Chemical, pharmacological properties and biosynthesis of opioid mitragynine in Mitragyna speciosa (kratom)

Mitragynine, an alkaloid found in Mitragyna speciosa (kratom), shows promise as a potential alternative to opioids owing to its distinctive indole alkaloid structure and its capacity for pain relief, alleviation of opioid withdrawal symptoms, and anti-inflammatory effects. Recently the intricate process of mitragynine biosynthesis from the precursor strictosidine was elucidated, providing insights into the complex pathways responsible for synthesizing this opioid compound and its related diastereomers. As the search continues for the authentic hydroxylase and methyltransferase crucial for mitragynine formation, leveraging enzymes from other species and exploiting enzyme promiscuity has facilitated heterologous mitragynine biosynthesis in microbes. This highlights the extraordinary flexibility of enzymes in generating a spectrum of variations and analogs of kratom opioids within alternative biological systems.