Glyceridic esters of p-methoxycinnamic acid. A new sunscreen of the cinnamate class

The aim of this work was to investigate whether a 1,3-diacylglycerol moiety can act as enhancer of the photoprotecting action of a new sunscreen of the cinnamate class, owing to its affinity with skin constituents and lower susceptibility to hydrolysis at C-2. The sun protection factors (SPF) for 1,2,3-propanetriol 1,3-dipalmitate-2-p-methoxycinnamate and 1,2,3-propanetriol 1,3-dioctanoate-2-p-methoxy-cinnamate (2.0, 4.5 and 7.5%) were determined. The sunscreen preparations presented SPF values between 4.7 and 16. The results show that although glyceridic esters present higher lipophilicity and are more stable towards enzymatic hydrolysis in vitro, the synthesized triacylglycerols and the standard sunscreen 2-ethylhexyl p-methoxycinnamoyl (EHPM) showed equivalent SPF values for both methods.