Any of various nitrogen-containing organic compounds, derived from pyrrole, occurring universally in protoplasm and providing the foundation structure for hemoglobin, chlorophyll, and certain enzymes.

• 卟啉一类含氧的有机化合物的一种，由卟咯衍生而来普遍存在于细胞质中，是构成血红蛋白、呼吸色素及某些酶的基本结构