Toyo Soda Manufacturing Co., Ltd.

Tosoh Corporation

(zaidanhojin) Sagami Chemical Research Center

Sagami Chemical Research Center

Ajinomoto Co., Ltd.

Holland Sweetener Company, V.o.f.

Toyo Soda Mfg. Co., Ltd.

Sagami Chem. Rsch. Cntr.

Kiyotaka Oyama

Tsuneo Harada

Yuji Nonaka

Shigeaki Irino

Akira Tokuda

Heijiro Satoh

Yoshikazu Isowa

Keiichi Kihara

Kaoru Mori

Muneki Ohmori

Tetsuya Ichikawa

Tuneo Harada

Shigeaki Nishimura

Masashige Kubo

Hidetoshi Wakamatsu

Yukio Kunisawa

Masao Nakamura

Masao Nakano

Kazuhiko Sekizawa

Hideo Takeda

Katsumi Sugiyama

Takumi Kagawa

Hiroko Sato

Fumio Okisaki

Toshio Hironaka

Yasuhiro Kurauchi

Mitsuru Takahashi

Hideaki Kurita

Masanari Sato

Theodorus J Van Dooren

Wilhelmus J Van Den Tweel

Satoshi Fujii

Takao Matsuba

Hideo Shuyama

Seiichi Asano

Tsutomu Hashimoto

Norio Hagi

Hideotoshi Wakamatsu

Hiroshi Shimizu

Ken-ichi Fukuda

Peter J Quaedflieg

Michihiro Akazawa

Shin-ichiro Nakamura

Johanna C Smeets

Shuya Takasuga

Koji Kawabata

A method for making a stabilized neutral metalloprotease enzyme composition is described in which a neutral metalloprotease and an aqueous solution are combined to obtain a solution or slurry thereof, whereby the stabilized neutral metalloprotease enzyme composition is obtained. The aqueous solution contains an N-protected amino acid, or an N-protected amino acid is added thereto. The invention also provides a stabilized neutral metalloprotease composition, and a method of transporting the stabilized neutral metalloprotease composition.

Stabilized neutral metalloprotease composition, a method of making the

The invention relates to a process for the preparation of N-protected-L-aspartyl-L-phenylalanine methyl ester by enzymatic coupling of an N-protected-L-aspartic acid and L- or DL-phenylalanine methyl ester in an aqueous solution with formation of a precipitate using a thermolysin-like protease enzyme, wherein a water-immiscible organic solvent is added to and blended with the reaction system during the formation of the precipitate in the course of the coupling reaction, which organic solvent has a relatively high affinity for the precipitate. The process is particularly suitable as a continuous process. The method results in lower enzyme deactivation during and after the enzymatic coupling reaction and in larger and thicker precipitated crystals.

Enzymatic coupling reaction of N-protected-L-aspartic acid and

The invention relates to a process for the preparation of N-benzyloxycarbonyl-.alpha.-L-aspartyl-L-phenylalanine methyl ester by enzymatic coupling of N-benzyloxycarbonyl-L-aspartic acid and L-phenylalanine methyl ester in an aqueous medium with formation of a precipitate, the coupling reaction being effected with (virtually) equimolar quantities of N-benzyloxycarbonyl-L-aspartic acid and L-phenylalanine methyl ester under the influence of a neutral protease at an initial pH of from 4.5 to 6.0 and in the presence of from 3 to 25%, calculated as per cent by weight based on the total reaction mixture, of an alkali metal salt, alkaline earth metal salt or ammonium salt.

Enzymatic coupling of L-phenylalanine methyl ester and

A method for crystallizing .alpha.-L-aspartyl-L-phenylalanine methyl ester from a hot aqueous solution containing .alpha.-L-aspartyl-L-phenylalanine methyl ester by cooling is disclosed, which comprises (i) continuously supplying a hot aqueous solution of .alpha.-L-aspartyl-L-phenylalanine methyl ester having a concentration such that the content of L-aspartyl-L-aspartyl-L-phenylalanine methyl esters is less than 0.6% by weight based on the weight of .alpha.-L-aspartyl-L-phenylalanine methyl ester in said solution, or if the content of L-aspartyl-L-aspartyl-L-phenylalanine methyl esters is 0.6% by weight or more based on the weight of .alpha.-L-aspartyl-L-phenylalanine methyl ester in said solution, to a crystallization vessel the temperature of which is lowered to that corresponding to the solubility of .alpha.-L-aspartyl-L-phenylalanine methyl ester or less, and (ii) continuously discharging the formed slurry from the crystallization vessel.

