Human Sebaceous <i>Cis</i>-6-Hexadecenoic Acid: Possible Application of an Innate Antimicrobial Substance to Cosmetic Products for Mucous Membrane

The antimicrobial properties of cis-6-hexadecenoic acid (C16:1Δ6), a component of the innate human metabolome, were studied and its application to cosmetic products was investigated in detail. A variety of the resident and transient microbial flora of the skin, oral cavity, and intestine was applied to an investigation of the antimicrobial activity of C16:1Δ6. C16:1Δ6 showed selective antibacterial activity against human microbial pathogens such as Clostridium perfringens (one of the most common causes of food poisoning) and Streptococcus mutans (one of the tooth-decaying bacteria), as well as Staphylococcus aureus. C16:1Δ6 seemed to possess a “species-selective” antibacterial activity against bacteria belonging to the genera Staphylococcus and Clostridium. We performed a preliminary assessment of the application of C16:1Δ6 as an antimicrobial component in a liquid lip gloss by performing preservation efficacy and home-use tests. We noted that the amount of p-hydroxybenzoate was needed in an oily cosmetic, especially liquid lip gloss, could be reduced by replacing p-hydroxybenzoate with C16:1Δ6. We suggest that C16:1Δ6 may find application as a stable antimicrobial substance gentle enough for use in consumer products by its selective antimicrobial characteristics.

同时测定唇彩中苏丹红Ⅰ和Ⅱ的高效液相色谱法的建立

目的建立准确、灵敏的高效液相色谱法同时测定唇彩中苏丹红Ⅰ和苏丹红Ⅱ的分析方法。方法样品经乙腈-甲醇-氯仿(体积比为2∶1∶1)混合溶剂提取后,在C18色谱柱上,以0.1%乙酸溶液和含0.1%乙酸的乙腈溶液作为流动相,采用梯度洗脱分离,在476 nm波长进行检测。结果苏丹红Ⅰ和苏丹红Ⅱ的加标回收率在86.2%～106.2%范围,其相对标准偏差均小于5.0%,在0.2～20.0 mg/L范围呈现良好的线性关系,其回归系数大于0.999,检出限(LOD)分别为0.02和0.03 mg/kg,最低定量检出限(LOQ)分别为0.07和0.10 mg/kg。结论本方法简便、灵敏、重现性好,能满足唇彩中苏丹红Ⅰ和Ⅱ残留的监测要求。