Project's information

Project's title Isolation and determination of the effects of antimicrobial compounds that cause food poisoning from betel nut (Piper betle L), black pepper genus
Project’s code GUST.STS.ĐT2020-SH09
Research hosting institution Graduate University of Science and Technology
Project leader’s name Le Thị Thu Hang
Project duration 01/09/2020 - 30/09/2022
Project’s budget 408 million VND
Classify Excellent
Goal and objectives of the project

To evaluate antimicrobial activity and isolate chemical compounds from Piper betle L for fighting with bacterial foodborne diseases and food poisoning.

Main results

The antimicrobial activity of four solvent extracts (methanol, ethanol, aceton and ethyl acetate) of Piper belte L against nine microbes (S. aureus, L. monocytogenes, E. faecalis, E. coli, P. aeruginosa, K. pneumoniae, S. enterica serovar Typhimurium, S. flexneri and C. Abricans) was evaluated, in which the highest antimicrobial activity was on E. coli, S. aureus, E. fecalis and C. Abricans (inhibition zones of 15 – 27 mm);
The minimum inhibitory concentrations (MIC) of solvent extracts of P. belte were determined for the nine microbes tested (MICs = 40 – 100 mg/ml), in which the methanol extract showed highest antimicrobial activity towards E. coli, S. aureus and C. albicans (MIC = 40 mg/ml). These results suggest that the P. belte extracts possesed board antimicrobial activity and effectively against Gram + bac;  
10 chemical compounds were isolated and their structures were eluciated, among them, piperbetamide A, piperbetamide B, piperbetamide C and piperbetamide D were reported for the first time, along with the six known compounds including 3,4-dihydroxyallylbenzene, 3-O-β-D-glucopyranosyl-4-hydroxyallylbenzene, 3-O-β-D-glucopyranosyl-4-methoxyallylbenzene, 4-O-β-D-glucopyranosyl-3-hydroxyallylbenzene; 4-O-β-D-glucopyranosyl-3-methoxyallylbenzene and 3,4-di-O-β-D-glucopyranosylallylbenzene.
All the 10 purified compounds had board antimicrobial activity and effectively against multidrug-resistant bacteria, with the MIC ranged from 16 to 256 µg/ml. Notably, 3,4-di-O-β-D-glucopyranosylallylbenzene exhibited strong antimicrobial activity towards on  L. monocytogenes,   methicilin-resistant S. aureus and vancomycin-resistant E. faecalis with the MIC of 16 µg/ml. Compounds  piperbetamide C and piperbetamide D had the strongest activity against only methicilin-resistant S. aureus (MIC = 16 µg/ml). Piperbetamide A, piperbetamide C, piperbetamide D, 3-O-β-D-glucopyranosyl-4-hydroxyallylbenzene and 3,4-di-O-β-D-glucopyranosylallylbenzene showed moderate antimicrobial activity against S. flexneri (MIC = 32 µg/ml).

Novelty and actuality and scientific meaningfulness of the results

Four new compounds including piperbetamide A, piperbetamide B, piperbetamide C and piperbetamide D were isolated for the first time from P. Belte of Vietnam. 

Products of the project

- Scientific papers in referred journals (list): 
Hang, L. T. T., Huy, N. Q., Tam, T. T. T., Huong, L. T., Nam, P. H., Dang, N. H., Quyet-Tien, P., Trang, D. T., Yang, S. Y. Tai, B. H. (2022). Four new N-phenethylbenzamide derivatives from the stems of piper betle and their antimicrobial activity. Nat Prod Res. Pages 1 – 9. DOI: 10.1080/14786419.2022.2114473.

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