Skin aging is a gradual, spontaneous, slow-processing, and natural phenomenon that induces a neg. impact on the skin′s function and structure.Numerous cosmoceutical products have been studied for their ability to prevent skin aging.However, only one published study looked into these coumarin-related traits.This research gap stimulated the initiation of the present work, in which six 4-phenyldihydroxybenzocoumarins were synthesized starting from 2,3,6-triaminonaphthalene.The latter was transformed into a diazonium salt product that undergoes a Sandmeyer reaction, forming 2,3,6-trihydroxynaphthalene.This multihydroxylated compound is coupled with various Et benzoylacetate derivatives to yield the target compounds coded YR1-YR6.By analyzing the FTIR, 1HNMR , 13CNMR , and HRMS spectra, the mol. structures of the synthesized coumarins were confirmed.The anti-skin-aging potential was evaluated by following the inhibitory properties of these compounds against four skin aging-related enzymes, which are tyrosinase, elastase, collagenase, and hyaluronidase.Also, the inhibitory behavior profiles were defined by plotting Lineweaver-Burk diagrams.To detect whether they are normal-skin biocompatible, the compounds under investigation were tested using a human skin keratinocyte line.The results showed that the synthesized coumarins demonstrated outperforming inhibitory properties against the test four enzymes exceeding those of references used.Also, the inhibitory behaviors of the synthesized coumarins were collectively detected as competitive inhibitors against enzymes under study.Regarding the skin biocompatibility, these compounds showed excellent biosafety profiles toward the keratinocytes studied.Given the results, the general framework of the synthesized coumarins, 7,8-dihydroxy-4-phenylbenzo[g]coumarin, is responsible for the superior anti-skin-aging effects.On the other hand, the para substitution on the Ph ring exerts a detected but minor role in these effects.The author concluded that the skeletons of the synthesized coumarins provide insights to develop potential multitarget anti-skin-aging biocompatible candidates.Also, there is a good opportunity for YR1 and YR2 to be directly included in the pre-clin. studies, minimizing the time spent considering them as anti-skin medications.