GLUCOSIDES OF EMODIN BY LEONARD ALBERT STIDLEY A. B. Carthage College, 1921 THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN CHEMISTRY IN THE GRADUATE SCHOOL OF THE UNIVERSITY OF ILLINOIS, 1922 URBANA, ILLINOIS PI ^ ' .*.1 *wl..ai .V . . 1 JS-’ *' t «v>^(lP'^KK£'^i ..... .*^-A '. * * ^ ^ iV’f '^,4fr ■ ■: . ■ ■, ^ wdOM3 iO/Jai8(foU42f' I f » : :'PMm ¥ S ' *'. ' -I^'i '. ' »* . ‘i' . ^' Nt •i^-,'*‘ '■ ‘ il-^. ' ^^.'- ;•% ■: \.^;m 'A < , .A !t;. ;■' * i -t; '9, t>» • ■' r-L, .}ij «M4 '' ,'Jd' ■■ ' .**v«iit» fpT '.inf* ’if-;.A * ^ whtt'A ii^.xt' ?»,w^ ki ' ; ' UNIVERSITY OF ILLINOIS THE GRADUATE SCHOOL 4 ^ 19 ^ I HEREBY RECOMMEND THAT THE THESIS PREPARED UNDER MY SUPERVISION BY Leonair., ., ..L_ -r.. J ENTITLED _ - giucosiaes E J l QCl in BE ACCEPTED AS FULFILLING THIS PART OF THE REQUIREMENTS FOR Recommendation concurred in* Committee on Final Examination* ^Required for doctor’s degree but not for master’s Digitized by the Internet Archive in 2015 https://archive.org/details/glucosidesofemodOOstid ACKNO’ii/LEDGUiENT The writer wishes to express his sincdre appreciation for the helpful suggestions and encouragement from Dr.. George D. Beal, under whose supervision this investigation was carried out. - 1 - I IlITRODUCTION AITD STATEMENT OF PROBLEM The name glucoside is applied to those substances, which under proper conditions furnish when hydrolysed by an enzyme or an acid, a sugar, usually dextro-glucose and one or more other compounds. Representatives of nearly every class of organic com- pounds occur in plants, chiefly in the fruit, bark and roots, in combination with a sugar. These natural glucosides first drew attention in plant anal- ysis, because of their various useful properties in medicine and the arts. The properties of the hydrolyised constituents have been studied more than the glucosides themselves. Some of the naturally occurring glucosides have been prepared synthetically. These syntheses have included the classes of alco- hols, phenols, aldehydes, ketones, alkyls, amines, mercaptans, and acids combined with sugar, Goyre spending representatives of these classes have been found to occur in plants. Investigations of plants have revealed natural glucosides of anthraqui nones and sugars. This work was undertaken with the hope of synthesizing a dihydroxy anthraquinone and trihydroxymethylanthraquinone-glucoside,. corresponding to the form that is found in the plants. - 3 - II HISTORICAL The hydroxyanthraquinones have long been known empirically, because of their dyeing and purgative properties. Before the synthesis of dyes, alizarin was the most valuable natural material in the dyeing industry. Alizarin, 1-3 dihydroxyanthrquinone, is the principle con- stituent of the madder root, Rubia tinctorium, in which it occurs as a glucoside, ruberythric acid. The first discovery of import- ( 1 ) anoe was made by Robiquet and Colin, who in 1836, succeeded in preparing from madder a substance which on being subjected to heat gave a sublimate consisting of beautiful reddish-yellow needles, and to which they gave the name alizarin. The method which they adopted left it quite uncertain whether or not it was a product of decomposition of some other body formed by the action of heat. The same series of experiments led to the discovery of another coloring mtter in the madder to which these chemists gave the namie purpurine. This was also a hydroxyanthraquinone glucoside. In the year of 1835 a memoir was published by Runge containing a deLscription of the properties and methods of oreparation of (3) three distinct coloring matters from madder. In 1838 Decaisne in an extensive study of the madder root stated that the effect of oxygen upon the yellow colored substance produced the red dye, (3) Rochleder had the view first that alizarin and the glucose were connected in ruberythric acid in the ratio of two molecules of - 3 - glucose to one of alizarin. ^ HgO ^ 3 C 0 H 13 O 6 C 14 K 8 O 4 Ruberythric acid was obtained from extracting powdered madder root with absolute alcohol. The yield was 0.1^ of the v/eight of the dried root. The compound formed lemon-colored needles of silky luster, which melted at 358-860 degrees. In 1860, (4) Schunk claimed to have isolated another glucoside which yielded an anthraquinone upon