Delphinine is a

toxic Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subst ...

diterpenoid Diterpenes are a class of terpenes composed of four isoprene units, often with the molecular formula C20H32. They are biosynthesized by plants, animals and fungi via the HMG-CoA reductase pathway, with geranylgeranyl pyrophosphate being a primar ...

alkaloid Alkaloids are a broad class of natural product, naturally occurring organic compounds that contain at least one nitrogen atom. Some synthetic compounds of similar structure may also be termed alkaloids. Alkaloids are produced by a large varie ...

found in plants from the ''

Delphinium ''Delphinium'' is a genus of about 300 species of annual and perennial flowering plants in the family (biology), family Ranunculaceae, native species, native throughout the Northern Hemisphere and also on the high mountains of tropical Africa. T ...

'' (larkspur) and '' Atragene'' (a clematis) genera, both in the family ''

Ranunculaceae Ranunculaceae (, buttercup or crowfoot family; Latin "little frog", from "frog") is a family (biology), family of over 2,000 known species of flowering plants in 43 genera, distributed worldwide. The largest genera are ''Ranunculus'' (600 spec ...

''. Delphinine is the principal alkaloid found in '' Delphinium staphisagria'' seeds – at one time, under the name stavesacre, a very well known herbal treatment for body lice. It is related in structure and has similar effects to

aconitine Aconitine is an alkaloid toxin produced by various plant species belonging to the genus ''Aconitum'' (family Ranunculaceae), commonly known by the names wolfsbane and monkshood. Aconitine is notorious for its toxic properties. Structure and rea ...

, acting as an

allosteric modulator In pharmacology and biochemistry, allosteric modulators are a group of substances that bind to a receptor to change that receptor's response to stimuli. Some of them, like benzodiazepines or alcohol, function as psychoactive drugs. The site that a ...

of voltage gated sodium channels, and producing low blood pressure, slowed heart rate and abnormal heart rhythms. These effects make it highly poisonous ( 1.5–3.0 mg/kg in rabbit and dog; frogs are ~10x more susceptible). While it has been used in some alternative medicines (e.g. in

herbal medicine Herbal medicine (also called herbalism, phytomedicine or phytotherapy) is the study of pharmacognosy and the use of medicinal plants, which are a basis of traditional medicine. Scientific evidence for the effectiveness of many herbal treatments ...

), most of the medical community does not recommend using it due to its extreme toxicity.

Isolation

One of the earliest reports of the isolation of delphinine, from ''D. staphisagria'', was that of the French chemists Lassaigne and Feneulle, in 1819. A less antique and more accessible report is that of the USDA chemist L. N. Markwood, who also briefly reviewed the earlier isolation work. Notably, these early isolations were carried out without the aid of

chromatography In chemical analysis, chromatography is a laboratory technique for the Separation process, separation of a mixture into its components. The mixture is dissolved in a fluid solvent (gas or liquid) called the ''mobile phase'', which carries it ...

, since delphinine crystallizes readily from a

petroleum ether Petroleum ether is the petroleum fraction consisting of aliphatic hydrocarbons and boiling in the range 35–60 °C, and commonly used as a laboratory solvent. Despite the name, petroleum ether is not an ether; the term is used only figurativ ...

extract after the typical acid-base cycling used in traditional plant alkaloid-extraction methods.

Chemistry

Despite the relative ease of isolation and early discovery of delphinine, its molecular structure was not established in its currently accepted form until the early 1970s. At that time, Wiesner's research group corrected the

stereochemistry Stereochemistry, a subdiscipline of chemistry, studies the spatial arrangement of atoms that form the structure of molecules and their manipulation. The study of stereochemistry focuses on the relationships between stereoisomers, which are defined ...

of the methoxy group at C-1 from the β- to the α-

configuration Configuration or configurations may refer to: Computing * Computer configuration or system configuration * Configuration file, a software file used to configure the initial settings for a computer program * Configurator, also known as choice board ...

. Thus, any drawing of the delphinine molecule appearing before 1971–1972 is likely to show the incorrect stereochemistry at C-1.

Pharmacology

As a result of its early discovery and isolation in crystalline form (then considered a criterion of purity), the pharmacological properties of delphinine were extensively investigated in the 19th century, despite the fact that its molecular structure was unknown. It is likely that some of these investigations were carried out with impure drug and should be interpreted with caution. References to and commentary on these early studies may be found in the review by Benn and Jacyno. More recent studies focused on the

cardiovascular In vertebrates, the circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the body. It includes the cardiovascular system, or vascular system, that consists of the heart a ...

toxicity of delphinine. In general, the pharmacology of delphinine seems to resemble that of

, although the acute toxicity of delphinine appears to be lower than that of aconitine in test animals.

References

{{reflist, 30em Plant toxins Delphinium Clematis Alkaloids Benzoate esters Tertiary alcohols Ethers Acetate esters