Isamu Yanagisawa

Simultaneous separation and sensitive determination of free fatty acids in blood plasma by high-performance liquid chromatography

The quantitative determination of saturated and unsaturated fatty acids (ranging from acetic acid to lignoceric acid) in biological samples is presented. The secondary amine group of 5-(dimethylamino)-1-naphthalenesulponyl-semipiperazide (dansyl-semipiperazide) reacts with the carboxyl group of the fatty acids to form an amide linkage in order to obtain fluorescent derivatives of the acids. The fluorescent derivatives are analysed by high-performance liquid chromatography (HPLC) using an internal standard.

Anticholinesterase Action of a Bromine Compound Isolated from Human Cerebrospinal Fluid

Abstract: L‐l‐Methylheptyl‐γ‐bromoacetoacetate was found to be a competitive inhibitor of the acetylcholines‐terases (electric eel, Ki= 17.2 μM; rat brain, Ki= 32.6 μM) and of butyrylcholinesterase (horse serum, Ki= 1.2 μM). The L‐isomer was a more effective inhibitor than the D‐isomer. The bromine atom at the γ‐position of the acidic moiety, the specific length of the carbon chain constituting the secondary alcohol moiety, and the presence of the ketone radical at the acidic moiety of the ester were necessary for the anticholinesterase action. 1‐Methyl‐heptyl‐γ‐bromoacetoacetate formed a complex with acetylcholinesterase or butyrylcholinesterase without hydrolysis of its own molecule.