Synthesis Of Aloe Chromones And Their Derivatives

The use of cosmetics has a very long history,and it has spread to the present with the existence and development of human beings.Fair and moisturizing skin is the pursuit of oriental women,so Asia Pacific area is the world's largest consumer market for whitening skin care products.Studies have confirmed that aloe chromones(mainly aloesone and its derivatives)isolated from natural aloe have whitening,antioxidant,sunscreen and anti-aging effects in the skin beauty and health.However,the content of aloe chromone in aloe is very low,separation is difficult,and the cost of purification is too high,which limits the application of aloe chromone as a raw material in the field of cosmetics.We found that aloesone is not very stable in earlier research.If the derivatives of aloesone can be fully synthesized,new compounds with higher activity and better stability may be found.Providing a high-quality and cheap raw material for the cosmetics market is of great significance to the cosmetics industry.Therefore,this paper designed and synthesized the derivatives of aloesone for the 2-C and 3-C positions of aloesone,respectively.Using 3,5-dihydroxytoluene as raw material,two series of 15 aloesone derivatives were synthesized and their biological activities were measured respectively.1.Synthesis of aloesone 2-C modified derivatives.Through acylation reaction,esterification reaction,substitution reaction,etc.,five compounds substituted with different groups at 2-C position were synthesized,one of which was a new compound.The results of tyrosinase inhibitory activity showed that the IC50 of the synthetic derivatives were between 2.4-9.6 ?M(Aloe pine was 2.4 ?M).After replacing the acetone group with an alkyl group at the 2-C position,the activity is not greatly affected,but the stability of the compound is increased.2.Synthesis of aloesone modified at the 3-C position.Also through the acylation reaction,esterification reaction,substitution reaction and so on,10 compounds substituted with different groups at the 3-C position were synthesized,6 of which were new compounds.The DPPH method was used to test the antioxidant activity of the synthetic compounds.The EC50 were between 1.8-66.5 m M(ascorbic acid was0.08 m M).The stability of derivatives is improved,some compounds have certain free radical scavenging activity,but the activity is generally lower than ascorbic acid.