Isolation, Synthesis and AC hE Inhibitory Potential of Some Novel Cinnamyl Esters of Taraxerol, the Major Metabolite of the Mangrove Bruguiera cylindrica

Systematic chemical screening of the leaves of Bruguiera cylindrica, the tree mangrove of Rhizophoraceae family, afforded five single and pure compounds. The structures of the isolated compounds were established by their spectroscopic data as taraxerol (1), 3β‐(E)‐coumaroyltaraxerol (2), 3β‐(Z)‐coumaroyltaraxerol (3), β‐sitosterol (4), and eicosanol (5). In view of significant accumulation and interesting biological activities, taraxerol (1) was chemically transformed to synthesize a series of ten cinnamyl esters in very good to excellent yields. The synthesized analogues along with the parent compound were evaluated for their AChE inhibitory potential, BBB permeability and cytotoxicity against Neuro 2A cell line. Among the tested samples, compound 9 showed promising AChE inhibition with significantly low IC50 values, low cytotoxicity and high BBB permeability. Hence, compound 9 can be considered as a lead molecule for further development as potent AChE inhibitor.