hydrolysis. This new substance he called rubianic acid, and which he did not think was identical with Rochleder' s ruberythric acid. Schunk claimed that it did not pre-exist in the plant, but that it v/as formed by the action of oxygen upon a more complex body. Schunk showed that alizarin and purpurine T;ere allied substances, since both yielded phthalic acid when they were decomposed by nitric acid, and napthalene was (5) the only substance which was known to yield this. Stokes drew up a table to show the differences in physical properties between ( 6 ) alizarin and purpurine. Schunk and Ivlarchlewski showed that rubi-^ j anic acid was a methyl substitution product of purpuroxanthin, which was an isomer of alizarin, obtained from purpurine by "de- oxidation. ” They also isolated another hydroxyanthraquinone glucoside (rubiadin glucoside) which yielded upon hydrolysis, rubj^in and glucose. Liebermann and Bergami showed that rubery- thric acid contained one of the two hydroxy groups of alizarin in a free state, and that the union of the alizarin with the sugar took place through that hydroxyl which may be easily - 4 - alkylated. Since ruberythrio acid yields am octa-acetyl deriv- ative the following formulae for the compound were suggested with preference to the second: (1) g,,h.o ^ V - \oC5H^^03 (2) 14^6 H^O 00 ^ 2 ^ 2 1®10 OH ( 8 ) In 1897 Perkin studied the yellow coloring matter of the madder (9) root, but isolated no new products. LJuller and de la P.ue isolated from rhubarb root some anthraquinone glucosides, which yielded emodin and chrysophanic acid upon hydrolysis. Later, ( 10 ) Muller isolated alizarin by hydrolysis of the same root. Per- haps no drug recognized by any of the national pharmacopoeias has more frequently engaged the attention of chemists than rhubarb. ( 11 ) According to Tutin and Clewer , the anthraquinone glucosides which have been isolated from that plant are rhein, emodin, aloe- emodin, emodin monomethyl ether, chrysophanic acid and rhelnolic (13) aold. Jowett and Potter analvsed araroba to study ohrysarotln, (13) the anthranol of chrysophanic acid. Tutin found that anthra- quinone derivatives present in senna were rhein and aloe-emodin. (14) Bailey considers that chrysophanic acid is a constituent of senna. The bark and fruit of several species of the Rhamonaoaae contain several anthraquiijjes in combination about which there is some dispute. The buckthorns contain a glucoside to which the name frangulin has been given and which yields upon hydrolysis - 5 - rhamnose and emodln. li 0 ? 1 9 ? G H , 0^-f- G H 0^ 6 14 6 15 10 5 (15) Frangulin ms first separated by Blns'.vanger in Rharmus francmla, (16) and ms recognized as a glucoside by Faust. Frangulinic acid is the primary glucoside of Rhamnus frangula and has been iso- (17)' (18) lated in Cascara segrada. Gunton in his work on a rein- vdstlgation of the proximate composition of Rhamnus frangula en- countered the natural frangulin, and subsequently 7/orked upon the synthesis of the glucosides of this type, (19) The s^mthetic ’work on glucosides was begun then Colley by the use of acetocloroglucose was able to effect a combination of this compound with the potassi'um salt of the phenols and alco- (30) hols. Micheal was able to combine glucose in 1he form of the acetoohloroglucose with a simple phenol. This product agreed ’with the natural o courting glucoside. This was followed by the syn- (31) thesis of helicin, salicin, and methyl arbutin. Plugo Schiff produced compounds of aldehydes and ketones with the sugars thru the union of the components in acetic acid solution. By means of the acetoohloroglucose and the corresoonding bromo derivative, (33) Bruin formed the thymol glucoside and the ©< -napthol glucoside, , , (33) (34)1 Irvine synthesized aaiino glucosides from d-glucosamine. Ryan (35) used arablnose and xylose to form the glucosides. Llauthner (36f synthesized acid glucosides, Salaay fatty alcohol glucosides (37) (38) and Schneider mustard oil glucosides. Fischer and his students have synthesized the alkyl and phenolic glucosides. 