Hupehenine is a steriodal alkaloid extracted from the bulbs of Fritillaria Hupehensis, with the potential for inhibiting acetylcholine, antagonism for muscarinic receptors and cholinesterase inhibition.

Potent, endogenous neuromedin U receptor agonist (EC50 values are 65 and 91 pM at NMU1 and NMU2 respectively). Induces phase shifts in the circadian rhythm of locomotor activity following i.c.v. administration. Potent endogenous anorexigenic peptide.

Pyridoxal 5′-phosphate the active form of vitamin B6 is a cofactor for many different enzymes involved in transamination reactions including mitochondrial cysteine desulfurase cystathionine γ-synthase various aminotransferases and a d-serine dehydratase.