Method for crystallizing .alpha.-L-aspartyl-L-phenylalanine methyl ester

A method for preparing .alpha., .beta.-unsaturated carboxylic acids of the formula

Method for preparation of .alpha., .beta.-unsaturated carboxylic acid

Disclosed is a shaped zeolite catalyst used for liquid phase organic reactions. The shaped zeolite catalyst is composed of substantially spherical particles having a particle diameter substantially in the range of from 70 to 300 .mu.m, and which has fine pores having a pore volume of 0.4 to 1 cc per gram of the shaped catalyst and a median pore diameter based on the pore volume of 1,000 to 5,500 .ANG..

Shaped zeolite catalyst for liquid phase organic reactions

A method for purifying a dipeptide ester by electrolysis in an electrolytic cell comprising an anode compartment, a cathode compartment and a central compartment partitioned by anion exchange membranes, which comprises supplying an aqueous dipeptide ester solution containing an inorganic acid to the central compartment defined by said anion exchange membranes, an aqueous solution containing a basic substance or an aqueous electrolyte solution containing a basic substance to the cathode compartment and an aqueous electrolyte solution to the anode compartment, supplying hydroxyl ions from the cathode compartment to the central compartment through the anion exchange membrane to neutralize the aqueous dipeptide ester solution containing the inorganic acid and removing anions of the inorganic acid in the aqueous dipeptide ester solution from the central compartment to the anode compartment through the anion exchange membrane.

Method for purifying a dipeptide ester

A 4,4'-bis(phthalimido)diphenyl sulfone compound having the formula: ##STR1## wherein X is a halogen atom, k=0 to 4, l=0 to 4, m=0 to 4 and n=0 to 4, provided k+l+m+n&gt;1.

4,4'-bis(phthalimido)diphenyl sulfone compounds, processes for their

A method for producing 4,4'-dibromobiphenyl, which comprises reacting biphenyl and from 2 to 3 mol times, relative to biphenyl, of bromine in a halogenated hydrocarbon solvent in the presence of a catalyst which is a simple substance of an element selected from the group consisting of antimony, titanium, tin and zinc, or a compound of the element.

Method for producing 4,4'-dibromobiphenyl

A process for producing dry .alpha.-L-aspartyl-L-phenylalanine methyl ester, which comprises drying wet crystals of .alpha.-L-aspartyl-L-phenylalanine methyl ester by means of an air having an absolute humidity of at least 0.015 kg/kg or at most 0.01 kg/kg.

Process for producing dry .alpha.-L-aspartyl-L-phenylalanine methyl ester

A process for producing stable .alpha.-L-aspartyl-L-phenylalanine methyl ester, which comprises heat-treating crystals of .alpha.-L-aspartyl-L-phenylalanine methyl ester having a water content of from 5 to 15% by weight based on wet crystals, at a temperature of higher than 50.degree. C. and lower than 80.degree. for at least 30 minutes.

Process for producing stable .alpha.-L-aspartyl-L-phenylalanine methyl

A method for purifying a dipeptide ester by electrolysis in an electrolytic cell comprising an anode compartment, a cathode compartment and a central compartment partitioned by ion exchange membranes, which comprises supplying an aqueous dipeptide ester solution containing organic acids to the central compartment defined by anion and cation exchange membranes or by anion exchange membranes and an aqueous electrolyte solution to the cathode and anode compartments, and electrically removing the organic acids from the central compartment to the anode compartment through the anion exchange membrane.

A process for producing dry .alpha.-L-aspartyl-L-phenylalanine methyl ester having an improved solubility from wet crystals of .alpha.-L-aspartyl-L-phenylalanine methyl ester having a water content of at least 20% by weight, which comprises drying the wet crystals at a temperature of higher than 50.degree. C. to obtain moist crystals having a water content of less than 20 and more than 15% by weight, then drying the moist crystals at a temperature of not higher than 50.degree. C. to obtain semi-dry crystals having a water content of less than 5% by weight, and further drying the semi-dry crystals at a temperature of higher than 50.degree. C. to obtain dry crystals of .alpha.-L-aspartyl-L-phenylalanine methyl ester.

Process for producing alpha-aspartyl-l-phenylalanine methyl ester having

A method for racemizing an optically active amino acid, which comprises heating the optically active amino acid in an aqueous solution under an alkaline condition in the presence of an alkali metal salt.

Method for racemizing an optically active amino acid

A process for producing DL-phenylalanine by reacting an .alpha.-halogeno-.beta.-phenylpropionic acid represented by the general formula: ##STR1## where X is a halogen atom, or its salt, with ammonia, characterized in that the reaction is conducted while supplying the .alpha.-halogeno-.beta.-phenylpropionic acid or its salt into aqueous ammonia charged in a reactor in advance.

Process for producing DL-phenylalanine

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Hikari, Japan

Kiyotaka Oyama