Page 141 - journal-6-2-S-Full

ÒÙ «“√ “√°“√·æ∑¬å·ºπ‰∑¬·≈–°“√·æ∑¬å∑“߇≈◊Õ° ªï∑’Ë ˆ©∫—∫∑’Ë Ú æƒ…¿“§¡- ‘ßÀ“§¡ (©∫—∫‡ √‘¡) ÚııÒ

PO-38

Phytochemical study and antibacterial activity of Punica granatum L.

leaves

Suwakon Hemmun, Noppamas Soonthornchareonnon
Department of Pharmacognosy, Faculty of Pharmacy, Mahidol University, Bangkok 10400. Thailand.

Rationale: Diarrhoeal disease is a leading cause of morbidity and mortality, especially in children in the

developing countries. From the vast array of the Materia Medica of the indigenous system, so many plants have
been reported to have activity against diarrhoea. The antibacterial screening of various plant extracts comprising in
Yaleungpidsamud recipe showed that alcoholic extracts of Quercus infectoria, Uncaria gambir, Lawsonia inermis

and Punica granatum were the active extracts. However, there has been no report on the antibacterial activity of
P. granatum leaves. So, it is valuable to isolate active compounds from P. granatum leaves and investigate
antibacterial activity.

Objective: To isolate active compounds from active fractions of P. granatum L. leaves.

Methodology: The powdered drugs of P. granatum leaves were extracted with 80% ethanol. The ethanolic extract
was further isolated by chromatographic techniques. Subfractions were tested for antibacterial activity by microdilution
assay. The active fractions were isolated and purified by column chromatography. The pure compounds were also

evaluated using the microdilution assay to determine the MBC values. Chemical structures were elucidated by
spectroscopic methods including ultraviolet spectroscopy, mass spectroscopy, infrared spectroscopy and nuclear
magnetic resonance spectroscopy. The quantitative analysis of total phenolic contents, tannins and gallic acid was

determined by Folin-Ciocalteau method, Thai Herbal Pharmacopoeia (1992) and HPLC assay.
Results: The eight fractions from ethanolic extract of P. granatum leaves showed antibacterial activity against

Staphylococcus aureus ATCC 25923, Vibrio parahaemolyticus ATCC 5665, Shigella flexneri and Bacillus cereus
ATCC 14579. Gallic acid and luteolin, which were obtained from the active fraction showed activity against
Staphylococcus aureus ATCC 25923 (0.031 and 0.037 mg/ml), Salmonella typhimurium ATCC 11331 (0.500 and
0.150 mg/ml), Vibrio parahaemolyticus ATCC 5665 (0.250 and 0.018 mg/ml), Escherichia coli ATCC 25922

(0.500 and 0.150 mg/ml), Shigella flexneri (0.031 and 0.037 mg/ml) and Bacillus cereus ATCC 14579 (0.250 and
0.075 mg/ml), respectively. The amounts of total phenolic compounds, total tannins and gallic acid were 48.40,
24.94 and 3.26% (w/w), respectively.

Conclusion: The ethanolic extract and chemical compounds, i.e., gallic acid and luteolin, exhibited antibacterial
activity against bacteria that cause diarrhea. However, the other antibacterial components of the extract will be

further investigated.