Abstract

Aqueous ethanol extracts of powdered stems of Dendrobium loddigesii afforded three new phenolics including threo-7-O-ethyl-9-O-(4-hydroxyphenyl)propionyl-guaiacylglycerol (1), (R)-4,5,4ʹ-trihydroxy-3,3ʹ,α-trimethoxybibenzyl (2) and (S)-5,5′,7-trihydroxy-3′,4′-dimethoxyflavanone (3), together with eleven known analogues. Their structures were determined by extensive spectroscopic analysis. To identify natural antioxidants, whitening, and anti-aging agents, the abilities of these phenolics were assessed to scavenge the 1,2-diphenyl-2-picrylhydrazyl (DPPH) radical, their abilities to inhibit tyrosinase production, and their abilities to stimulate collagen production by human dermal fibroblasts-adult (HDFa) assay. It was found that compounds 1, 4–8, 13 and 14 exhibited significant DPPH radical scavenging activities, compound 10 exhibited tyrosinase inhibitory activity (IC₅₀ 37.904 μg/mL), and compound 9 showed significant collagen production with an EC₅₀ value of 3.182 μg/mL. These results suggest that phenolic constituents from D. loddigesii may be candidate antioxidants, skin-whitening and/or anti-aging agents.

Graphic Abstract

中文翻译：

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铁皮石end具有抗氧化，酪氨酸酶抑制和抗衰老作用的酚类成分。

抽象

的粉状茎的含水乙醇提取物美花石斛，得到三个新的酚类化合物，包括苏型7- O-乙基- 9- O-（4-羟基苯基）丙酰guaiacylglycerol（1），（[R）-4,5,4'三羟基3,3ʹ，α-三甲氧基联苯甲基（2）和（S）-5,5'，7-三羟基-3'，4'-二甲氧基黄酮（3），以及十一个已知的类似物。通过广泛的光谱分析确定了它们的结构。为了鉴定天然抗氧化剂，增白剂和抗衰老剂，评估了这些酚类的能力以清除1,2-二苯基-2-吡啶并肼基（DPPH）自由基，抑制酪氨酸酶产生的能力以及刺激胶原蛋白的能力。人皮肤成纤维细胞-成人（HDFa）分析检测生产。结果发现，化合物1，4 - 8，13和14显示出显著DPPH自由基清除活性，化合物10表现出酪氨酸酶抑制活性（IC ₅₀ 37.904微克/毫升），和化合物9显示出明显的胶原蛋白生成，EC ₅₀值为3.182μg/ mL。这些结果表明，来自罗氏梭菌的酚类成分可能是候选的抗氧化剂，美白皮肤和/或抗衰老剂。

图形摘要