Bioactive compounds from endophytic fungi isolated from Piper betle Linn.

Abstract

The purpose of this research was to isolate bioactive compounds from endophytic fungi isolated from Thai medicinal plant Piper betle Linn. Leaves samples were collected from Bangkok, Pathumthani, Rayong and Nakornsithammarat Province and 32 isolates of the endophytic fungi were obtain by surface sterilization technique and placed onto potato dextrose agar. Fungal endophytes were isolated from leaves. Thirty two fungal isolates were tested for the production of antimicrobial compounds. Fungal isolate PBL004 was chosen for the further study of bioactive compounds due to this isolate produced active compounds against Bacillus subtilis ATCC 6633, Cacdida albican ATCC 10231 and Escherichia coli ATCC 25922. Based on morphology and nucleotide sequencing of internal transcribed spacer regions of rDNA, isolate PBL004 was identified as Fusarium proliferatum . Chromatographic techniques and crystallization were used to purify bioactive compounds from malt czapekculture broth of isolate PBL004. Structure elucidation of the pure compound was investigated using physical properties and spectroscopic techniques. Mixture CB1 were isolated from broth extracts. Mixture CB1, major structure was identified as 7-butyl-6,8-dihydroxy-3(R)-pent-11-enylisochroman -1-one, which was a round white solid (melting point 158 159 degree celcius). Antimicrobial activities from this compound were tested. It was found that active against Bacillus subtilis ATCC 6633, Candida albicans ATCC 10231 with MIC 3.81 and 1000 microgram/ml, respectively and Herpes simplex virus type I ATCC VR-260 with IC[subscript 50] 6.25 microgram/ml and activity on cytotoxicity against to tumer cells; HEP-G2, SW620, KATO-3 and BT474 with IC[subscript 50] 6.8, 5.5, 7.4 and 6.8 microgram/ml, respectively. Diglyceride (1001.4 mg/ml) were isolated from mycelium extracts. These driglyceride consists of five fatty acid, myristic acid (0.40%), palmitic acid (27.21%), stearic acid (16.42%), oleic acid (37.49%) and linoleic acid (17.26%) with weight value of 4.0, 272.5, 164.4, 375.4 and 172.8 mg/L culture broth, respectively.