Effects of Shikonin Pigments from the Roots of Lithospermum eryhrorhizon on Rabbit Platelets

자근으로부터 혈소판에 작용하는 천연색소물질에 관한 연구

Lithospermum erythrorhyzon has been used as a red fooddye and traditional Chinese medicine to treat wounds, skin diseases and burns. Platelet activation plays an important role in thrombosis and haemostasis. Here, we studied the inhibition of platelet activation and its active compound from the root of Lithospermum erythrorhyzon. Its ethyl acetate extract inhibited the aggregation of washed rabbit platelets induced by collagen or thrombin. Five naphthoquinone pigments , shikonin , acetylshikonin , is obutylshikonin, $\alpha$-methyl-n-butylshikonin and $\beta$,$\beta$-dimethylacrylshikonin were isolated by means of high pressure liquid chromatography. The structures were determined by comparison of their proton nuclear magnetic resonance spectra. The potency of their inhibition was in the following order : $\beta$,$\beta$-dimethylacrylshikonin$\geq$$\alpha$-methyl-n-butylshikonin>isobutylshikonin>acetylshikonin>shikonin. It is suggested that the size of the aliphatic hydroxy group of shikonin is important for the enhancement of potency.

최근 동물성 식품 및 지방 섭취 증가로 인한 현대인의 식생활 변화로 혈소판 활성화가 직접적 원인인 뇌 .심혈관질환의 사망률이 증가되고, 성인병 예방과 치료의 대처방안으로 식품의 기능성에 대한 관심이 높아짐에 따라서 천연착색료이며 항균, 항암 작용이 있는 자근(Lithospermum erythrorhizon)으로부터 추출, 분리 . 정제한 분획물에서 혈소판 활성화 억제작용이 있는 생리활성물질을 분리 . 동정하였다 자근에서 methanol, n-hexane, ethyl acetate 등의 용매추출물과 methanol 추출물에 NaOH프 처리한 n-hexane 추출물에 대한 혈소판 응집 억제작용은 collagen의 응집작용에 대하여 n-hexane재추출물이, thrombin의 응집작용에 대하여 ethyl acetate추출물이 큰 억제작용을 보였고, 이러한 추출물에서 컬림 및 HPLC로 분리 .정제한 5개 물질의 화학구조를 IH과 13C-NMR 스펙트라 분석한 결과 shikonin, acethylshi onin, isobutylshikonin, $\alpha$-methyl-n-butylshikonin, $\beta$,$\beta$-dimethylacrylshikonin을 확인하였고, 혈소판 응집 억제작용은 $\beta$,$\beta$-dimethylacrylshi onin$\geq$$\alpha$-methyl-n-butylshikonin>isobutylshikonin>acetylshikonin>shikonin순으로 나타났다. 이상의 결과로부터 자근색소의 생리활성은 shikonin유도체이며 11번 탄소에 치환된 aliphatic 기의 탄소수가 많을수록 억제작용이 강하게 나타난다고 사료된다.