Department of Pharmaceutical Sciences, Faculty of Science, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa.
Phytochemistry. 2013 Dec;96:15-25. doi: 10.1016/j.phytochem.2013.08.005. Epub 2013 Sep 17.
Menthol is a cyclic monoterpene alcohol which possesses well-known cooling characteristics and a residual minty smell of the oil remnants from which it was obtained. Because of these attributes it is one of the most important flavouring additives besides vanilla and citrus. Due to this reason it is used in a variety of consumer products ranging from confections such as chocolate and chewing gum to oral-care products such as toothpaste as well as in over-the-counter medicinal products for its cooling and biological effects. Its cooling effects are not exclusive to medicinal use. Approximately one quarter of the cigarettes on the market contain menthol and small amounts of menthol are even included in non-mentholated cigarettes. Natural menthol is isolated exclusively from Mentha canadensis, but can also be synthesised on industrial scale through various processes. Although menthol exists in eight stereoisomeric forms, (-)-menthol from the natural source and synthesised menthol with the same structure is the most preferred isomer. The demand for menthol is high and it was previously estimated that the worldwide use of menthol was 30-32,000 metric tonnes per annum. Menthol is not a predominant compound of the essential oils as it can only be found as a constituent of a limited number of aromatic plants. These plants are known to exhibit biological activity in vitro and in vivo such as antibacterial, antifungal, antipruritic, anticancer and analgesic effects, and are also an effective fumigant. In addition, menthol is one of the most effective terpenes used to enhance the dermal penetration of pharmaceuticals. This review summarises the chemical and biological properties of menthol and highlights its cooling effects and toxicity.
薄荷醇是一种环状单萜醇，具有众所周知的清凉特性和其来源油残余物的薄荷气味。由于这些特性，它是除香草和柑橘之外最重要的调味添加剂之一。由于这个原因，它被用于各种消费品，从巧克力和口香糖等糖果到牙膏等口腔护理产品，以及用于其冷却和生物效应的非处方药。它的冷却效果不仅限于药用。市场上大约四分之一的香烟含有薄荷醇，即使在非薄荷醇香烟中也含有少量薄荷醇。天然薄荷醇仅从薄荷中分离出来，但也可以通过各种工艺在工业规模上合成。尽管薄荷醇存在八种立体异构体，但来自天然来源的 (-)-薄荷醇和具有相同结构的合成薄荷醇是最优选的异构体。对薄荷醇的需求很高，据此前估计，全球每年使用的薄荷醇为 30,000-32,000 公吨。薄荷醇不是精油的主要化合物，因为它只能作为有限数量芳香植物的成分存在。这些植物已知在体外和体内具有生物活性，如抗菌、抗真菌、止痒、抗癌和镇痛作用，并且也是有效的熏蒸剂。此外，薄荷醇是用于增强药物透皮吸收的最有效萜烯之一。本综述总结了薄荷醇的化学和生物学特性，并强调了其冷却效果和毒性。
