Cholinesterase Inhibitory Activity and Molecular Docking Studies of Isocryptolepine-Triazole Adducts.

Due to the rising prevalence of Alzheimer's disease (AD), there is a pressing need for more effective drugs to treat or manage AD's symptoms. Studies have shown that cholinesterase inhibition can improve cognitive and behavioral symptoms associated with AD, by addressing the cholinergic deficit. Based on the recent development of cholinesterase inhibitors with indoloquinoline and triazole moiety, we rationalized that compounds with an isocryptolepine-triazole scaffold may also have the same biological targets. In this study, eighteen previously synthesized isocryptolepine-triazole compounds were assessed for their ability to inhibit acetylcholinesterase (AChE) and butyrylcholine esterase (BChE). The majority of these compounds demonstrated potent selective AChE inhibition. Furthermore, our molecular docking and molecular dynamic simulation studies reveal that the isocryptolepine and triazole moieties are important for the binding of the compounds with the periphery of the AChE's binding pocket. While reductions in molecular weights and lipophilicities may be necessary to improve their pharmacokinetic properties, this work provides valuable insights for designing future AChE inhibitors, based on the novel isocryptolepine-triazole scaffold.

Discovery of nitric oxide-inducing activities of synthetic LAM glycan motifs prepared by scalable rapid syntheses.

Enhancement of local nitric oxide (NO) concentration is important for the effectiveness of an adjuvant and for both innate and adaptive immunological responses. Currently, the information on the NO-inducing activities of lipoarabinomannan (LAM) glycan motifs on Mycobacterium tuberculosis (Mtb) is not possibly available. Thus, detailed studies on the structure-activity relationship of discrete LAM glycan motifs could provide valuable information towards the development of adjuvants and vaccines against Mtb. Using the newly-designed monomers and linker, the new rapid synthesis strategies demonstrated in this work enabled accessibilities to α(1→6)-D-mannans and α(1→5)-D-arabinans, which are the key LAM glycan motifs, with different controlled-sizes, in a scalable fashion. The glycans were evaluated for their ability to co-stimulate nitric oxide in macrophages. Only short and medium α(1→5)-D-arabinans show distinct abilities to strongly enhance LPS-induced nitric oxide, suggesting their potential use as stronger immunomodulators than α(1→6)-D-mannans, and thus, implying an unknown receptor responsible for this NO-inducing effect.