CC BY-NC-ND 4.0 · Planta Med 2022; 88(09/10): 838-857
DOI: 10.1055/a-1795-5876
Natural Product Chemistry and Analytical Studies
Original Papers

Kratom (Mitragyna speciosa) Validation: Quantitative Analysis of Indole and Oxindole Alkaloids Reveals Chemotypes of Plants and Products[ # ]

Preston K. Manwill
Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, USA
Laura Flores-Bocanegra
Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, USA
Manead Khin
Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, USA
Huzefa A. Raja
Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, USA
Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, USA
Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, USA
Daniel A. Todd
Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, USA
› Author Affiliations
Supported by: National Center for Complementary and Integrative Health U54 AT008909


Many consumers are turning to kratom (Mitragyna speciosa) to self-manage pain and opioid addiction. In the United States, an array of capsules, powders, and loose-leaf kratom products are readily available. Additionally, several online sites supply live kratom plants. A prerequisite to establishing quality control and quality assurance standards for the kratom industry, or understanding how alkaloid levels effect clinical outcomes, is the identification and quantitation of major and minor alkaloid constituents within available products and preparations. To this end, an ultra-high performance liquid chromatography-high resolution mass spectrometry method was developed for the analysis of 8 indole alkaloids (7-hydroxymitragynine, ajmalicine, paynantheine, mitragynine, speciogynine, isopaynantheine, speciociliatine, and mitraciliatine) and 6 oxindole alkaloids (isomitraphylline, isospeciofoleine, speciofoline, corynoxine A, corynoxeine, and rhynchophylline) in US-grown kratom plants and commercial products. These commercial products shared a qualitatively similar alkaloid profile, with 12 – 13 detected alkaloids and high levels of the indole alkaloid mitragynine (13.9 ± 1.1 – 270 ± 24 mg/g). The levels of the other major alkaloids (paynantheine, speciociliatine, speciogynine, mitraciliatine, and isopaynantheine) and the minor alkaloids varied in concentration from product to product. The alkaloid profile of US-grown M. speciosa “Rifat” showed high levels of the indole alkaloid speciogynine (7.94 ± 0.83 – 11.55 ± 0.18 mg/g) and quantifiable levels of isomitraphylline (0.943 ± 0.033 – 1.47 ± 0.18 mg/g). Notably, the alkaloid profile of a US-grown M. speciosa seedling was comparable to the commercial products with a high level of mitragynine (15.01 ± 0.20 mg/g). This work suggests that there are several M. speciosa chemotypes.

# Dedicated to Professor Dr. A. Douglas Kinghorn on the occasion of his 75th birthday.

Supporting Information

Publication History

Received: 08 October 2021

Accepted after revision: 23 February 2022

Article published online:
25 April 2022

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