Dry extraction

Filter the dried extract, and then distil off the ether from a small flask, using the customary precautions if the volume of ether is large, fit a dropping-funnel to the flask so that the ethereal extract can be run into the flask as the ether distils off cf. Fig. 23(E), p. 45). When the ether has been removed, replace the water-condenser by an air-condenser, and continue... 

When the reaction has subsided, boil the reaction-mixture under reflux for 2 hours then make it alkaline with sodium hydroxide solution, and distil it in steam until oily drops no longer come over in the aqueous distillate (1 2 litres). Extract the distillate thoroughly with ether ca. 150 ml.), and dry the ethereal extract over powdered sodium hydroxide. Filter the dry extract through a fluted filter-paper moistened with ether into a 200 ml. flask. Fit the flask with a distillation-head, or a knee-tube , and distil off the ether. Now replace the distillation-head by a reflux water-condenser, add 10 ml. of acetic anhydride, and boil the mixture under reflux for 10 15 minutes. 

The crude base is purified by converting 2g of base in toluene (3.3mL) into the acetate salt by heating at 65-70 with 0.46g of AcOH and the crystals are collected and dried (0.96g from two crops m 141-143 ). The acetate salt is dissolved in warm H2O, basified with aqueous NaOH and extracted with C6H6. The dried extract (MgS04) is evaporated in vacuum leaving a viscous oil which crystallises and can be distd. [Gottstein and Cheney J Org Chem 30 2072 1965.] The picrate has m 234-236 (from aq MeOH), and the formate has m 147-148° (from heptane). 

Spray-dried extract The solutions containing the drug extracts, which are sprayed through a nozzle, sink in the form of fine droplets in the current of warm air, losing their moisture and reaching the separator as dry and hollow pellets of extract which can be recognized with a hand lens. The spray-... 

Tn comparing the content of drug extract in the final product, teas in granule form are usually very much inferior to instant teas which arc prepared from spray-dried extracts teas in granular form, in addition to 97 -98% filler and carrier substances often contain only 2-3% dry extract, while in spray-dried products almost ten times as much, viz on average 20%, drug extract is present. 

Although acid caseins are employed for a number of purposes, rennet caseins in which the protein remains associated with calcium and phosphate are preferred for plastics applications. Rennet is the dried extract of rennin, obtained from the inner lining of the fourth stomach of calves, and is a very powerful coagulant. As little as 0.2 parts per million are said to be sufficient to coagulate slightly acidic milk. Its coagulating power is destroyed at 100°C. 

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. 

Trocken-element, n. dry cell, -entgasung, /. dry distillation, -extrakt, m. dry extract, -farbe,/. dry color, pigment pastel color. 

A mixture of 16.3 g of (2-chloro-5-methylphenyl)glycidic ether (from epichlorohydrin and 2-chloro-5-methylphenol) and 6.2 g of t-butylamine in 50 ml of ethanol is heated at reflux for 6 hours. The solvent is removed, the residue Is washed with water and then extracted with benzene. The dried extract is evaporated to give 1-t-butylamino-3-(2-chloro-5-methylphen-oxy)-2-propanol. Treatment of the free base in benzene solution with dry hydrogen chloride yields the hydrochloride salt. 

An alternative purification can be effected by dissolving the reaction product in water. The ester base is liberated by rendering the clarified aqueous solution alkaline. Removal of the base from the alkaline solution is achieved by extraction with a Suitable solvent such as benzene or ether. The pure hydrochloride of diethylaminoethyl 2-chloro-4-aminobenzoate Is then precipitated from the dried extract by the addition of dry hydrogen chloride. After removal by filtration and recrystallization from ethanol it is found to have a melting point of 173° to 174°C. 

A solution of the piperidino-diol (9 grams) in acetic anhydride (18 ml) was heated at 90°C for 1 hour, the solution cooled, excess acetic anhydride destroyed by the careful addition of water, and the resulting solution carefully made alkaline with 2N caustic soda solution to precipitate a solid product. The soiid was dried, extracted with n-hexane and the solution filtered free of insoluble material before percolation down a column (4x1" diameter) of alumina. Eiution with n-hexane gave a fraction (4.2 grams) which was crystallized twice from ether to give the diacetate, MP 176°-180°C. 

Step B A solution of the 3-tert-butylamino-2-oxopropanol in a mixture of pyridine hydrochloride and pyridine is treated with p-toluenesulfonylchloride. The mixture is stirred for /i hour at 25° to 30°C and then poured into cold water. The solution is treated with potassium carbonate and the pyridine evaporated in vacuo at a temperature between 55° and 60°C. The aqueous residue is treated with potassium carbonate and the mixture extracted with methylene chloride. Evaporation of the dried extract provides 1-toluene-sulfonyloxy-2-oxo-3-tert-butylaminopropane. 

A mixture of the dibenzodiazepinone 13 (R1 = H 7.0 g, 33 mmol), NaNH2 (1.04 g, 26.7 mmol) and dioxane (200 mL) was refluxed for 1 h, cooled to 60 C and 3-chloro-/V,/V-dimethylpropylamine (3.06 g. 25.2 mmol) in dioxane (40 mL) was added over 30 min. The mixture was boiled under reflux for 4 h, cooled and treated with McOH (10 mL). The filtered solution was evaporated under reduced pressure and the residue was extracted with cold dil HC1. The filtered extract was made alkaline with aq NH3 and extracted with Et20. The dried extract was evaporated to yield the product mp 116-119 C (EtOH/Et20). 

