There is now a preference for hair dye products containing natural dyes because they are safer for human use. Teak leaves contain flavonoids, anthraquinones and naphthoquinones, and their extracts can be used as natural dyes. The objective of this research was to evaluate the use of teak leaf extracts as natural hair dyes. This research was carried out on both young and mature teak leaves that were extracted either with water or with ethanol-water mixtures using the decoction method. The colour substances in the extracts were studied by quantifying the flavonoid and anthraquinone content, and identified using liquid chromatography-mass spectrometry (LC-MS); the colour values were measured with the CIELab system. The solubility, stability and hair dyeing efficacy of the extracts were assessed. The results showed that young leaf extract is redder with a higher total flavonoid content than mature leaf extract. Fifty percent ethanol was the best solvent for extracting the high flavonoids from teak leaves. Polysorbate 20 significantly increased the water solubility of both young and mature leaf extracts. Hair dyed with young leaf extract became reddish brown, while hair dyed with mature leaf extract became brown. Stability testing found some flavonoid degradation of the extracts, but only slight colour changes occurred in the extracts. The LC-MS profiles showed high-intensity flavonoid peaks that could be applied to control the colour quality of the extracts with other parameters. These results demonstrate that teak leaf extracts are effective natural hair dyes that can be used in the development of hair dye products.

中文翻译：

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利用 Tectona grandis（柚木）叶提取物作为天然染发剂

现在人们更喜欢含有天然染料的染发产品，因为它们对人类使用更安全。柚木叶含有黄酮类、蒽醌类和萘醌类，其提取物可用作天然染料。本研究的目的是评估柚木叶提取物作为天然染发剂的用途。这项研究是在使用煎煮法用水或乙醇-水混合物提取的年轻和成熟柚木叶上进行的。通过定量黄酮类和蒽醌含量来研究提取物中的有色物质，并使用液相色谱-质谱（LC-MS）进行鉴定；颜色值是用 CIELab 系统测量的。评估了提取物的溶解度、稳定性和染发效果。结果表明，幼叶提取物比成熟叶提取物更红，总黄酮含量更高。百分之五十的乙醇是从柚木叶中提取高黄酮的最佳溶剂。聚山梨醇酯 20 显着增加了嫩叶和成熟叶提取物的水溶性。用嫩叶提取物染的头发变成红棕色，而用成熟叶提取物染的头发变成棕色。稳定性测试发现提取物有一些类黄酮降解，但提取物仅发生轻微的颜色变化。LC-MS 曲线显示高强度类黄酮峰，可用于控制具有其他参数的提取物的颜色质量。这些结果表明柚木叶提取物是有效的天然染发剂，可用于开发染发剂产品。