Pyrrolisidine alkaloids are a group of alkaloids of predominantly plant origin, containing a pyrrolisidine residue in their molecule. Pyrrolisidine alkaloids were found in 14 plant families, as well as in animal organisms. The plants of the genera Buzulnik ( Ligularia ) and Krestovnik ( Senecio ) from the family Astrova , Blackroot ( Cynoglossum ), Heliotrope ( Heliotropium ) and Trachelanthus from the Burachnikovy family, Crotolaria from the Bobov family are the richest in these alkaloids. In total, they were found in approximately 250 plant species [1] .
The biosynthetic precursor is diamine - cadaverine . One of its molecules is oxidized to gamma-aminobutyric aldehyde, which, reacting with an unchanged amine, forms a Schiff base. From it, pyrrolisidines are formed by subsequent oxidation, reduction, and cyclization reactions. Typically, plant-based pyrrolisidine alkaloids have the structure of complex non-nin alcohols with mono- (heliotrin) or dibasic polyfunctional necin acids.
Content
Classification
Pyrrolisidine alkaloids are usually divided into three groups [1] :
- non-ester alkaloids,
- monocarboxylic acid esters,
- macrocyclic diesters.
Non-ester alkaloids are usually viscous liquids or low melting crystals, highly soluble in water and organic solvents and strong bases. These include, in particular, heliotridine , trachelantamidine , 1-methylene-7-hydroxypyrrolisidine .
Esters of monocarboxylic acids are viscous liquids or crystalline low-melting substances; sparingly soluble in water and organic solvents; medium strength bases; often exist as N-oxides . Examples include indicin , lindelofin, and sarracin.
Macrocyclic diesters are crystalline high-melting substances, poorly soluble in water, but well soluble in organic solvents; weak bases. this group includes, for example, platifillin and trichodesmin. Some macrocyclic pyrrolisidine alkaloids are esters formed with the participation of otonecin or dihydropyrrolizinone . Among pyrrolisidine alkaloids there are chlorine-containing alkaloids, for example, lolidine [1] .
Often, plant alkaloids of pyrrolisidine are present as N-oxides. The vast majority of pyrrolisidine alkaloids are substances with high biological activity, but have high toxicity especially for human liver [2] . Some others exhibit antitumor activity ( trichodesmin , indicin N-oxide ) and exhibit antihypertensive properties.
The carcinogenic and hepatotoxic properties of pyrrolisidine alkaloids are manifested as a result of lethal synthesis , and the resonantly stabilized cation formed in the liver during the metabolism of pyrrolisidines is able to attack biological nucleophiles - proteins and nucleic acids , damaging their structure.
Medical Use
There are pyrrolisidine alkaloids used in medicine. Of the greatest importance among them are platyphyllin and sarracin, contained in plants of the genus Savior. Platyphyllin is a colorless crystal with a melting point of 129 Β° C; soluble in chloroform , worse in ethanol , benzene , acetone , insoluble in water. Forms picrate, iodomethylate, bitartrate.
Sarracin is a colorless crystal with a melting point of 51-52 Β° C; soluble in ethanol, diethyl ether, chloroform, slightly soluble in water. Forms picrate, bitartrate.
Raw materials for the industrial production of these alkaloids are Broadleaf Crossed ( Sonecio platiphyllus ) and Helical Crossed ( Senecio sarracenicus ). Platifillin and sarracin have anticholinergic and antispasmodic effects and are widely used for spasms of smooth muscles of the abdominal organs , bronchial asthma , arterial hypertension [1] [3] .
See also
- Pyrrolisidine
Notes
- β 1 2 3 4 Sadritdinov F.S., in the book: Pharmacology of natural compounds, Tashkent, 1979;
- β Radominska-Pandya, A (2010). "Invited Speakers." Drug Metabolism Reviews 42 (1):
- β Bull L. B., CuIvenor CCJ, Dick A. T., The pyrrolizidine alkaloids, Amst., 1968;