Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 5 4 2013 12 15 428 433 EN Darab Yazdani Pharmacognosy & Pharmaceutic Department of Medicinal Plants Research Center, Institute of Medicinal Plants-ACECR, Karaj, Iran AND Department of Plant Protection, Faculty of Agriculture, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia. Zainal-Abidin Mior-Ahmad Department of Plant Protection, Faculty of Agriculture, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia. Tan Yee How Department of Plant Protection, Faculty of Agriculture, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia. Indu Bala Jaganath Biotechnology Research Centre, Malaysian Agricultural Research and Development Institute, 50774 Kuala Lumpur, Malaysia. Sahar Shahnazi Institute of Tropical Agriculture, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. 2015 10 16 Background and Objectives: Food contamination by aflatoxins is an important food safety concern for agricultural products. In order to identify and develop novel antifungal agents, several plant extracts and isolated compounds have been evaluated for their bioactivities. Anti-infectious activity of Piper betle used in traditional medicine of Malaysia has been reported previously. Materials and Methods: Crude methanol extract from P. betel powdered leaves was partitioned between chloroform and water. The fractions were tested against A. flavus UPMC 89, a strong aflatoxin producing strain. Inhibition of mycelial growth and aflatoxin biosynthesis were tested by disk diffusion and macrodillution techniques respectively. The presence of aflatoxin was determined by thin-layer chromatography (TLC) and fluorescence spectroscopy techniques using AFB1 standard. The chloroform soluble compounds were identified using HPLC-Tandem mass spectrometry technique. Results: The results, evaluated by measuring the mycelial growth and quantification of aflatoxin B1(AFLB1) production in broth medium revealed that chloroform soluble compounds extract from P. betle dried leaves was able to block the aflatoxin biosynthesis  pathway at concentration of 500µg/ml without a significant effect on mycelium growth. In analyzing of this effective fractions using HPLC-MS2 with ESI ionization technique, 11 phenolic compounds were identified. Conclusion: The results showed that the certain phenolic compounds are able to decline the aflatoxin production in A. flavus with no significant effect on the fungus mycelia growth. The result also suggested P. betle could be used as potential antitoxin product. https://ijm.tums.ac.ir/index.php/ijm/article/view/480 https://ijm.tums.ac.ir/index.php/ijm/article/download/480/256