Abstract: A novel process which can simply prepare a crosslinked hyaluronic acid gel having a small crosslinking agent content and exhibiting excellent viscoelasticity is provided. A process for preparing a crosslinked hyaluronic acid gel, comprising stirring and mixing a mixture containing 10 W/V % or more of hyaluronic acid, a crosslinking agent and water under acidic or alkaline condition.

Abstract: The present invention provides a cationic polymer which is much closer to the component of a human body, and capable of forming a polyion complex together with an anionic material such as hyaluronic acid. The cationized hyaluronic acid of the present invention is a hyaluronic acid wherein at least one part of hydroxylic hydrogen atoms of hyaluronic acid is replaced with a group having a quaternary ammonium cation group. The cationized hyaluronic acid can be synthesized by reacting hyaluronic acid with a cationizing agent such as glycidyltrialkyleammonium halide. The cationized hyaluronic acid of the present invention can form a polyion complex gel with hyaluronic acid or the like in the presence of water.

Abstract: ?-Ketol unsaturated fatty acid derivatives represented by the following formula (1), ?-ketol unsaturated fatty acid amide derivatives represented by the following formula (6), and plant growth regulators containing, as the active ingredient, at least one of these derivatives: wherein R1 represents linear C1-5 alkyl; R represents hydrogen, etc.; R3 represents hydrogen, etc.; R4 represents hydrogen, etc.; R5 represents hydrogen, etc.; n is an integer from 3 to 15; and the carbon atoms at the A- and B-positions may be in either (R)- or (S)-configuration; and wherein R7 represents C1-17 alkyl, etc; R8 represents hydrogen, etc.; R9 represents ?-ketolalkylene; and R10 represents specific divalent linear hydrocarbyl.

Abstract: [PROBLEMS] A novel process which can simply prepare a crosslinked hyaluronic acid gel having a small crosslinking agent content and exhibiting excellent viscoelasticity is provided. [MEANS TO SOLVE] A method of producing cross-linking hyaluronic acid gel, comprising stirring and mixing a mixture containing 20 W/V % or more of hyaluronic acid, a crosslinking agent and water under acidic or alkaline condition.

Abstract: ?-Ketol unsaturated fatty acid derivatives represented by the following formula (1), ?-ketol unsaturated fatty acid amide derivatives represented by the following formula (6), and plant growth regulators containing, as the active ingredient, at least one of these derivatives: wherein R1 represents linear C1-5 alkyl; R2 represents hydrogen, etc.; R3 represents hydrogen, etc.; R4 represents hydrogen, etc.; R5 represents hydrogen, etc.; n is an integer from 3 to 15; and the carbon atoms at the A- and B-positions may be in either (R)- or (S)-configuration; and wherein R7 represents C1-17 alkyl, etc; R8 represents hydrogen, etc.; R9 represents ?-ketolalkylene; and R10 represents specific divalent linear hydrocarbyl.

Abstract: ?-Ketol unsaturated fatty acid derivatives represented by the following formula (1), ?-ketol unsaturated fatty acid amide derivatives represented by the following formula (6), and plant growth regulators containing, as the active ingredient, at least one of these derivatives: wherein R1 represents linear C1-5 alkyl; R represents hydrogen, etc.; R3 represents hydrogen, etc.; R4 represents hydrogen, etc.; R5 represents hydrogen, etc.; n is an integer from 3 to 15; and the carbon atoms at the A- and B-positions may be in either (R)- or (S)-configuration; and wherein R7 represents C1-17 alkyl, etc; R8 represents hydrogen, etc.; R9 represents ?-ketolalkylene; and R10 represents specific divalent linear hydrocarbyl.

Abstract: &agr;-Ketol unsaturated fatty acid derivatives represented by the following formula (1), &agr;-ketol unsaturated fatty acid amide derivatives represented by the following formula (6), and plant growth regulators containing, as the active ingredient, at least one of these derivatives: 1

Abstract: The present invention provides an efficient synthetic method of &agr;-ketol unsaturated fatty acid having a double bond at a &bgr;-position to the ketone group thereof. It comprises the steps of: preparing compound (4) by reacting monosubstituted acetylene (2) with epoxide (3); and preparing &agr;-ketol unsaturated fatty acid (1) from said compound (4) as shown in Reaction Formula 1: wherein R1 represents an alkyl group of 1-18 carbon atoms or an aliphatic hydrocarbon group of 2-18 carbon atoms having 1-5 double or triple bonds at given positions; R2 represents a protecting group for a hydroxyl group; R3 represents a protecting group for a carboxyl group; R is identical to R1 or, when R1 has one or more triple bonds, represents an aliphatic hydrocarbon group in which each triple bond of R1 is converted to a double bond; and A represents an alkylene group of 1-18 carbon atoms.

Abstract: The present invention provides an efficient synthetic method of &agr;-ketol unsaturated fatty acid having a double bond at a &bgr;-position to the ketone group thereof.

Abstract: An external preparation for skin comprising at least one member selected from the group consisting of escinol and its salts represented by the following constitutional formula (1): ##STR1## (wherein R.sup.1 is hydrogen atom or hydroxyl group and R.sup.2 is pyranose residue.)Due to the effect of escinol which characterizes the present invention, the external preparation in accordance with the present invention is excellent in whitening effect and has a high safety.

Abstract: An external preparing for skin comprising one or more than two types of 2-hydroxy benzoic acid derivative and/or salt thereof represented by the following formula: ##STR1## wherein R is an alkoxy group or alkyl group in the formula. The external preparation for the skin according to the present invention has a suppression effect on melanine generation by inhibition of tyrosinase activity. Accordingly, an excellent bleaching effect based upon the suppression of chromatosis and a high degree of safety can be obtained.