6 ( 1 §) Gunton has been the only one to work upon the synthesis of the anthraquinone gluco sides. - 7 - III PREPARATION OF MATERIAL. (39) I. Preparation of Rhamnose. Following the method of Walton, two hundred grams of lemon flavin were suspended in two liters of water, acidified with about 0.5^ sulphuric acid and boiled for three hours. The yellow plastic material was filtered off and the filtrate neutralized with barium carbonate. It was then clarified with bone charcoal which removed the creamy color. The filtrate was then concen- trated under diminished pressure to a thick syrup of about 40fo solids. This sugar was diluted to three times its volume of abso- lute alcohol and the rhamnose crystallized out by concentrating the filtrate to a density of 70-60^ solids. Pure white crystals of rhamnose were obtained after recrystallization from absolute alcohol. The osazone melted at 180°. The first preparation yielded 18^ of the weight of the lemon flavin taken, and the second yielded 30^. (30) II, Preparation of Alizarin, Indicator Alizarin was used. It was sublimed by placing a beaker through which cold water was circulating over a crucible containing the alizarin. A Bunsen burner was applied gently until the sublimate could be seen forming. The flame ms kept at that heat. The yield was so small that it was necessary to synthesize some alizarin. 8 Ten grants of anthraquinone and 85 cc. of fuining sulphuric acid vfsre placed in a small flask and heated to 300-230®C. on an oil -bath, raising the temperature slowly, for about two hours. The mixture was allowed to cool and poured into 300 cc, of water, then filtered. 50 grams of salt was then added, and the solution stirred thoroughly and allowed to stand in cold water until the sodium anthraquinone sulphonate separated. The salt was filtered off, pressed and dried on a porous plate. Into an iron pipe which could be closed at both ends by means of a screw cap were put 40 grams of sodium hydroxide, 10 grams of sodium anthraquinone- sulphonate, 3 grams of potassium chlorate and 40 cc. of water. The bomb v/as heated in an electric oven for 30 hours at 170®C. The dark blue mass which resulted was dissolved in hot water, filtered and neutralized v;ith hydrochloric acid. The alizarin which was then precipitated was filtered off and dried. It v/as recrystallized from glacial acetic acid. (31) Preparation of Tetra-acetyl-bromo-glucose. The method of Dale was used with several minor alterations, T'.vanty-f ive grams of glucose were shaken in 135 cc. of acetic an- hydride. liydrobromic acid from the action of bromine upon red phosphorous was bubbled through the suspension until the acetic anhydride v;as saturated. The solution became a light green, and the glucose rapidly dissolved with the evolution of consider- able heat. After cooling the solution was dissolved in 300 cc. - 9 - of chloroform and the resulting solution washed to remove the acid, once with water and once with a solution of sodium bicarbon- ate, and then dried with calcium chloride to remove the water. It was then evaporated under diminished pressure to a thick yellow syrup, washed into a beaker with a small quantity of ether and the tetra-acetyl-bromo-glucose was precipitated with 15 vol- umes of petroleum ether. The compound came out in a semi-liquid state which solidified upon stirring. It had a yellow color and an acetyl odor. After recrystalizing twice by dissovling in 75 cc. of ether and evaporating the solution in a current of dry air until crystals began to appear the odor was lost and the com- pound was White. A sample melted at 88" agreeing with that of Dale, The various quantities which were made varied in yields from 65 -7 0'^ Preparation of aoetobromo -rhamnose Thirty grams of rhamnoae were suspended in one hundred and fifty cc. of acetic anhydride and hydrobromic acid prepared as in the case of acetobromoglucose, passed into the solution until it was saturated. The solution became a light brovTn and the rhamnose dissolved with the evolution of considerable heat. This solution was treated similarly to one in the above mentioned preparation. The product obtained was a dark brown syrup having an acetyl odor. Attempts were made to crystalize it from several solvents, but it still remained a liquid. The total yield was forty grams. The compound kept v/ell in stoppered bottles. - 10 - A Alizarin Glucoside. Five grams of acetylbromoglucoss were added to an absolute alcohol solution of 3.66 grams of alizarin and 1.'33 