Agency of Industrial Science and Technology

Director-general of the Agency of Industrial Science and Technology

Japan As Represented by Secretary of Agency of Industrial Science and Technology

Masao Shibata

Hideki Ohba

Tsuyoshi Sakaki

Imre Sallay

Toshihisa Sumi

Toru Ikegami

Sung Soo Park

Yasuhiro Yamada

Hidemasa Honda

Takeshi Imamura

Seiji Arita

Disclosed is an economical method for the preparation of chondroitin sulfates A and C useful as an effective ingredient of medicaments from fish scales as a waste material discharged from fishery in large quantities. Fish scales are enzymatically decomposed in an aqueous medium in the presence of a protease to isolate the chondroitin sulfate compounds and by-product polypeptides followed by removal of the by-product polypeptides from the aqueous solution by a cation-exchange treatment and then the aqueous solution of the chondroitin sulfate compounds is subjected to fractional precipitation by the addition of ethyl alcohol as the precipitant.

Method for the preparation of chondroitin sulfate compounds

Disclosed is an efficient and economical method for the preparation of N-glycolyl neuraminic acid in a high purity from an inexpensive abundant source material. The method comprises dispersing body tissues of an echinodermatous marine animal Cucumaria echinata in an aqueous medium, preferably, using a dry powder of the tissues prepared in advance, in which the tissues are proteolytically decomposed to isolate N-glycolyl neuraminic acid in the form of an aqueous solution containing polypeptides as a by-product, followed by separation of N-glycolyl neuraminic acid from the aqueous solution by removing the polypeptides and purification of the compound in a process utilizing an ion-exchange treatments.

Method for the preparation of N-glycolyl neuraminic acid from Cucumaria

The invention provides a method for the preparation of a pitch spinnable into pitch filaments as a precursor of carbon fibers starting from a pitch material such as coal tar and coal tar pitch. Different from the conventional procedure involving hydrogenation of the starting pitch, the starting pitch in the inventive method is first heated together with an aromatic oil, preferably, in the presence of a cracking catalyst such as silica-alumina and zeolite at 350.degree. to 500.degree. C. for 10 to 60 minutes under no pressurization with hydrogen and, after removal of insoluble materials, then heated at a temperature of 430.degree. to 600.degree. C. The thus obtained pitch for spinning has good spinnability and the carbon fibers prepared from the pitch have a unique microscopic structure and excellent physical properties exceeding by far the conventional pitch-based carbon fibers and approximating the HP-grade carbon fibers prepared from polyacrylonitrile fibers.

Method for the preparation of pitches for spinning carbon fibers

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Ogoori, Japan

Masao Shibata