Two new C19-diterpenoid alkaloids from Aconitum straminiflorum

The diterpenoid alkaloids

The diterpenoid alkaloids are a family of extremely important natural products that have long been a research hotspot due to their myriad of intricate structures and diverse biological properties. This chapter systematically summarizes the past 11 years (2009-2019) of studies on the diterpenoid alkaloids, including the "so-called" atypical ones, covering the classification and biogenetic relationships, phytochemistry together with 444 new alkaloids covering 32 novel skeletons and the corrected structures, chemical reactions including conversion toward toxoids, synthetic studies, as well as biological activities. It should be noted that the synthetic studies, especially the total syntheses of various diterpenoid alkaloids, are for the first time reviewed in this treatise. This chapter, in combination with our four previous reviews in volumes 42, 59, 67, and 69, will present to the readers a more completed and updated profile of the diterpenoid alkaloids.

Structural diversity, bioactivities, and biosynthesis of natural diterpenoid alkaloids

Covering: 2009 to 2018. Diterpenoid alkaloids, originating from the amination of natural tetracyclic diterpenes, are a diverse class of compounds having complex structural features with many stereocenters. The important pharmacological activities and structural complexity of the diterpenoid alkaloids have long interested scientists due to their medicinal uses, infamous toxicity, and unique biosynthesis. Since 2009, 373 diterpenoid alkaloids, assigned to 46 skeletons, have been isolated and identified from plants mostly in the Ranunculaceae family. The names, classes, molecular weight, molecular formula, NMR data, and plant sources of these diterpene alkaloids are collated here. This review will be a detailed update of the naturally occurring diterpene alkaloids reported from the plant kingdom from 2009-2018, providing an in-depth discussion of their diversity, biological activities, pharmacokinetics, toxicity, application, evolution, and biosynthesis.

Aconitum Diterpenoid Alkaloid Profiling to Distinguish between the Official Traditional Chinese Medicine (TCM) Fuzi and Adulterant Species Using LC-qToF-MS with Chemometrics

The lateral roots of Aconitum carmichaelii, known in Chinese as fuzi, are officially recognized as a materia medica in the Chinese Pharmacopoeia and used culinarily to prepare herbal soups. A strategy combining UPLC-qToF-MS analysis of A. carmichaelii and its intraspecies and interspecies chemometrics study was developed to examine the distribution of Aconitum marker metabolites. Four diterpenoid alkaloids were recognized to be important markers in fuzi, and another 15 markers were identified to differentiate A. carmichaelii from adulterant species. The detected fuzi markers, mesaconitine (47) and hypaconitine (51), are known to be the principal toxins in this herb, while fuziline (6) and benzoylmesaconine (25) are associated with its medicinal properties. Additional marker compounds have been detected in other Aconitum species that are useful for identifying adulteration. This study provides a useful resource for detecting traditional Chinese medicine (TCM) adulterants and assisting in the quality control of botanical products in TCM and beyond.

Four new C19-diterpenoid alkaloids from Aconitum hemsleyanum var. circinatum

Four new C19-diterpenoid alkaloids, hemaconitines A-D (1-4), were isolated from the roots of Aconitum hemsleyanum var. circinatum. Their structures were elucidated as 19R-hydroxyl-secoyunnaconitine (1), (3R)-hydroxyl-liwaconitine (2), 14-anisoyl-leucanthumsine E (3), and 19R -acetonyl-8-O-methyltalatisamine (4) by extensive spectroscopic analysis (IR, UV, HR-ESI-MS, 1D, and 2D NMR).