grams of potassium hydroxide in an Erlenmeyer flask. The flask was tightly stoppered and on shaking the mixture became a deep violet due to the formation of the potassium salt of the alizarin. This mixture was allowed to stand at outside temperature for one week with occasional shaking. It was then refluxed for one and one half hours. There was no visible change in the mixture at this time, for the deep violet color persisted. The alcoholic solution was then diluted with water and exactly neutralized with hydrochloric acid, which precipitated the dissolved material as a fine orange precipitate, having a strong odor. This was filtered off, dried and weighed. It weighed 3.67 grams. The orange bro^^Ti precipitate showed clearly that a mixture was present. No melting point could be secured. Part of the substance was free alizarin which had not entered into the reaction. The precipitate gave tests for the presence of glucose. Part of the precipitate was hydrolysed with dilute sulphuric acid. The solution turned a yellow shade, crystals of alizarin were evident, and the solution gave test for the presence of glu- cose. It was thought that this might have been present at the beginning of the hydrolysis, so the precipitate was washed and extracted with ether. The ether v;as evaporated and the residue was alizarin as was shovm by the orange crystals and the resulting melting point. - 11 The remaining precipitate was washed virith water until the wash water gave no tests for the presence of a carbohydrate. Then a portion was hydrolysed with dilute sulphuric acid. The resulting solution gave a test for sugar. It is possible that this may have resulted from an occlusion, rather than the forma- tion of a compound. Benzene, methyl alcohol, ethyl alcohol, arnyl alcohol, and chloroform were used as solvents in trying to secure a crystal ine product, but no positive results were obtained, The melting point at about 83®C. was not sharp. The precipitate was sorted mechanically, and vdiat appeared to be the best portion as taken and hydrolysed with dilute sulphuric acid, but the resulting solution did not give tests for the presence of glucose. A check upon the experiment failed to y’eLd any other product, of a glucosidic nature. Owing to the fact that there was an excess of alizarin, in the first experiment, another experiment tise same as the first, but the amount of alizarin was reduced to 2.5 grams. After re- fluxing for one-half hour the solution was diluted and exactly neutralized with hydrochloric acid. The same orange colored precipitate was given. This was filtered and dried. ITo definite melting point was obtained. It wasLthen washed with ether to remove the free alizarin. The ether was evaporated and some free alizarin recovered as was shown by the melting point. The original yellov; precipitate showed no evidences of cr^rstalline form. 1 1 t1 n I! li , .1 'iiti »»•>, ^r.j . ,:t:' \ p. V. f' *‘^r: A I i A I' - 13 Alcohol, acetone and chloroform v;ere used in an effort to crystallize the powder, but because of its insolubility, nothing crystalline could be obtained. The substance gave tests for the presence of carbohydrates both before and after hydrolysis. The remaining precipitate was washed with water until no tests for sugar were given. Upon hydrolysis a slight test was obtained. V/hether or not this was due to an occlusion or to a combination could not be certain, hut because of the evident mixture of the substance the former seems more plausible. It was thought that perhaps a catalyst might aid in the reaction so the same proce.dure as in the last experiment was carried out with the addition of some mercury. The results failed to yield any evidence other than what v/ere given by the previous experiments. Thinking that perhaps the chlorine atom might be mors easily replaced on the acetyl derivative, 5 grams of acetyl cl^loro glucose prep3.red by the same method as the acetyl bromo glucose, v/ere added to an Erisnmeyer flask containing an absolute alcohol solution of 2.00 grams of alizarin and 1.33 grams of potassium hydroxide. This was refluxeddfor one hour and a half, diluted and exadstly neutralized with hydroohlorio acid. A light orange precipitate resulted. This wa.s filtered, washed and dried. It proved to be a mixture, and nothing crystalline could be isolated from it. : VJ: '. ’; :v* '■rr.