Phenolic Compounds of Piper betle Flower as Flavoring and Neuronal Activity Modulating Agents

Piper betle is a tropical plant from Southeast Asia. The flower of this plant is the major ingredient which gives flavor and other properties to a special chewing food, betel quid, which is quite popular in Taiwan. The essential oil of Piper betle flower was extracted by vacuum steam distillation, analyzed by GC and identified by GC co-chromatography, GC-MS and IR. Safrole and myrcene were the major compounds found in the essential oil (27.6% and 26.4%, respectively). Safrole, hydroxychavicol, eugenol, isoeugenol, and eugenol methyl ester were found to be the major phenolic compounds by HPLC and TLC analyses. Results of the catecholamine secretion experiment, a test for neuronal modulating activity, showed that eugenol, isoeugenol and hydroxychavicol are strong nerve stimulators while safrole and eugenol methyl ester are weak.