A systematic review on the chemical constituents of the genus Consolida (Ranunculaceae) and their biological activities

Micromorphological and phytochemical profiling of Delphinium suave Huth. from Hindukush range, Lower Dir Khyber Pakhtunkhwa Pakistan

This is a very first attempt to study various parameters of a medicinal plant, Delphinium suave Huth. The plant is erect, geophytic, herbaceous, with tuberous root, trifid in a palmatipartite, strigose cuneate leaf and white spurred zygomorphic flower. The root was isodiametric phellem with single non-glandular trichomes. The stem revealed single-layered cuticle, multiseriate epidermis, cortex, pith ray and uniserate bowed non-glandular trichomes. The leaf was amphistomatic, showed tapering trichomes, prismatic crystals and ranunculaceous stomata with circumference 144.66-182.67 μm. Pollen grains in Light Microscopy (LM), were prolate, spheroidal trizonocolpate, isopolar, radiosymmetric, scabrate, elliptic and monads. Scanning Electron Microscope (SEM) pollen surface was scabrate, monad, size varied from 18.06 to 16.67 μm, colpus to inaperturate, tricolpate, ornamented, echinus, isopolar, isodiametric and circular. SEM roots showed sclerenchymatic tissues, stellate, glandular, non-glandular trichomes and crystals. The stem showed scalariform, pitted vessels, warty protuberances, unicellular, silicified, non-glandular trichomes. Leaves powder revealed, simple, unicellular, tapered headed, uniseriate, sessile, capitate, unbranched glandular, non-glandular, trichomes with crystals. Capitate, stellate, circular, unicellular, branchy trichomes were observed for the first time through SEM. Powder drug study of root, stem leaves through LM revealed different tissues. Preliminary phytochemical revealed alkaloids, anthocyanins, anthraquinones, coumarins, flavones, mucilages, saponins, steroids, terpenoids, volatile oils and proteins. GC/MS showed 36 compounds in roots, 33 in stem while 40 in leaves. Fluorescence analysis of roots, stem and leaves showed variations in color when treated with chemicals. This study will assist pharmacognostic exploration, authentication from adulterants/allied species for consistent quality, resulting in safe use, preservation and efficacy. RESEARCH HIGHLIGHTS: This was first attempt on pharmacognostic study on D. suave Huth. which could be used as a foundation for identifying and authenticating the specie from other allied species by these morphological, anatomical, GC/MS profiling, phytochemical analysis and fluorescence analysis.

Neuropharmacological Potential of Diterpenoid Alkaloids

This study provides a narrative review of diterpenoid alkaloids (DAs), a family of extremely important natural products found predominantly in some species of Aconitum and Delphinium (Ranunculaceae). DAs have long been a focus of research attention due to their numerous intricate structures and diverse biological activities, especially in the central nervous system (CNS). These alkaloids originate through the amination reaction of tetra or pentacyclic diterpenoids, which are classified into three categories and 46 types based on the number of carbon atoms in the backbone structure and structural differences. The main chemical characteristics of DAs are their heterocyclic systems containing β-aminoethanol, methylamine, or ethylamine functionality. Although the role of tertiary nitrogen in ring A and the polycyclic complex structure are of great importance in drug-receptor affinity, in silico studies have emphasized the role of certain sidechains in C13, C14, and C8. DAs showed antiepileptic effects in preclinical studies mostly through Na⁺ channels. Aconitine (1) and 3-acetyl aconitine (2) can desensitize Na⁺ channels after persistent activation. Lappaconitine (3), N-deacetyllapaconitine (4), 6-benzoylheteratisine (5), and 1-benzoylnapelline (6) deactivate these channels. Methyllycaconitine (16), mainly found in Delphinium species, possesses an extreme affinity for the binding sites of α7 nicotinic acetylcholine receptors (nAChR) and contributes to a wide range of neurologic functions and the release of neurotransmitters. Several DAs such as bulleyaconitine A (17), (3), and mesaconitine (8) from Aconitum species have a drastic analgesic effect. Among them, compound 17 has been used in China for decades. Their effect is explained by increasing the release of dynorphin A, activating the inhibitory noradrenergic neurons in the β-adrenergic system, and preventing the transmission of pain messages by inactivating the Na⁺ channels that have been stressed. Acetylcholinesterase inhibitory, neuroprotective, antidepressant, and anxiolytic activities are other CNS effects that have been investigated for certain DAs. However, despite various CNS effects, recent advances in developing new drugs from DAs were insignificant due to their neurotoxicity.

C18-diterpenoid alkaloids in tribe Delphineae (Ranunculaceae): phytochemistry, chemotaxonomy, and bioactivities

This review systematically summarizes the C₁₈-diterpenoid alkaloid (DA) compositions isolated from the genera Aconitum and Delphinium in the Delphineae tribe (Ranunculaceae). A total of 117 distinct C₁₈-DA components have been reported, including 58 lappaconitine-type DAs, 54 ranaconitine-type DAs, and five rearranged-type DAs. These components mainly originated from plants from the subgenus Lycoctonum in the genus Aconitum or less frequently from plants within the genus Delphinium. Natural C₁₈-DAs have exhibited a wide range of bioactivities, including analgesic, antiarrhythmic, anti-inflammatory, anti-tumor, and insecticidal activities, which are closely related to their chemical structures. The high chemical and biological diversities among the reported C₁₈-DA constituents in Delphineae plants indicated their potential as a vast resource for drug discovery. Additionally, the Delphineae plant C₁₈-DAs exhibited chemotaxonomic values and showed a high regularity of distribution at different taxonomic levels; therefore, the Delphineae plant C₁₈-DAs can serve as good chemical molecular markers in the taxonomic treatment of plants within this tribe, especially in the infrageneric division.

This review systematically summarizes the C₁₈-diterpenoid alkaloid (DA) compositions isolated from the genera Aconitum and Delphinium in the Delphineae tribe (Ranunculaceae).

Chemistry and biological activities of hetisine-type diterpenoid alkaloids

Hetisine-type C₂₀-diterpenoid alkaloids (DAs) are one of the most important DA subtypes. During the past decades, a total of 157 hetisine-type DAs were obtained from plants from seven genera in three families, most of which were isolated from the genera Aconitum and Delphinium in the Ranunculaceae family. Structurally, hetisine-type DAs are characterized by a heptacyclic hetisane skeleton formed by the linkage of C(14)–C(20) and N–C(6) bonds in an atisine-type DA, and their structural diversity is created by the states of the N atom and various substituents. Pharmacological studies have revealed a wide range of pharmacological actions for hetisine-type DAs, including antiarrhythmic, antitumor, antimicrobial and insecticidal activities, as well as effects on peripheral vasculature, which are closely related to their chemical structures. In particular, the prominent antiarrhythmic effects and low toxicity of hetisine-type DAs highlight their potential in antiarrhythmic drug discovery. Hetisine-type DAs with diverse bioactivities are promising lead structures for further development as commercial agents in medicine.

Natural hetisine-type C₂₀-diterpenoid alkaloids with diverse structures showed multiple pharmacological activities, indicating great potential in drug discovery.