Occurrence and some properties of a virus inhibitors extracted from legume seeds

Seed extracts from 18 species of the family Leguminosae were tested for inhibitory activity against tobacco necrosis virus [TNV] onto Phaseolus vulgaris L. Aqueous crude seed extracts of all the species were inhibitory to virus infection but to varying degrees. Twelve out of 18 examined species showed potent inhibition [80 - 98%]. The inhibitory activity of the majority of species was decreased on dilution [1: 1000] suggesting that they act as virus inhibitors and not inactivators. Further dilution of the extracts of a few species revealed the presence of an inhibitor which decreased and an augmenter which increased the number of lesions. The heated seed extracts fall into four categories: Those which are thermolabile inhibitors, those which are thermostable inhibitors, those which are thermostable augementers and those which inhibitory activity increased by heating. Ethanol treatment indicated that the inhibitors of all tested extracts were composed, at least in part, of proteins or glycoproteins

Mode of action of tobacco necrosis virus inhibitors extracted from seeds of enterolobium cyclocarpum and phaseolus vulgaris

Aqueous seed extracts prepared from two species belonging to the family Leguminosae [Enterolobium cyclocarpum Griseb and Phaseolus vulgaris L] were inhibited local lesion production by tobacco necrosis virus [TNV]. Dilution of both extracts confirmed the presence of plant virus inhibitors and not inactivators. Inhibition was slightly decreased by heating E. Cyclocarpum seed extracts, while the inhibitory activity of P. Vulgaris seed extracts was increased by heating. The virus inhibitors from both extracts had no direct effect on the virus. The virus inhibitors from both extracts had no direct effect on the virus. They seem either to affect the attachment of the virus to the infective sites or perhaps allow attachment but prevent entry of virus into the cell