘要:
The invention relates to the isolation of an alkanol from an aqueous biotransformation mixture, in that a) a first alkanol phase is obtained by means of distilling out an alkanol-water azeotrope from the aqueous biotransformation mixture and, if the azeotrope is a heteroazeotrope, phase separating the azeotrope and separating out an aqueous phase, b) a second alkanol phase is obtained by (i) liquid/liquid extracting the first alkanol phase using a solvent as an extracting agent, or (ii) azeotropic drying the first alkanol phase in the presence of the solvent as a carrier agent, and c) the second alkanol phase is fractionally distilled, producing a pure alkanol fraction. The biotransformation mixture is obtained, for example, by means of reducing an alkanol in the presence of an alcohol dehydrogenase. The method is adapted to the severe dilution of the products of value in the biotransformation mixture and works without long phase separation times when extracting by means of organic solvents.
摘要:
The present invention relates to enzymic processes for preparing S-butan-2-ol; and to enzymes for carrying out said processes; to nucleic acid sequences coding for said enzymes, to expression cassettes, vectors and recombinant hosts containing said nucleic acid sequences.
摘要:
The present invention relates to enzymic and nonenzymic processes for preparing 3-methylamino-1-(thien-2-yl)propan-1-ol; as well as to enzymes for implementing these processes; and to nucleic acid sequences encoding these enzymes, to expression cassettes containing these nucleic acid sequences, to vectors and to recombinant hosts.
摘要:
A polypeptide with pyruvate decarboxylase activity, derived from the pyruvate decarboxylase from Zymomonas mobilis by substitution of an amino acid in position 553.
摘要:
A process for preparing optically active alkanols of the formula I in which n is an integer from 0 to 5; Cyc is an optionally substituted, mono- or polynuclear, saturated or unsaturated, carbocyclic or heterocyclic ring, and R1 is halogen, SH, OH, NO2, NR2R3 or NR2R3R4+X−, with R2, R3 and R4 independently of one another being hydrogen or a lower alkyl or lower alkoxy radical and X− being a counterion, which process comprises incubating in a medium comprising alkanone of the formula II in which n, Cyc and R1 are as defined above, an enzyme having a polypeptide sequence (i) SEQ ID NO: 1 or (ii) in which, compared to SEQ ID NO:1, up to 25% of the amino acid radicals have been altered by deletion, insertion, substitution or a combination thereof and which retains at least 50% of the enzymic activity of SEQ ID NO:1, with the compound of the formula II being enzymically reduced to give the compound of the formula I, and isolating the product formed.
摘要翻译:一种制备式I的光学活性链烷醇的方法,其中n为0至5的整数; Cyc是任选取代的单或多核饱和或不饱和的碳环或杂环,R1是卤素,SH,OH,NO2,NR2R3或NR2R3R4 + X-,R2,R3和R4彼此独立地是氢 或低级烷基或低级烷氧基,X是抗衡离子,该方法包括在包含式II的烷酮的培养基中孵育,其中n,Cyc和R 1如上定义,具有多肽序列(i)SEQ ID NO: SEQ ID NO:1或(ii)其中与SEQ ID NO:1相比,通过缺失,插入,取代或其组合改变多达25%的氨基酸基团,并且其保留至少50%的 酶活性为SEQ ID NO:1,其中式II化合物被酶还原,得到式I化合物,并分离形成的产物。
摘要:
The present invention relates to a method for preparing optically active (4S)-4-hydroxy-2,6,6-trimethylcyclohex-2-en-1-one derivatives of the formula (I) and a method for preparing (3S,3′S)-astaxanthin of the formula (III) comprising the first-mentioned method.
摘要:
The present invention relates to enzymic and nonenzymic processes for preparing 3-methylamino-1-(thien-2-yl)propan-1-ol; as well as to enzymes for implementing these processes; and to nucleic acid sequences encoding these enzymes, to expression cassettes containing these nucleic acid sequences, to vectors and to recombinant hosts.
摘要:
The invention relates to a method for producing the optically active alkanols of formula (I), wherein n is an integer of from 0 to 5; Cyc represents an optionally substituted, mononuclear or polynuclear, saturated or unsaturated, carbocylic or heterocyclic ring, and R1 represents halogen, SH, OH, NO2, NR2R3 or NR2R3R4+X−, wherein R2, R3 and R4 independently represent H or a lower alkyl or lower alkoxy group and X− represents a counterion. According to the invention, an enzyme (E) selected from the groups of dehydrogenases, aldehyde reductases and carbonyl reductases is incubated in a medium containing the alkanone of formula (II), wherein n, Cyc and R1 are defined as above, in the presence of reduction equivalents. The compound of formula (II) is enzymatically reduced to the compound of formula (I) and the reduction equivalents consumed during reaction are regenerated by reacting a sacrificial alcohol to the corresponding sacrificial ketone using enzyme (E) and at least partially removing the sacrificial ketone from the reaction medium, and then isolating the product (I) so produced.
摘要:
A mechanically controllable valve drive includes a gas exchange valve on which a transmission arrangement acts via a working contour. The transmission arrangement comprises a first wheel element comprising a toothing which is connected to a camshaft, and a second wheel element comprising a toothing which acts on the gas exchange valve. The transmission arrangement is mounted to move in a cylinder head via a bearing, and is operatively connected to the camshaft and to a valve stroke adjusting device comprising an adjusting shaft. The first and second wheel elements are each mounted to rotate on the adjusting shaft and to be in a geared connection with each another via their respective toothing so that a rotation of the adjusting shaft effects a phase shift between the first and second wheel elements and so that a rotary fixing generates an oscillating movement of the first and second wheel elements.