摘要:
New compounds, 6"-deoxydibekacin, 4", 6"-dideoxydibekacin, 1-N-(L-4-amino-2-hydroxybutyryl)-6"-deoxydibekacin and 1-N-(L-4-amino-2-hydroxybutyryl)-4",6"-dideoxydibekacin are now produced semi-synthetically from dibekacin, i.e. 3',4'-dideoxykanamycin B. These four new compounds are each useful as an antibacterial agent. Production of 6"-deoxydibekacin or 4",6"-dideoxydibekacin is made by removal of the 6"-hydroxyl group or by removal of the 4"- and 6"-hydroxyl groups from an amino-protected and hydroxyl-protected derivative of dibekacin. Production of 1-N-(L-4-amino-2-hydroxybutyryl)-6"-deoxydibekacin or -4",6"-dideoxydibekacin is made by acylating the 1-amino group of 6"-deoxydibekacin or 4",6"-dideoxydibekacin with the L-4-amino-2-hydroxybutyryl group, or alternatively by removal of the 6"-hydroxyl group or the 4"- and 6"-hydroxyl groups from a known compound, 1-N-(L-4-amino-2-hydroxybutyryl)-dibekacin.
摘要:
Four new antibiotics which are denominated istamycin A, istamycin B, istamycin A.sub.o and istamycin B.sub.o, and which are useful as antibacterial agents, are produced by fermentation of a new microorganism, Streptomyces tenjimariensis.
摘要:
1-N-(L-4-amino-2-hydroxybutyryl) derivatives of kanamycin C, 3'-deoxykanamycin C and 3',4'-dideoxykanamycin C have been prepared which possess high antibacterial activity against a wide variety of drug-resistant bacteria. These new derivatives are prepared by reacting L-4-amino-2-hydroxybutyric acid or a functional equivalent thereof with the 1-amino group of kanamycin C, 3'-deoxykanamycin C or 3',4'-dideoxykanamycin C.
摘要:
Kanamycin C, 3'-deoxykanamycin C and 3'4'-dideoxykanamycin C are obtained by a new process comprising treating the primary 6'-amino group of a tetra-N-protected derivative of kanamycin B, 3'-deoxykanamycin B and 3', 4'-dideoxykanamycin B with a nitrite to convert said amino group into hydroxyl group and then removing the protective groups. 3'-Deoxykanamycin C and 3', 4'-dideoxykanamycin C are new semi-synthetic aminoglycosidic antibiotics.
摘要:
An 1-N-((S)-.alpha.-substituted-.omega.-aminoacyl)-neamine or -ribostamycin of the formula ##STR1## wherein R is a hydrogen atom or .beta.-D-ribofuranosyl group of the formula ##STR2## and R.sub.3 is hydroxyl, amino-NH.sub.2 or acylamino group --NHR.sub.4 in which R.sub.4 is an acyl group, and n is a whole number of 1 to 4, may be produced by subjecting the corresponding O-((S)-.alpha.-substituted-.omega.-aminoacyl)-neamine or -ribostamycin of the formula ##STR3## or its hydroxyl-masked and maino-masked form, to the action of a basic medium to produce an acyl-migration product of the formula: ##STR4## and, optionally converting the amino-masking groups into hydrogen atoms and also the hydroxyl-masking group into hydroge atom in a known manner if said amino-masking groups and said hydroxyl-masking groups are present in the acyl-migration product. The 1-N-((S)-.alpha.-substituted-.omega.-aminoacyl)-neamine or -ribostamycin produced is characterized by its useful activity inhibitory to the growth of bacteria resistant to the parent substance neamine or ribostamycin.
摘要:
An 1-N-((S)-.alpha.-substituted-.omega.-aminoacyl)-neamine or -ribostamycin of the formula: ##STR1## wherein R is a hydrogen atom or .beta.-D-ribofuranosyl group of the formula ##STR2## and R.sub.3 is hydroxyl, amino-NH.sub.2 or acylamino group --NHR.sub.4 in which R.sub.4 is an acyl group, and n is a whole number of 1 to 4, may be produced by subjecting the corresponding O-((S)-.alpha.-substituted-.omega.-aminoacyl)-neamine or -ribostamycin of the formula ##STR3## or its hydroxyl-masked and amino-masked form, to the action of a basic medium to produce an acyl-migration product of the formula: ##STR4## and, optionally converting the amino-masking groups into hydrogen atoms and also the hydroxyl-masking group into hydrogen atom in a known manner if said amino-masking groups and said hydroxyl-masking groups are present in the acyl-migration product. The 1-N-((S)-.alpha.-substituted-.omega.-aminoacyl)-neamine or -ribostamycin produced is characterized by its useful activity inhibitory to the growth of bacteria resistant to the parent substance neamine or ribostamycin.
摘要:
This invention relates to a process for the preparation of coformycin, 3-(.beta.-D-ribofuranosyl)-6,7,8-trihydroimidazo[4,5-d][1,3]diazepin-8(R)-ol, through a synthetic route from a new derivative of 9-.beta.-D-ribofuranosyl-purine and other synthetic intermediates involved in the process and their preparation.
摘要:
In a universal joint, a cross shaft member includes four shaft parts forming a cross-shape. Each of four bearing cups corresponding respectively to the shaft parts has a hollow-cylindrical shape having a bottom and is rotatably mounted to the corresponding shaft part through a roller disposed between an inner peripheral surface of the each bearing cup and an outer peripheral surface of the corresponding shaft part. Each bearing cup includes an inner bottom surface in sliding contact with a distal end surface of the corresponding shaft part, wherein the sliding contact is in an annular region encompassing a central axis of the corresponding shaft part. The distal end surface of each shaft part is formed with an annular groove encompassing the central axis of the first shaft part for storing oil.
摘要:
The disclosed windfarm control system comprising a windfarm and a central controller; the windfarm including plural wind power generators whose rotational speeds are variable, plural aerographs disposed in the vicinity of the wind power generators to measure the directions and powers of the wind at the sites of the generators, and plural local controllers disposed in the vicinity of the wind power generators to control the output of the wind power generators by controlling the rotational speeds of the generators; wherein the central controller calculats the control level which maintains the output of the windfarm constant for a predetermined time period and instructs the local controllers to control the rpm's of the wind power generators in accordance with the control level.
摘要:
In a controller for a windfarm including a plurality of wind turbine generators controllable in rotation frequency and pith of blades of the wind turbine generators, coupled to a grid through a transmission line, an anemometer is provided to each wind turbine generator to transmits wind direction and wind speed data to a central controller which process the wind direction and wind speed data to transmit an output command each wind turbine generator. The central controller predicts, on the basis of the wind speed detected by the upstream wind turbine generator, variation in wind speed at other wind turbine generators to control the output of the windfarm. The output power may be limited or charging energy as rotation energy of blades and discharging the rotation energy as output power in addition to a battery unit for averaging.