Laforest Larissa C, Kuntz Michelle A, Kanumuri Siva Rama Raju, Mukhopadhyay Sushobhan, Sharma Abhisheak, O'Connor Sarah E, McCurdy Christopher R, Nadakuduti Satya Swathi
Plant Molecular and Cell Biology Program, University of Florida, Gainesville, Florida 32611, United States.
Department of Pharmaceutics, College of Pharmacy, University of Florida, Gainesville, Florida 32611, United States.
J Nat Prod. 2023 Apr 28;86(4):1042-1052. doi: 10.1021/acs.jnatprod.3c00092. Epub 2023 Mar 13.
The monoterpene indole alkaloid (MIA) mitragynine has garnered attention as a potential treatment for pain, opioid use disorder, and opioid withdrawal because of its combined pharmacology at opioid and adrenergic receptors in humans. This alkaloid is unique to (kratom), which accumulates over 50 MIAs and oxindole alkaloids in its leaves. Quantification of 10 targeted alkaloids from several tissue types and cultivars of revealed that mitragynine accumulation was highest in leaves, followed by stipules and stems, but was absent, along with other alkaloids, in roots. While mitragynine is the predominant alkaloid in mature leaves, juvenile leaves accumulate higher amounts of corynantheidine and speciociliatine. Interestingly, corynantheidine has an inverse relationship with mitragynine accumulation throughout leaf development. Characterization of various cultivars of indicated altered alkaloidal profiles ranging from undetectable to high levels of mitragynine. DNA barcoding and phylogenetic analysis using ribosomal sequences revealed polymorphisms leading cultivars having lower mitragynine content to group with other mitragyna species, suggesting interspecific hybridization events. Root transcriptome analysis of low- and high-mitragynine-producing cultivars indicated significant differences in gene expression and revealed allelic variation, further supporting that hybridization events may have impacted the alkaloid profile of .
单萜吲哚生物碱（MIA）帽柱木碱因其对人体阿片类和肾上腺素能受体的联合药理学作用，作为疼痛、阿片类药物使用障碍及阿片类药物戒断的一种潜在治疗方法而受到关注。这种生物碱是（ kratom）所特有的，其叶子中积累了50多种MIA和氧化吲哚生物碱。对几种组织类型和品种的10种目标生物碱进行定量分析发现，帽柱木碱在叶子中的积累量最高，其次是托叶和茎，但在根中不存在，其他生物碱也是如此。虽然帽柱木碱是成熟叶片中的主要生物碱，但幼叶中积累了更高含量的柯楠因和特异毛钩藤碱。有趣的是，在整个叶片发育过程中，柯楠因与帽柱木碱的积累呈负相关。对各种品种的表征表明，生物碱谱有所改变，从无法检测到高含量的帽柱木碱。使用核糖体序列进行的DNA条形码和系统发育分析揭示了多态性，导致帽柱木碱含量较低的品种与其他帽柱木属物种归为一组，表明存在种间杂交事件。对低帽柱木碱产量和高帽柱木碱产量品种的根转录组分析表明，基因表达存在显著差异，并揭示了等位基因变异，进一步支持杂交事件可能影响了的生物碱谱。
