Screening and characterization of antiviral compounds from Psidium guajava Linn. root bark against white spot syndrome virus

White Spot Syndrome Virus (WSSV) has been reported to cause severe mortality and economic loss in shrimp culture industry especially black tiger shrimp in worldwide. In present study, Psidium guajava Linn. root bark was serially extracted with hexane, ethyl acetate and methanol then screened antiviral activity against WSSV by incubating the extracts with WSSV infected haemolymph of Penaeus monodon which was propagated earlier. The incubated haemolymph was intramuscularly injected to the second abdominal segment of Indian white shrimp Fennerropenaeus indicus and monitored the survival up to 10 days. Two step PCR detection was performed from the genomic DNA of treated shrimps using VP 28WSSV diagnostic PCR primer. The survival and two step PCR detections revealed that, the ethyl acetate extract effectively suppressed the WSSV followed by methanol extracts and no antiviral activity was observed in the hexane extracts. Phytochemical analysis was performed with the active extracts and further this was purified through silica column chromatography and Thin Layer Chromatography. The elution was screened again for anti-WSSV activity and the antiviral active elution of P. guajava were analysed by GC-MS which revealed that the active elution contains active compounds such as phenol, 2,5-bis(1,1-dimethylethyl), diethyl phthalate, asarone, phthalic acid, butyldodecyl ester, phytol and 1,2-benzenedicarboxylic acid, mono(2-ethylhexyl) ester. The present study revealed that there is a possibility for developing new antiviral drugs from P. guajava against WSSV infection.