An antifungal protein, possessing a molecular weight of 28 kDa and an N-terminal sequence resembling chitinases, has been purified from the seeds of the field bean Dolichos lablab. The procedure involved extraction with aqueous buffer, affinity chromatography on Affi-gel blue gel, and ion exchange chromatography on CM-Sepharose. The protein, designated dolichin, exhibited antifungal activity against the fungi Fusarium oxysporum, Rhizoctonia solani, and Coprinus comatus. Dolichin was capable of inhibiting human immunodeficiency virus (HIV) reverse transcriptase and alpha- and beta-glucosidases which are glycohydrolases implicated in HIV infection. It had very low ribonuclease and cell-free translation-inhibitory activities.