Chemical constituents, molecular docking, and acetylcholinestrase inhibitory activity of Macaranga gigantea

Genus Macaranga comes from the family of Euphorbiaceae and known for their mutual associations with ants. Fresh or dried leaves of some Macaranga species was used by traditional healers to treat swellings, cuts, sores, boils and bruises. The isolation of chemical constituents from this genus have produced phenolic compounds, such as flavonoids and stilbenoids [1], [2]. Phytochemical study was done on Macaranga gigantea, known as Mahang gajah. The purpose of this study was to isolate the chemical constituents from the leaves of Macaranga gigantea, to evaluate the anti-acetylcholinesterase property, and to discuss the binding conformation of the isolated compound with the enzyme, using molecular docking. Several chromatography techniques such as vacuum liquid, radial, column, and preparative thin layer chromatographies were used to isolate of the pure compounds. The structure of the isolated compound was confirmed by means of spectroscopy methods such as infrared (IR), ultraviolet-visible (UV-Vis), nuclear magnetic resonance (NMR), mass (MS) spectroscopy and by comparison with the literature data. Two flavonoids were successfully isolated from the leaves of Macaranga gigantea, which are glyasperin A and apigenin [3], [4]. The molecular docking study showed that both glyasperin A [Fig. 1] and apigenin [Fig. 2] are situated in a peripheral anionic site surrounded Trp86, Tyr124, Trp286, Leu289, Arg296, Ile294, Tyr337, Tyr341, and Ile451 which suggested that both compounds can potentially block the entrance of the active site gorge, thus prevent the ACh bind to the AChE [5]. This result is further supported by the percent inhibition at 100 µM of the two compounds.

Fig. 1 Binding interaction of glyasperin A in active site gorge of AChE

Fig. 2 Binding interaction of aplgenis in active site gorge of AChE

• References

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