-^r .. r- -v .. . „ - 13 ( 33 ) The successfiul synthesis of recorcinal o<, -glue ©side by the shaking process tempted us to try a similar procedure, because of the similarity between recorcinol and alizarin. Five grams of acetobromoglucose , 2.86 graiiis of alizarin and 1.33 grams of potassium hydroxide were added to 200 cc. of water. A blue solu- tion resulted. This sDolution was added to a bottle containing 400 cc, of ether. The bottle was securely attached to cross-arm support which was in turn connacted to a shaking machine driven by a motor. The bottle was shaken intermittently for tv/enty-four hours. 200 cc. of ether were then added and the bottle shaken for another tv/enty-f our hours, A heavy foam had appeared in the ethereal layer. This layer was separated from the aquous solu- tion, and the ether evaporated. A blue condensation product resulted. This substance proved to be insoluble in the ordinary organic solvents. A portion was subject to hydrolysis but did not yeild any carbohydrate test even after it had been hydrolysed for six hours. The product did not give a melting point below 300 degrees, nothing crystalline could be isolated from the blue Ish -black powder. (33) A recent modification for phenolic glucosides by Fischer was tried with the hydroxyanthraquinone. Five grams of acetobromo- glucose and 2.86 grams of alizarin were intimately mixed in a small beaker, to which was added four grams of dried quinoline. The beaker was then heated upon a water bath for two hours. It was then cooled through shaking ’with 100 cc. N Sulphuric acid and 75 cc. of chloroform, not all of the substance dissolved. The - 14 - o-iloroform was filtersd after it had teen washed with water sever- al times. The 3 chloroform solution was then evaporated upon a steam bath. A light brov/n viscous liquid with some uncombined alizarin remained. For the conversion into the acetate product, a portion of the viscouassubstance was mixed with 5 cc. of dried pyridine and 10 cc. of acetic anhydride. After slight shaking this dissolved. After standing 34 hours this solution was poured into ice water, and the light broi^m liquid collected at the bottom. To replace the acetyl groups by hydroxyls, two gfams of the tetra-acetyl product were dissolved in 100 cc. of v;ater which contained 8 grams of crystallized barium hydroxide, and 35 cc. of alcohol. This was heated to 50-60®C. for 5-6 hours with frequent shaking. The solution was colored a dark blue. This was due to the formation of the barium salt. Carbon dioxide was then passed through the warm solution and barium carbonate was precipitated. This was filtered off. The filtrate was evaporated under diminished pressure and a bro'.vn syrup was left. This was left to stand until it was dry. ^'^en viewed under the microscope no crystals of alizarin could be seen. The melting point was not sharp, but it would start to melt at about 85°C. The substance was washed with water until it gave no tests for carbohydrates. Water was allowed to cstand upon it for several days, and still there was no test for carbohydrates, A portion of the substance was then added to a dilute solution of sulphuric acid and hydrolysed for several hours. The resulting - 15 solution gave positive tests for the presence of carbohydrates and also showed free alizarin, because the latter was extracted with ether and after crystalization gave the melting point for alizarin, A mixture of emulsin. and raaltase was added to one gram of the substance and the mixture allowed to stand for several days at room temperature. The resulting solution showed evidence of hydrolysis by enzyme action because positive tests were given for glucose. Chloroform, alcohol, arnyl alcohol, acetone and methyl alco- hol were employed in trying to cryst^Jize the viscous liquid, but no positive results were obtained. Owing to the fact that the substance dissolved slov/ly in chloroform we tried to crystal- lize the substance from this solvent by means of a vacuum desib- dator. The chloroform solution containing the substance was placed in a desiccator. The vacuum pump was connected for about tv/o minutes. Then in about an hour it was again connected. This was continued until the