Definition: Apocinchonine: A compound found in plants known as Apocynaceae, consisting of two chains of C4 carbon units. It's also called a "C-13" compound due to its structure resembling that of 13C atoms. This element plays a crucial role in plant physiology and chemistry by aiding in the synthesis of certain amino acids, which are essential for many functions within the body. Definition: Apocinchonine is a naturally occurring compound found in plants like those known as Apocynaceae. It consists of two chains of C4 carbon units that resemble 13C atoms, making it an "C-13" compound. This property aids in the synthesis of certain amino acids crucial for various bodily processes.