Leguminous　plants　have　formed　a　popular　subject　of　research　owing　to　the　abundance　of　proteins　and　peptides　with　important　biological　activities　that　they　produce.　The　antifungal　proteins　and　peptides　have　been　purified　from　a　number　of　leguminous　species.　However,　research　continues　to　discover　novel　antifungal　plant-produced　peptides　and　proteins　are　being　needed,　specially　those　novel　ones　with　both　antifungal　activity　and　other　significant　bioactivities.　The　objective　of　this　study　was　to　isolate　a　novel　peptide　from　Phaseolus　limensis.　A　6.8　kDa　peptide　designated　Limyin,　with　both　antifungal　and　antiproliferative　activity,　was　isolated　from　the　large　lima　bean　(P.　limensis)　legumes.　The　isolation　procedure　consisted　of　extraction,　precipitation,　affinity　chromatography　on　Affi-gel　blue　gel,　ion　chromatography　on　SP-Toyopearl,　and　gel　filtration　on　Superdex　75.　Its　N-terminal　sequence　was　determined　to　be　KTCENLATYYRGPCF,　showing　high　homology　to　defensin　and　defensin　precursors　from　plants.　It　potently　suppressed　mycelial　growth　in　Alternaria　alternata,　Fusarium　solani,　and　Botrytis　cinerea.　Its　antifungal　activity　was　stable　up　to　80°C.　It　showed　antiproliferative　activity　towards　tumor　cells　including　human　liver　hepatoma　cells　Bel-7402　and　neuroblastoma　cells　SHSY5Y.　However,　it　had　no　effect　on　bacteria　Staphylococcus　aureus　and　Salmonella.　The　present　findings　make　a　significant　addition　of　the　research　on　leguminous　plants.　©　2008　Springer-Verlag.