solution had evaporated. But the sub- stance was again deposited as a viscous liquid. The use of this solvent in a tightly stoppered bottle was then resorted to. The substance was heated in a small bottle until a portion had 'dis- solved and a portion remained undissolved. The bottle was tightly stoppered and set aside, nothing crystalline formed. - 16 - In attempting a quantitative hydrolysis, two grams of the acetylated substance was dissolvea in a mixture of 35 cc. of chloroform and 10 cc. of dilute sulphuric acid, and the mixture hydrolysed for several hours. The chloroform layer after wash- ing was then evaporated, and the resulting substance weighed. The result gave ,1130 grams, or 58^ of the original substance. Taking ruberythric acid as a ba^is in which two molecules of glucose are united with one of alizarin the yield should be 68'^. If there was a union the basis of conjunction would favor the ratio of two to one rather than one to one. Owing* to the excess of alizarin which was left each time after the extraction of the mixed mass of alizarin and aceto- bromoglucose, different methods were tried in order to increase the amount of the amorphous substance which would remain. A mixture of 5 grams of acetobromoglucose and 3,86 grams of alizarin were dissolved in ten grams of quinoline and refluxed at 170° for one hour. The remaining quinoline ?/as extracted with dilute sulphuric acid and chloroform. It was evident that too much heat had been applied, because the resulting product was partially carbonized. Five grams of acetobromo glucose and 3.66 grams of alizarin were intimately mixed in a beaker and 4 grams of quinoline poured over the mixture. 3 grams of mercury were added as a catalyst. The mixture ?/as heated on an oil bath at 110-115* for over and hour. It was then washed with 100 cc, of N sulphuric acid, and 75 cc. of chloroform filtered and the chloroform extract evapor- - 17 atsd, Ths light brown viscous substance and some free alizarin resulted, but the relative amount had not increased. This residue gave the same tests as were applied to the similar sub- stance that had been isolated, and gave the sane results. A blank test was made of menthol glucoside which has been (33) successfully formed by this method. The yield in this case was quantitative, and the compound was easily crystallized. This compound would not have the complexity of a hydroxyanthraquinone glucoside, and for this reason would be more easily formed and crystallized. B Emodin Glucoside, The procedure followed was similar to that use in the case of alizarin. Five grams of acetobromoglucose were added to an absolute alcohol solution of 3.3 grains of emodin and 3.06 grams of potassium hydroxide. The mixture was allowed to stand for a week in a tightly stoppered flask, and then refluxed for an hour. The deep red solution still remained. The odor of ethyl acetate was evident when the flask was opened. The alcoholic solution was diluted and exactly neutralized with hydrochloric acid. The light brown precipitate settled out. This was filtered and dried upon a porous plats. After washing with ether to extract the free emodin and with water to extract any uncombined carbohydrate, the substance was hydrolysed with dilute sulphuric acid. The resulting solution gave no test for the presence of a carbohydrate. ,‘V ; ^ I '< ' ■”\ C' , ,.•• y. ■ ‘ -^rr) ..'■ >. '■•rrrT ,.t; 'v>- ■ ■' .-.- r , ' i' r- /’ . ^ . ■■ '* *• ‘ -t ». * ' * / i • /. • ^ 1 / •*• ' > „ i . ' f-% ., J- •k •. >. y ■' ' ■ “V> ;'■ ■ - •■' ' i - ..f '■ .4 * ■ .O i'.v • .. > '» ' '.r : .;• ■ > ■ ’M ■ '■ ■> 'L ■■ ... *. J. ^ . *v. . ^ ‘ W- V- t, . - ■r. . ■ > . • .. 1J, ■■ .