GnRH-I is a small 10 amino acid long peptide (decapeptide) from the hypothalamus,It is also known as luteinizing hormone releasing hormone (LHRH), is a key molecule in the regulation of reproduction in vertebrates. GnRH, a decapeptide, is produced by neurons in the medial basal hypothalamus (MBH) and secreted in a pulsatile manner into the cardiovascular system.

Ethotoin (Peganone), an orally active anticonvulsant agent utilized in epilepsy research, is a hydantoin derivative analogous to phenytoin .

3-羟基丁酸参与酮体的合成和降解。与其他酮体（乙酰乙酸和丙酮）一样，酮症中血液和尿液中的β-羟基丁酸水平升高。 β-羟基丁酸是肌肉释放用于肝和肾糖异生的支链氨基酸（主要是缬氨酸）的典型部分降解产物。