Alkaloids from Erythrina crista-galli flowers and their inhibitory activities against acetylcholinesterase: in vitro and in silico studies

Acetylcholinesterase (AChE) is a hydrolytic enzyme that breaks down acetylcholine into choline and acetate. In patients with Alzheimer’s disease, the increased AChE activity may contribute to early degeneration of cholinergic neurons in the basal forebrain, resulting in impaired cholinergic signalling. This study aims to evaluate the anticholinesterase activity of alkaloids isolated from Erythrina crista-galli flowers through an integrated approach combining in vitro and in silico studies.

Four alkaloids, namely cristamidine (1), erythrinine (2), erythraline (3), and 8-oxoerythrinine (4), were isolated and their structures were confirmed through high-resolution mass spectrometry (HR-MS) and nuclear magnetic resonance (NMR). In vitro assay conducted at a concentration of 50 µg/mL showed that cristamidine has the highest inhibition effect, followed by 8-oxoerythrinine, erythrinine, and erythraline. In silico studies comprising molecular docking and molecular dynamics simulations showed that both cristamidine and 8-oxoerythrinine formed stable interactions with the active pocket of AChE.

This study highlights the potential of E. crista-galli as a natural source of AChE Inhibitors. This publication charge is funded by Unpad through the Indonesian Endowment Fund for Education (LPDP) on behalf of the Indonesian Ministry of Higher Education, Science and Technology and managed under the EQUITY program. The authors gratefully acknowledge the support provided by the National Research and Innovation Agency for the NMR measurement.

The authors are grateful for funding from Hibah Internal Universitas Padjadjaran (No. 5940/UN6.D/PT/2026) by Euis Julaeha. Department of Chemistry, Faculty of Mathematics and Natural Science, Padjadjaran University, Jatinangor, Sumedang, West Java, 45363, Indonesia Tati Herlina, Ari Hardianto, Tri Mayanti & Euis Julaeha Research Center for Food Technology and Processing, National Research and Innovation Agency, Yogyakarta, 55861, Indonesia Abd. Wahid Rizaldi Akili & Sri Handayani Research Centre for Pharmaceutical Ingredients and Traditional Medicine, National Research and Innovation Agency (BRIN), Jl.

Raya Jakarta Bogor Km 46, Cibinong, West Java, 16911, Indonesia Department of Chemical Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia (UKM), 46300, Bangi, Selangor, Malaysia The authors declare no competing interests. Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made.

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