The Collaborative International Dictionary of English v.0.48:

Lupulin \Lu"pu*lin\, n. [Cf. F. lupulin. See Lupuline.]
   1. (Chem.) A bitter principle extracted from hops.
      [1913 Webster]

   2. The fine yellow resinous powder found upon the strobiles
      or fruit of hops, and containing this bitter principle.
      [Written also lupuline.]
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Lupuline \Lu"pu*line\, n. [NL. lupulus the hop, fr. L. lupus the
   hop: cf. F. lupuline.] (Chem.)
   An alkaloid extracted from hops as a colorless volatile
   liquid.
   [1913 Webster]