Tyrosinase Inhibitory Activities of Meso-dihydroguaiaretic Acid from Machilus thunbergii

국문 초록 (Abstract)

후박나무(녹나무과)는 한국과 일본 등지에 서식하는 상록 교목으로 한국, 중국, 일본에서 부종, 복통, 복부 팽만 등의 질병 치료를 위해 오랫동안 사용되어오고 있다. 본 연구에서는 후박나무 껍질을 메탄올에 추출하고 메탄올 추출물을 헥산, 클로로포름, 부탄올에 순차적으로 분획하였다. 클로로포름 분획물로부터 2종의 화합물을 분리하였으며 분리된 화합물1과 2의 구조는 ¹H-, <SUP>13</SUP>C-NMR과 참고 문헌 데이터에 의해 dibenzylbutane lignin 화합물인 macelignan (1)과 meso-dihydroguaiaretic acid (2)로 동정되었다. 분리된 화합물들의 tyrosinase 저해 활성을 측정한 결과, 화합물 2는 tyrosinase 저해 활성 중 monophenolase (IC50 = 10.2 μM)에 대해 높은 저해활성을 나타내는 경쟁적 저해제였으며 효소에 결합하는 화합물 2의 저해 상수(Ki 값)는 4.8 μM였다. 따라서 meso-dihydroguaiaretic acid (2)는 멜라닌 생합성과 관련된 피부 질환 치료를 위한 잠재적 후보가 될 수 있을 것으로 판단된다.

다국어 초록 (Multilingual Abstract)

Machilus thunbergii (Lauraceae) is an evergreen tree cultivated in Korea and Japan. M. thunbergii has long been used as a traditional medicine in Korea, China, and Japan to treat various diseases, including edema, abdominal pain, and abdominal distension. In this study, dried stem bark of M. thunbergii extracted in methanol and extract was partitioned into n-hexane, CHCl₃, and BuOH. The CHCl₃-soluble extracts chromatographed on silica gel column using a CHCl₃/acetone and n-hexane/EtOAc mixture to afford Compound 1 and 2. Two dibenzylbutane lignans, macelignan (1) and meso-dihydroguaiaretic acid (2), were isolated from the CHCl₃-soluble extract of M. thunbergii stem bark. The structures of 1 and 2 were determined by <SUP>1</SUP>H- and <SUP>13</SUP>C-NMR spectroscopic data analyses and a comparison with literature data. The tyrosinase inhibitory activity of the isolated compounds was evaluated. Among these compounds, Compound 2 strongly inhibited the monophenolase (IC50=10.2 μM) activity of tyrosinase. A kinetic analysis showed that Compound 2 was a competitive inhibitor. The apparent inhibition constant (Ki) for Compound 2 binding to free enzyme was 4.8 μM. Based on these results, it can be concluded that meso-dihydroguaiaretic acid (2) is a potential candidate for the treatment of melanin biosynthesis-related skin diseases.

목차 (Table of Contents)

• Introduction
• Materials and Methods
• Results and Discussion
• References
• 초록