Four new resin glycosides, quamoclins I-IV, were isolated from the jalapin fraction of the seeds of Quamoclit pennata, and their structures have been determined on the basis of chemical and spectral data. They are the first examples of jalapins with organic acid (2S-methylbutyric acid) and fatty acid (n-decanoic or n-dodecanoic acid) groups coexisting in the molecules.