Hypotensive Compounds Isolated from Alcohol Extract of the Unossified Horn of Cervus elaphus L. var. xanthopygus MILNE-EDWARG (Rokujo). I. Isolation of Lysophosphatidyl Choline as a Hypotensive Principle and Structure-Activity Study of Related Compounds

Abstract

By the use of spontaneously hypertensive rats (SH rats) as a screening system, two hypotensive compounds were isolated from alcohol extract of the unossified horn of Cervus elaphus L. var. xanthopygus (Rokujo). One of the two compounds was identified as lysophosphatidyl choline (LPC). It was shown by gas chromatography that palmitic acid (C_{16 : 0}) accounted for about half of the fatty acid content. Next, the effects of various LPCs on SH rats were examined. Eleven LPCs with C_{10 : 0} to C_{20 : 0} fatty acids were examined, and all except for those with C_{10 : 0} and C_{20 : 0} fatty acids showed the hypotensive effect (3 mg/kg, i.v.). In particular, C_{14 : 0} and C_{16 : 0}-LPC showed rather potent activity. On the other hand, of the six LPCs with unsaturated fatty acids, only C_{16 : 1}-LPC showed the hypotensive effect (3 mg/kg). It was concluded that at least a part of the hypotensive action of alcohol extract of Rokujo is due to LPC.