Xenin-8, a C-terminal octapeptide, is a biologically active fragment of Xenin. Xenin is a 25-amino acid peptide of the neurotensin/xenopsin family. Xenin-8 stimulates basal insulin secretion and potentiates the insulin response to glucose in a dose-dependent manner (EC50=0.16 nM).

Guaiacylglycerol-beta-guaiacyl Ether is degraded by microorganisms and is commonly used as a substrate to mimic microbial degradation of cell walls of lignin-living plants.

(D-Leu2)-Melanocyte-Stimulating Hormone-Release Inhibiting Factor