A mixture of a 4-azidopyridine (0.9-1.0 g), 28% NaOMe/MeOH (10 mL. large excess), MeOH (65 mL) and dioxane (75 mL) was irradiated under N2 with a 400-W high-pressure Hg lamp equipped with a Pyrex filter, the apparatus being internally cooled with running water. When TLC showed that all starting material had been consumed (3 4 h), the solvents were distilled off under reduced pressure and the residue was treated with ice-water (30-50 mL). The aqueous mixture was extracted with hexane or benzene and the dried extract was evaporated in vacuo, leaving the product as an oil, which was purified by chromatography (Scphadex or silica gel, benzene). 

A stirred suspension of the thioscmicarbazidc 1 (30.75 g, 0.15 mol) in i-PrOH (40mL) was treated with Na (3.45 g, 0.15 g-atom) over 30 min. After 14 h, the mixture was acidified with HOAc. H20 (10 mL) was added, and the whole was extracted with CI1CI3. The dried extract was evaporated leaving the product [yield 3.80 g (15 Vo)] whifch was purified by sublimation mp 102-103 C. 

A mixture of 1,2-dibromo-4,5-di(phenoxymethyl)benzene (2.24 g. 5 mmol), CuCN (2.24 g. 25 mmol), and DMF (10 mL) was refluxed for 8.h. then cooled, and poured into NH4OH (50 mL). The mixture was stirred for 10 min and the product was isolated by suction and washed with H20. The resulting bluish powder was dried, extracted with acetone, dissolved in II2S04 (20 mL), filtered, and the filtrate slowly added to crushed ice (150g), The mixture was stirred overnight and the precipitate isolated by suction, washed with 11,0 until neutral, and dried at 100 C yield 1.2 g (70%). 

A7M aqueous solution of LiOII-H20 is added to a 0.35 M solution of the sultam 11 in THF and vigorously stirred at 65 "C for 3 — 5d. Evaporation in vacuo, trituration of the residue with CH2CI2 and evaporation of the dried extracts gave sultam R NH. Acidification of the CH2C12 insoluble residue with 2N aq HC1, saturation with NaCl, extraction with CU2C12 and evaporation of the dried (MgS04) extracts gave the crude carboxylic acid 12 which is purified by distillation. 

Add 100 pi 1 of MSTFA reagent to less than 1 mg of dry extract. Heat at 60° for 15-20 min. If necessary, add 250 /a 1 of acetonitrile or other suitable solvent. For additional structural information, prepare the methoxime-TMS derivative to determine if one or more carbonyl groups are present. 

Add 250 /a 1 of methoxime hydrochloride in pyridine (MOX1 reagent to less than 1 mg of dry extract. Let this solution stand at room temperature for 2 hours. Evaporate to dryness with clean, dry nitrogen. Add 250 /a1 of MSTFA reagent and let stand for 2 hours at room temperature. 

A. Preparation of TMS Derivatives Add 0.25 ml of TRI-SIL TBT reagent (the only reagent we found to react with the hydroxyl group in position 17) and 0.25 ml of pyridine to the dried extract. Cap tightly and heat at 60° for 1-12 hours or overnight. 

Dry extracts or powders are made by spray drying the strong infusions after they have been concentrated to 40-50% solids (the catechin content is above 25% w/w). The residual water content is less than 5% w/w and the extract is usually processed as a powder containing inert processing aids to render it suitable for a variety of uses (tablets, capsules, dry mixes, etc.). 

LEMAR K M, TURNER M p, LLOYD D (2002) Garlic (AlHum sativum) as an anti-Candida agent a comparison of the efficacy of fresh garlic and freeze-dried extracts. JAppl Microbiol. 93 398-405. 

Common pharmaceutical products of olibanum and salai guggul are tablets prepared from dried extracts of boswellic adds, which are obtained by processes involving treatment of the resins with alkali and acid. The stress involved in this treatment is expected to lead to alteration of some triterpenes as, e.g., the conversion of the unstable 3-(9-acetyl-ll-hydroxy-[3-boswellic acid (compound 12) to the stable compound 3-(9-acetyl-9,ll-dehydro-[3-boswellic acid (compound 13). Two-dimensional TLC is an excellent means of observing this conversion [5]. For verification of this process, the substances have to be isolated by PLC and identified by GC-MS. 

Transfer the concentrate from Section 6.1.1 into a 200-niL separatory funnel with a small amount of water and add 10 mL of saturated sodium chloride solution. Extract three times with 50 mL of n-hexane (a free form of fluthiacet-methyl is present in the aqueous layer see Section 8). Dry the n-hexane extract through 80 g of anhydrous sodium sulfate on a glass funnel and transfer the dried extract into a 300-mL separatory funnel. Extract twice with 70 mL of acetonitrile, collect the extract in a 300-mL round-bottom flask, and evaporate the solvent under reduced pressure. Dissolve the residue in 10 mL of n-hexane-ethyl acetate (4 1, v/v), transfer the solution to a Bond Elut LRC SI column and discard the first eluate. Connect a Sep-Pak Plus NH2 cartridge to the outlet of a Bond Elut LRC SI cartridge and elute fluthiacet-methyl with 15 mL of n-hexane-ethyl acetate (2 3, v/v). Collect the eluate in a 50-mL pear-shaped flask, evaporate the solvent under reduced pressure and dissolve the residue in an appropriate volume of acetone for analysis. 

Transfer the sample extract (from Section 6.1) into a 300-mL separatory funnel, add 50 mL of water and extract the sample with 50 mL of n-hexane three times. Separate and dry the n-hexane layer with anhydrous sodium sulfate (plug the funnel with absorbent cotton and 50 g of anhydrous sodium sulfate), and collect the dried extract in a 300-mL of separatory funnel. Add 50 mL of acetonitrile to the separatory funnel and mix well for partitioning with the n-hexane extract three times. Collect the... 

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