Aconite alkaloids aconitine

Aconite alkaloids Aconitine, molecular formula C34H47NO11, is an example of an aconite alkaloid. It is soluble in organic solvents, e.g. CHCI3 and CeHg, and sfightly soluble in alcohol or ether, but insoluble in water. Aconitine is an extremely toxic substance obtained from the plants of the genus Aconitum (family Ranunculaceae), commonly known as aconite or monkshood . It is a neurotoxin, and used for creating models of cardiac arrhythmia. 

Abrine, 484 Abrotine, 772 Abrtis precatorius, 484 Abuta spp., 371 Acacia spp., 771 Acetylcholine, 262, 518 Acetylomithine, 170, 171, 172 Achillea spp., 779 Achilleine achilletine, 779 Acolyctine, 686 Aconine, 673, 675, 679, 685 Aconines, nuclear structure, 693 Aconite alkaloids, 673 Aconitine, 673, 674, 775 oxidation products, 676 Aconitines, pharmacological action, 690 Aconitinone, 676 Aconitoline, 675... 

Research on diterpenoid alkaloids published during the past year has continued to expand the body of structural and synthetic information available on these complex plant bases. The structures of ten new alkaloids from Aconitum and Delphinium species, including seven new bisditerpenoid alkaloids, have been reported. Tlie most significant progress in methods of structure elucidation has been the very successful applications of n.m.r. to the study of complex diterpenoid alkaloids. The New Bruns wick group under Professor Karel Wiesner has continued its progress toward the syntheses of the Ci9-aconitine-type alkaloids. An historical account of the synthesis of talatisamine (1), the first synthesis of a hexacyclic aconite alkaloid, has been published. This work was reviewed in a previous Report. ... 

Both prepared and unprepared Sichuan aconite are available commercially. Sichuan aconite contains aconitine, a toxic alkaloid that affects the heart and the central nervous system (Bensky et al. 2004). Due to aconitine content, the unprepared root is highly toxic and is the primary herb associated with serious adverse events in traditional Chinese medicine hospitals in Hong Kong (Chan 2002 Chan et al. 1994a, 1994c Poon et al. 2006). Processing of Sichuan aconite root greatly reduces the content of aconitine (Chen and Chen 2004). The prepared root, that has been processed to reduce toxicity, is the subject of this entry. 

Research studies on the aconite alkaloids started at the beginning of the nineteenth century, and aconitine was isolated from Actinidia napellus in 1833. As for the Aconitum plants of Japan, Shimoyama made the first report in 1882, and the plain chemical structure of aconitine was reported in the 1950s [4]. The stereochemistry, including absolute configuration, of the aconitine skeleton was determined when the total synthesis delphinine, an aconitine-related alkaloid, was achieved in 1972 [5-7]. 

Most of the aconite species contain one or more characteristic alkaloids all of which are derivatives of isomeric aconines. The B.P,C, aconite is confined to the root (the leaf also contains similar alkaloids) of A, napellus, Linn., which contains the crystalline alkaloid aconitine (acetylbenzoyl-aconine), C34H47O11N, Mol. Wt. 645 8, with smaller proportions of noncrystalline alkaloids. 

This kind of reaction was first recorded for aconitine (p. 675) and it serves to emphasise the parallelism in reactivity, and probably therefore in structure, which exists between aconitine and delphinine and possibly between the whole range of aconite and larkspur alkaloids. 

Aconites, commonly called wolfsbane or monkshood, are species of Aconitum (Ranunculaceae), valued ornamental herbaceous plants, grown for their showy blue or purple flowers, which are shaped like a monk s cowl. Their alkaloid content, mainly in the roots, makes them some of the most toxic plants commonly encountered. The dried roots of Aconitum napellus were once used, mainly externally for relief of pain, e.g. in rheumatism. The toxic alkaloids (0.3-1.5%) are complex diterpene-derived esters. Aconitine (Figure 6.124) is the principal component (about 30%) and is a diester of aconine with acetic and benzoic acids. Hydrolysis products benzoylaconine and aconine are also present in dried plant material. These alkaloids appear to behave as neurotoxins by acting on sodium channels. All species of Aconitum and Delphinium are potentially toxic to man and animals and must be treated with caution. 

The constitution of a number of alkaloids has not as yet been definitely established. Among these are aconitine from aconite, delphinine from larkspur, jervine and protojervine from veratrum viride, cevadine from sabadilla seed, lobeline from lobelia, the curare alkaloids from Chondro-dendron tomentosum, sanguinarine from sanguinaria, and many others. 

Aconitine (C33H43NO12) is found in various parts of Aconitum Napellus. It is particularly abundant in the tuberous root of this plant. If sections of aconite root are treated on a glass shde with solution of potassium permanganate, a red precipitate of aconitine permanganate will appear in the cells containing this alkaloid. 

