Veratrine alkaloids

Rhododendron sinensis Sw. Yang Zhi Zu (Chinese rhododendron) (flower) Andromedotoxin, veratrine alkaloids.49 This herb is toxic. Sedative, analgesic, anesthetic in rheumatism. 

Veratrin alkaloids are apparently absorbed across the skin and gut, and probably by the lung as well. Veratrin alkaloids have a digitalis-like action on the heart muscle (impaired conduction and arrhythmias). 

Much has been written of the veratrine alkaloids derived from plants of the Lilliaceae family. Many early studies were made with natural mixtures of plant alkaloids, and as different alkaloids have differing activities the results are com plex and confusing. From studies with a sin e alkaloid, veratridine [134], it was found with squid axon and frog nodes that the transient increase in sodium permeability was followed by a second, dow-developing permeabUity increase whidi did not undergo inactivation. In consequence, many excitable membranes show repetitive depolarisations in response to a sin e stimulus. The alkaloid is more active when applied to the inside of the membrane, and the cation appears... 

Veratrine alkaloids are cardiac depressants, and are used in medicine in the treatment of severe hypertension. Their action is mediated through inhibition of Na-K ATPase, the enzyme required for transport of mineral ions across cell membranes—an action they... 

Craig LC, lacobs WA (1943) Veratrine alkaloids. XX. Further correlations in the veratrine group. 

Commercial veratrine is a mixture of alkaloids prepared from sabadilla seeds and consists largely of cevadine and veratridine with some cevine. Its manufacture has been described by Schwyzer. Crystalline veratrine was first isolated by G. Merck. Wright and Luff introduced the name cevadine to distinguish this alkaloid from the commercial amorphous mixture known as veratrine. ... 

Jervine has also been recorded from other Veratrum spp., e.g., V. nigrum, V. lobelianum and V. grandiflorum and veratrine-like alkaloids in Zygadenus spp. (p. 779). 

Cevadine, C32H49O9N (crystallised veratrine), was first isolated in a crystalline condition from sabadilla seeds by G. Merek, who called it veratrine, and was subsequently obtained by Schmidt and Koppen,i and by Wright and Luff, whose name cevadine has been generally adopted, though Ahrens suggested that it should be called crystallised veratrine. The yield of total alkaloids from the seeds is said to be from 6 to 7 gm. per kilo, of which 0-8 to 0-9 gm. may be obtained as crystalline cevadine, 0-5 to 0-6 as veratridine and 0-2 to 0-3 as sabadilline. 

Veratridine (amorphous veratrine), CggHgiOuN. This alkaloid, probably identical with Schmidt and Koppen s water-soluble amorphous veratrine and with the amorphous veratrines of Wright and Luffi and G. Merck, was named veratridine by Bosetti. Its isolation from commereial veratrine has been described by Blount.It is a colourless powder, m.p. 160-180°, + 8 0° (EtOH). The sulphate, B. H2SO4.9H2O,... 

Neither the drugs yielding these alkaloids nor the alkaloids themselves are now recognised in the British or United States Pharmacopoeia, but the drugs still appear in non-official publications along with veratrine, which may be either amorphous, i.e., the mixture already referred to, or crystalline, i.e., the alkaloid cevadine. 

Veratridine. An alkaloid neurotoxin purified from veratrine. [McKinney et al. AB 153 33 1986]. 

Sabadilla consists of the powdered ripe seeds of a South American lily. It is used as a dust, with lime or sulfur, or dissolved in kerosene, mainly to kill ectoparasites on domestic animals and humans. Insecticidal alkaloids are those of the veratrin type. The concentration of alkaloids in commercial sabadilla is usually less than 0.5%. Little or no sabadilla is used in the United States today, but there is probably some used in other countries. 

Veratrine.— This alkaloid, with a composition of C37H53NOU, is found in varions parenchyma cells of Veratrum album. If sections of the rhizome or roots are mounted in 2 drops of water and a drop of concentrated H2SO4 and examined microscopically on a glass slide, the cell contents and walls of the cells which contain this substance first take a yellow color which soon changes to an orange-red and then to a violet. 

Veratrum alkaloids are produced by lilaceous plants of the suborder Melanthaceae of which Veratrum album, the hellebore of Europe and northern Asia, Veratrum viride, the swamp hellebore or Indian poke of North America, and Schoenocaulon officinale of Central and South America are the best known. The latter yields the sabadilla seed which was used as an insecticide by Indians in pre-Columbian times (Crosby 1971). The alkaloid fraction of the seeds, often termed veratrine, is a poorly defined mixture mostly of the ester alkaloids, veratridine, and cevadine and of the alkamine veracevine or its isomer cevine. 

In preparations whose intracellular space is not accessible,permeability ratios can be determined from differences, AErev, of reversal potential on changing the external cation concentration. Thus in frog muscle fibers treated with veratridine Pnh4/Pns=0.67 as compared to 0.11 in unmodified channels (Leibowitz et al. 1987). In frog nerve fibers treated with the alkaloid mixture veratrine PNa PNH4 PK= 1.0 0.61 0.29 was determined (Naumov et al. 1979), compared with control values for this preparation of... 

Alkaloids Detected by Picric Acid. Hager has facid precipitates various alkaloids from their solutions, such as brucine, strychnine, veratrine, quinine, cinchonine, and some alkaloids of opium. Morphine and atropine, however, are precipitated only from neutral and concentrated sol a lions, d the precipitate dissolves pretty easily in water, Glucosides, casein, and pseudo-morphine resist the action of tho picric acid. 

Alkaloids which modulate ion channels are tabulated in Table 10. Voltagegated Na+ channels are a target for several steroidal alkaloids, (e.g., batrachotoxinin, samandarine, veratrine, veratridine and zygadenine), indole alkaloids (e.g., ajmaline), aporphines (e.g., dicentrine, liriodenine), quinoline alkaloids (quinine, quinidine), quinolizidine alkaloids (e.g., sparteine, lupanine), and furthermore, for alkaloids present in animals or venoms (e.g., chiriquitoxin, i-conotoxins, dibromosceptrine, gonyauxtoxins, histrionicotoxins, pumiliotoxins, saxitoxin and tetrodotoxin). 

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