摘要:
A method for preparing at least one hydroxycholesterol chosen from the group consisting of 25-hydroxycholesterol, 17,25-dihydroxycholesterol and 25,26-dihydroxycholesterol by biological hydroxylation of cholesterol, and the aforementioned dihydroxycholesterols. In the above biological hydroxylation, a microorganism is used which has the abovementioned hydroxylation capacity and which belongs to the genus Amycolata and the genus Sphingomonas.
摘要:
A method for preparing at least one hydroxycholesterol chosen from the group consisting of 25-hydroxycholesterol, 17,25-dihydroxycholesterol and 25,26-dihydroxycholesterol by biological hydroxylation of cholesterol, and the aforementioned dihydroxycholesterols. In the above biological hydroxylation, a microorganism is used which has the abovementioned hydroxylation capacity and which belongs to the genus Amycolata and the genus Sphingomonas.
摘要:
This invention provides DNA fragments for efficiently preparing a protein having asymmetric hydrolase activity for 4-substituted 1,4-dihydropyridine derivatives, transformants obtained by using such a DNA fragment, and a process for preparing the aforesaid enzyme. Specifically, an isolated gene derived from the chromosome of Streptomyces viridosporus and encoding a protein having asymmetric hydrolase activity for 4-substituted 1,4-dihydropyridine derivatives, plasmids having the aforesaid gene integrated thereinto, transformants obtained by using such a plasmid, and a process for preparing the aforesaid enzyme by using such a transformant are disclosed. A process for the enzymatic conversion of 4-substituted 1,4-dihydropyridine derivatives by using the aforesaid enzyme is also disclosed.
摘要:
A biological process for producing steroids hydroxylated at the 25-position thereof comprises adding steroids (excluding cholesterol) to the cells or culture liquid of a microorganism of the genus Amycolata or Sphingomonas capable of hydroxylating the steroids at the 25-position thereof to convert a hydrogen atom bonded to a carbon atom at the 25-position of each steroid into hydroxyl group. By this process, steroids(other than cholesterol) can be biologically hydroxylated at the 25-position by using microorganisms other than those of the genus Streptomyces.
摘要:
Disclosed are 1,4-dihydropyridine derivatives represented by the general formula (I) and salts thereof, as well as optical active 1,4-dihydropyridine derivatives represented by the general formula (II) and salts thereof which are obtained from the derivative by biochemical reactions using microorganisms or enzymes and useful as preventive and therapeutic agents for ischemic heart diseases and hypertension. ##STR1## (wherein x and Y are H, NO.sub.2, CN, halogen; R.sup.1 and R.sup.2 are H, CHO, substituted alkylcarbonyl, crotonyl, cinnamoyl, alkoxycarbonyl, aryloxycarbonyl, benzyloxycarbonyl, carboxybenzoyl, or R.sup.1 and R.sup.2 taken together represent phthaloyl; n is an integer of 1 to 3).
摘要:
(4R)-3-(Substituted aminoalkyl)oxycarbonyl-1,4-dihydro-2,6-dimethyl-4-(nitrophenyl)pyridine-5-carboxylic acids can be prepared efficiently, by reacting bis(substituted aminoalkyl) 1,4-dihydro-2,6-dimethyl-4-(nitrophenyl)pyridine-3,5-dicarboxylates with a microorganism capable of asymmetric hydrolysis and belonging to the genus Streptomyces, the genus Paecilomyces, the genus Botryodioplodia, the genus Alternaria or the genus Helminthosporium, or a treated product thereof. The compounds are extremely useful as important intermediates for preparation of pharmaceuticals useful for the prevention and treatment of angina pectoris, hypertension, etc.
摘要:
A boiling type cooling device for cooling power semiconductors includes an evaporator containing an aqueous solution of ethylene glycol as a cooling medium, a condenser; and a vapor and liquid return pipe. According to a first aspect, the lowest portion of the condensor is at a level higher than the top surface of the cooling medium in the evaporator, the bottom surfaces of the condensor being tilted downward toward the top end of the liquid return pipe. According to another aspect, a pump is provided in the liquid return pipe for driving cooling medium to the evaporator. According to still other aspects, the liquid return pipe is covered with a heat insulating material, or a rubber string extends centrally therewithin. A deaeration device for the aqueous solution of ethylene glycol includes two separate deaeration baths and a mixing bath.
摘要:
An element for detecting internal faults in an insulating gas charged electrical apparatus comprises a substrate disposed in the electrical apparatus charged with an insulating gas, a pair of electrodes disposed on the substrate, and a thin metal film covering the pair of electrodes and the exposed surface of the substrate. This film is capable of producing fluorides with low conductivity upon reacting with a decomposed gas produced by internal faults of the electrical apparatus. Since the thin metal film exhibits high response characteristics readily in reaction with even a trace amount of a decomposed gas, it is possible to promptly detect faults occurring in the electrical apparatus, such as a partial discharge or local heating. In addition, a device for detecting internal faults in an insulating gas charge electrical apparatus using the internal fault detection element utilizes an optical signal for transmitting signals. Accordingly, the device is free from electromagnetically induced interference and is capable of remote monitoring because of the low level of loss in signal transmission.
摘要:
A compound represented by the formula ##STR1## wherein R.sub.1 represents a lower alkyl group or a lower haloalkyl group; R.sub.2 represents a lower alkyl group, a lower haloalkyl group, an aralkyl group, or a group of the formula --COOR.sub.4 or --SO.sub.2 R.sub.5 in which R.sub.4 represents an alkyl group or a substituted or unsubstituted aralkyl group and R.sub.5 represents an alkyl group or a substituted or unsubstituted aryl group; and R.sub.3 represents a hydrogen atom or a carboxyl protecting group which can be easily split off. This compound is useful in the production of a 6-(disubstituted amino)carbapenem-series antibiotic.
摘要:
An azetidinone derivative of the formula ##STR1## wherein R.sub.1 represents a formyl group, a carboxyl group, an acetyloxy group or a group of the formula ##STR2## in which R.sub.2 and R.sub.3 each represent a lower alkyl group or together represent a lower alkylene group, and Z represents a hydrogen atom or an amino-protecting group.