Alkaloids solvents

RSP,yOh,Uncaria and Gardneria alkaloids Solvent system optimization procedure Spherosil X0A-600, 5 ym or Wakogel LCH-10, 10ym 100x0.5 n-hexane-THF, CH.Cl.-DEA, CHCl.-MeOH, THF-MeOH in varibus ratios J Stepgradient CH,Cl,-Me0H-DEA(100 0.1 0.01) to (100 110.6l) 42 ... 

Ergot alkaloids and their salts form solvent complexes with the solvent of crystallization. This will cause breakdown of the alkaloid. Solvent complexes are broken off (dried) by heating the alkaloid in high vacuum till constant weight or for approximately one hour. 

Alkaloid Solvent —NH- Ester and oxindole Double carbonyl bond Others... 

Alkaloid Molar proportion of alkali Concentration of alkaloid Solvent [aln Refer- ences... 

In the commercial extraction of alkaloids from the drugs in which they exist, the powdered drug, or an alcoholic extract of it, is treated with an alkali such as ammonia or lime to liberate the alkaloid and the alkaloid is then extracted by means of an organic solvent. The crude material thus obtained is purified and finally crystallized either as the base itself or as its water-soluble salts. 

C8H10N4O2. An alkaloid occurring in tea, coffee and guarana, from which it may be prepared by extraction, It is also manufactured by the methylation of theobromine and by the condensation of cyanoacetic acid with urea. Crystallizes with H2O or anhydrous from organic solvents. M.p. (anhydrous) 235"C, sublimes at 176 C. Odourless, and with a very bitter taste. Caffeine acts as a stimulant and diuretic, and is a constituent of cola drinks, tea and coffee. 

Miscellaneous Pharmaceutical Processes. Solvent extraction is used for the preparation of many products that ate either isolated from naturally occurring materials or purified during synthesis. Among these are sulfa dmgs, methaqualone [72-44-6] phenobarbital [50-06-6] antihistamines, cortisone [53-06-5] estrogens and other hormones (qv), and reserpine [50-55-5] and alkaloids (qv). Common solvents for these appHcations are chloroform, isoamyl alcohol, diethyl ether, and methylene chloride. Distribution coefficient data for dmg species are important for the design of solvent extraction procedures. These can be determined with a laboratory continuous extraction system (AKUEVE) (244). 

Rya.nia., The root and stem of the plant yania speciosa family Flacourtiaceae, native to South America, contain from 0.16—0.2% of iasecticidal components, the most important of which is the alkaloid ryanodine [15662-33-9] C25H250 N (8) (mp 219—220°C). This compound is effective as both a contact and a stomach poison. Ryanodine is soluble ia water, methyl alcohol, and most organic solvents but not ia petroleum oils. It is more stable to the action of air and light than pyrethmm or rotenone and has considerable residual action. Ryania has an oral LD q to the rat of 750 mg/kg. The material has shown considerable promise ia the control of the European com borer and codling moth and is used as a wettable powder of ground stems or as a methanohc extract. Ryanodine uncouples the ATP—ADP actomyosia cycle of striated muscle. 

In practice a few iodine crystals are usually placed on the bottom of a dry, closed trough chamber. After the chamber has become saturated with violet iodine vapor the solvent-free plates are placed in the chamber for 30 s to a few minutes. The iodine vapor condenses on the TLC layers and is enriched in the chromatogram zones. Iodine vapor is a universal detector, there are examples of its application for all types of substances, e.g. amino acids, indoles, alkaloids, steroids, psychoactive substances, lipids (a tabular compilation would be too voluminous to include in this section). 

Arecoline, CgHj 302N. This, the most important alkaloid of areca nut, is an odourless, alkaline oil, b.p. 209°, volatile in steam, miseible with most organic solvents and water, but extractable from the latter by ether in presence of dissolved salts. The salts are crystalline, but usually deliquescent the hydrobromide, B. HBr, forms slender prisms, m.p. 177-9°, from hot alcohol the aurichloride, B. HAUCI4, is an oil, but the platinichloride, B2. H2PtClg, m.p. 176°, crystallises from water in orange-red rhombs. The methiodide forms glancing prisms, m.p. 173-4°. 

Meconidine, C21H23O4N. This alkaloid was prepared by Hesse and its existence in Japanese opium was confirmed by Machiguchi. It is a brownish-yellow, amorphous substance, m.p. 58°, easily soluble in alcobol, most organic solvents and in alkalis. It gives a green solution with sulphuric acid. The salts are amorphous. Meconidine is said to exhibit a slight tetanising action. 

Bebeerine, CjjHjgOjNj. This alkaloid has been described imder various names, pelosine, chondrodendrine, chondodendrine and curine (Z-form) whose origin is described elsewhere (pp. 363 and 374). It crystallises with one molecule of benzene, m.p. 161°, or 213° (solvent-free) or from methyl alcohol, m.p. 214°, and has [ajn 298° (EtOH) for the d- or Z-form (Scholtz ). Spath et recorded m.p. 221-221-5° (vac.) for both forms and + 332° and — 328° for the d- and Z-forms, in pyridine. 

Alkaloids of Pot Curare. This variety of curare is a dark brown, comparatively dry extract. According to Boehm, it contains protocurine, colourless hair-like needles, m.p. 306° (dec.), a base of low toxicity and yielding crystalline salts. A second alkaloid of similar type is protocuridine prisms, m.p. 274-6°, sparingly soluble in all ordinary solvents. The poisonous constituent is protocurarine, a red powder, easily soluble in water, and giving characteristic colour reactions with nitric acid and with oxidising agents in sulphuric acid, this latter reaction indicating a Strychnos spp. as a possible botanical source. 

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