The lyophilization of the solution extracted from 60 percent of acetone applied to persimmon leaves, the compounding process in accordance with the solution's concentration, and the gel filteration through Sephadex G-50 of biologically activated substances obstructing enzyme activity, such as tyrosinase, xanthine oxidase, and angiotesin converting enzyme (ACE) led to the assumption that polyphenol was the compound serving as biologically activated substances obstructing enzyme activity. Xanthine oxidase involved in pruine metabolism oxidizes hypoxanthine to xanthine and xanthine to uric acid. In the continuous study for natural compound, nine flavan-3-ols have been isolated from the persimmon leaves. The structures of (+)-catechin, (+)-gallocatechin, procyanidin B-1, pyrocyanidin C-1, prodelphinidin B-3, gallocatechin-(4α→8)-catechin, procyanidin B-7-3-O-gallate, procyanidin C-1-3'-3'-3'-O-trigallate and (-)-epigallocatechin-(4α→8)-epigallocatechin-(4α→8)-catechin were established by NMR and their inhibitory effect on xanthine oxidase activity was investigated. Procyanidin B-7-3-O-gallate, (-)-epigallocatechin-(4α→8)-epigallocatechin-(4α→8)-catechin and procyanidin C-1-3'-3'-3'-O-trigallate showed 94%, 90.69%, 80.90% inhibition at 100 (μ)M and inhibited on the angiotensin converting enzyme respectively. Procyanidin B-7-3-O-gallate and procyanidin C-1-3'-3'-3'-O-trigallate showed 66%, 63% inhibition at 100 (μ)M and inhibited on the xanthine oxidase competitively. Procyanidin C-1-3'-3'-3'-O-trigallate showed 70% inhibition at 100 (μ)M and inhibited on the tyrosinase competitively.

Comparing and analysing the productivity and the main ingredients of persimmon leaves by cultivars were conducted to improve the quality and productivity of the per-simmon leaf tea. As a result of the survey, Dungsi was decidedly good in growth co-ndition of survival rate, stem diameter and the number of shoots etc. Also , DUngsi had the highest leaf productivity of 567 leaves and the leaf weight of 1.98 kg per one plant after three years of planting . On accounts of productivity, ingredient analysis and panel test etc. we collectively through that Dungsi was the best cutltivar for the persimmon leaf tea.

찌는 시간을 달리하여 절단한 차는 색과 향이 3분과 5분간을 찐 후 절단하였을 때 우수하였다. 가용성 고형분 함량, 추출 수율이 증가됨에 따라 맛의 기호성은 증진되었고, 탁도와 갈색도, 색도의 증가는 색깔의 기호성을 증진 시켰다. 3분간 찐 후 절단하여 시간별로 볶은차와 5분간 찐 후 절단하여 시간을 다르게 볶은차는 전체적 기호성이 5분간 볶았을 때 우수하였고, 가용성 고형분 함량, 추출수율, 탁도, 갈색도, 전체 색도는 볶는 시간에 비례하여 증