Two new pyrrolidine alkaloids, broussonetines K and L, were isolated from the branches of Broussonetia kazinoki SIEB. (Moraceae). Broussonetines K and L were formulated as (2R,3R,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-[(1R)-1-hydroxy-10-oxo-13-(β-p-glucopyranosyloxy) tridecyll pyrrolidine (1) and (2R,3R,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-[(1R)-1-hydroxy-9-oxo-13-(β-D-glucopyranosyloxy) tridecyll pyrrolidine (2), respectively, by spectroscopic and chemical methods. 1 and 2 inhibited β-glucosidase, β-galactosidase and β-mannosidase.