Preliminary examination of mitragynine and 7-hydroxymitragynine synthesis in response to production environment and postharvest techniques of Mitragyna speciosa
Perceived human health benefits resulting from consumption of Mitragyna spp. have led to the long history of their use as valuable ethnobotanical plants. Mitragyna speciosa, or kratom, synthesizes two pharmacologically active alkaloids, mitragynine and 7-hydroxymitragynine, within its leaves. These unique alkaloids produce analgesic, opiate-like psychoactive effects when consumed. For hundreds of years, leaves have been harvested and used to aid in relief of pain, fatigue, and to assist in overcoming drug addiction. To better understand the presence of these unique alkaloids within M. speciosa, a preliminary investigation examined the synthesis and concentration of mitragynine and 7-hydroxymitragynine in response to environmental production conditions and postharvest treatments. To examine the influence of postharvest drying and processing on alkaloids, leaves from a single large tree were collected and subjected to one of three fermentation periods (0, 90, or 180 min), one of three processing methods (none, cut, deveined), and one of four drying temperatures (25, 30, 68, or 80°C). Despite the variation in postharvest treatments, no trends in distribution of alkaloids were observed. To examine the influence of environmental production conditions on alkaloid synthesis, three M. speciosa trees cultivated in a greenhouse were moved to an outdoor growing environment and monitored for changes in alkaloid concentrations. Following a move to an area with greater light intensity, higher temperature, and fuller light spectral quality, mitragynine concentrations increasing approximately 2.5-fold within two weeks. No detection of 7-hydroxy mitragynine was observed in any plants throughout the study. Results from this preliminary examination provide a greater understanding of mitragynine concentrations and synthesis in M. speciosa and provide foundational information necessary for future research focused on indole alkaloid concentrations found within M. speciosa leaves.
Pearson, B.J., Campbell, S.M., Avery, B., McCurdy, C., Francisco, J., Sharma, A. and Kjelgren, R. (2020). Preliminary examination of mitragynine and 7-hydroxymitragynine synthesis in response to production environment and postharvest techniques of Mitragyna speciosa. Acta Hortic. 1274, 89-96
kratom, ketum, medicinally active