Leu Yann-Lii, Hwang Tsong-Long, Hu Jiuan-Wen, Fang Jia-You
Natural Products Laboratory, Graduate Institute of Natural Products, Chang Gung University, Kweishan, Taoyuan, Taiwan.
Phytother Res. 2008 Apr;22(4):552-6. doi: 10.1002/ptr.2324.
Four anthraquinones, physcion (1), emodin (2), citreorosein (3) and anthraglycoside B (6), and two stilbenes, resveratrol (4), and piceid (5), were isolated previously from the root of Polygonum cuspidatum. These bioactive compounds were examined for their antityrosinase potency. No antityrosinase activity was detected with treatment using stilbenes. On the other hand, the anthraquinones showed moderate to strong inhibition of tyrosinase. Physcion exhibited the most potent tyrosinase inhibition among the four anthraquinones examined, which was comparable to kojic acid. The ability of anthraquinones to permeate the skin was also examined. Based on the same thermodynamic activity, physcion showed a higher permeation compared with emodin (48-fold), suggesting it as a potent candidate for dermal use. As naturally occurring tyrosinase inhibitors, anthraquinones from P. cuspidatum may be useful as skin-whitening agents to inhibit tyrosinase for dermal use.
四种蒽醌类化合物，大黄素甲醚（1）、大黄素（2）、柠橙玫瑰素（3）和蒽糖苷B（6），以及两种芪类化合物，白藜芦醇（4）和白藜芦醇苷（5），先前已从虎杖根中分离得到。对这些生物活性化合物的抗酪氨酸酶活性进行了检测。使用芪类化合物处理未检测到抗酪氨酸酶活性。另一方面，蒽醌类化合物表现出对酪氨酸酶的中度至强烈抑制作用。在检测的四种蒽醌类化合物中，大黄素甲醚对酪氨酸酶的抑制作用最强，与曲酸相当。还研究了蒽醌类化合物渗透皮肤的能力。基于相同的热力学活性，大黄素甲醚的渗透率比大黄素高（48倍），表明它是一种潜在的皮肤用药候选物。作为天然存在的酪氨酸酶抑制剂，虎杖中的蒽醌类化合物可能作为皮肤美白剂用于抑制皮肤中的酪氨酸酶。