Used by Moors in Europe in the 15th Century and earlier in India and China. Used by elephant hunters in India and said to have been tested in small arms ammunition at Buchenwald. Aconitine and delphinine alkaloids from the root of Aconitine napellus (aconite, monkshood, wolfsbane) and from the seeds of Delphinium staphisagria (starvesacre seeds). Delays repolarization due to impaired closure to Na channels. Weak diaphoretic was used in fevers. Local... 

Aconite contains, besides aconitine, three other alkaloids, if not a greater... 

Alkaloids of the Aconites.—The different species of Aconitam contain, probably, a number of alkaloids, but our knowledge of them is as yet extremely imperfect. The substances described as aconitin. lycoctanin, napellin are impure." It appears, however, that the principal alkaloids of aconitum napellus and of A. ferox, although differing from each other, are both compounds formed by the union of aeonin, CseHsgITOii, with the radical of benzoic acid in the former, and with that of veratric acid in the latter. 

Sichuan aconite may be prepared in several ways, the most common of which is to cook the herb at boiling temperature for several hours. Such processing reduced the toxicity of Sichuan aconite to between 1/2000 and 1/4000 of the toxicity of the unprocessed herb (Chen and Chen 2004). Heat processing at temperatures above 120°C for 50 minutes decreased the diester alkaloids, such as mesaconitine, aconitine, and hypaconitine, and increased monoester alkaloids, such as benzoylmesaconine, benzoylaconine, and benzoyl-hypaconine, whereas heating to 105°C preserved the diester alkaloids (Taki et al. 1998). 

Aconitine an extremely poisonous ester and alkaloid (see Terpene alkaloids) from the roots of aconite (Aconitum napellus) and other Aconitum and Delphinium species. Between 1 and 2 mg A. causes death in adult humans by paralysing the heart and respiration. In spite of useful physiological properties, A. is rarely used clinically, due to its toxidty. A. is sometimes used internally as a tincture for rheumatism and neuralgias, and externally as a pain-killing salve. In antiquity, aconite preparations were used as arrow poisons by the Greeks and (East) Indians. Its hydrolysis products are only slightly toxic. 

Aconitum alkaloids a group of terpene alkaloids, some of them very poisonous, from various aconite (Aconitum) species. The best known representative is Aconitine (see). 

The most toxic alkaloids of aconite, such as aconitine, mesaconitine, hypaconitine, etc., are known to possess arrhythmogenic effect. Aconitine itself has long been used to induce arrhythmia in experimental models [38, 39]. Aconitine and its structural analogues induce ventricular ectopics, ventricular tachycardia, torsades de pointes, and ventricular fibrillation in a dose-dependent manner. Aconitine has a positive inotropic effect on the heart. It has hypotensive and bradycardic actions [40]. Another group of diterpenoid alkaloids possessing C18 and C19 skeleton, such as lappaconitine, A -deacetyllappac(Miitine, heteratisine, and 6-benzoylheteratisine, are... 

Aconite is a strong and fast-acting poison, affecting both the heart and the central nervous system. Its active principles are aconitine and its related alkaloids. As little as 2 mg aconitine may cause death from paralysis of the heart or respiratory center. The lethal dose for adults generally ranges only from 3 to 6 mg of aconitine, readily contained in a few grams of plant material (frohne and pfander). 

To the percolate add 30 ml of N sulphuric acid, or sufficient to render the mixture faintly acid, shake well, allow to separate and run off the lower layer. Continue the extraction with 10-ml portions of 0-lN sulphuric acid until extraction of the alkaloids is complete, as shown by the iodine test. Wash the mixed acid solutions with about 10 ml of chloroform and run off the latter into a second separator containing 20 ml of 0 1 N sulphuric acid, shake, allow to separate and reject the chloroform. Repeat the washing of the liquid in the first separator with two further 5-ml quantities of chloroform, transfer each in turn to the second separator, wash with the same aqueous acid liquid, allow to separate and reject the chloroform layer as before. Transfer the acid liquid from the second separator to the first separator, make just alkaline with dilute ammonia solution and add 2 ml in excess shake with successive portions of chloroform until complete extraction of the alkaloids is effected, washing each chloroform extract with the same 20 ml of water contained in another separator. Remove the chloroform by distillation, add to the residue 2 ml of dehydrated ethanol, evaporate at a temperature not exceeding 60, and dry at a temperature below 60for thirty minutes. Dissolve the residue in 2 ml of neutral 95 per cent ethanol, warm until dissolved, add 20 ml of 0 02N sulphuric acid and 10 ml of water cool and titrate with 0-02N sodium hydroxide, using methyl red as indicator. 1 ml of 0-02N acid = 0-01291 g of the alkaloids of aconite calculated as aconitine. 

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