•. •. ' '..,1 t.j '. • '>t /r; . ..:. -f/ - 18 EvTidently no combination had occurred between the emodin and the acato-bromoglucose. The use of the method with the shaking machine was then resorted to. Five grams of acetobromoglucose, 3.3 grams of emodin 2.06 grams of potassium hydroxide were added to 200 cc, of water and 200 cc. of ether. This mixture was placed in the bottle which was connected with the shaking machine. This was run inter- mittently for twenty-four hours. The ethereal layer was evap- orated. The dark powder which resulted was subjected to hydroly- sis with dilute sulphuric acid, and did not yield any test for the presence of carbohydrates. The dark powder gave no evidence of the combination of emodin and glucose. C EMODIN GLUCOSIDE (Anthra-rhamnoside) the procedure was similiar to that carried out with the alizarin and tetra-acetylbromoglucose, with however, the use of acetobromorharnnose in the place of the glucose derivative. Five grams of the acetobromorharnnose were added to an ab- solute alcohol solution of four graRis of emodin and 2.48 grams of potassium hydroxide. A deep red mixture was formed. This was allowed to stand at room temperature for one week, and then refluxed for two hours. The odor of ethyl acetate was apparent when the cork viras removed. A dark powder had precipitated out. This was filtered off and dried. It was then washed with ether and dried. It failed to give a melting point belov/ 300°C. and - 19 was insoluble in the organic solvents. Upon hydrolysis it did not yield any test for carbohydrate. This did not in any way ( 18 ) correspond to the product which was secured by Gunton, but upon analysis it was found that the product had been destroyed through too much refluxing. The same quantities were again mixed and added to an ab- solute alcohol solution, and permitted to stand for one week. This ms then refluxed for 45 minutes. The contents were poured into a beaker and permitted to evaporate at room temperature. The resulting mass was a light brovm powder. This was dissolved in a small quantity of water and exactly neutralized with hydro- chloric acid. A light brown precipitate settled out. This was filtered off, and dissolved in a mixture of alcohol and water. A slight portion did not dissolve, so this was filtered off. The solution was digested on the steam bath with the occasional addition of some distilled water. A light hrorni powder soon settled out. This was washed with v;ater and dried, then washed in ether. The ether extract v;as evaporated, and the residue gave a melting point for emodin. After complete drying the substance gave a melting point of 330°, although this was not sharp. A portion of this sample was intimately mixed with some natural frangulin and the resulting melting point was 315°. The substance was wahhed with water. V/hen the water gave no test for the presence of carbohydrate^ a sample was then subjected to hydrolysis with dilute sulphuric acid for three hours. The resulting solution gave positive tests for the - 30 - presence of a carbohydrate, altho all of the material did not hydrolyse readily. Extraction of the hydrolysed mixture v;ith ether gave pure emodin. Another test was made with the same amounts and the same procedure followed. The yield was the same as in the previous experiment. The amorphous powders of the two experiments were mixed together and attempts were made to secure a crystalline product through the use of alcohol, chloroform and acetone. The latter was used because it has been used as a crystallizing solvent for frangulin. The slow evaporation method and the use of the vacuum were resorted to, but the amorphous powder was always deposited when the solvent had avaporated. Although the color of the powder, and melting point point resembled frangulin, the solubility of the substance was not of the same class. Nothing crystalline was obtained. But from the properties found there seems to have been some combination of the glucose derivative and the emodin. - 31 V SU1'£MARY The synthesis of an alizarin gluooside was atteii^tsd by means of a potassium salt method with an acetyl derivative of glucose. Nothing of a glucosidic compound ms isolated from the result. By using the saurjematerial but by trying to effect the combination through shaking in an etheral solution another trial was made. This failed to yield any glucoside. The formation of a substance by heating the glucose derivative and alizarin in quinoline gave tests that a com- bination had taken place in the ratio of two molecules of sugar to one of alizarin. By means of the potassium salt method v;ith emodin and rhamnose a compound v/as formed which had similar melting point and color to the natural oc curing frangulin, but its solubility differed from the latter. - 33- VI BIBLIOGRAPHY (1) Robiqust and Colin - Annanles de Chemie (1837), 335 (2) Decaisne - J. prakt. Chem, (1838), 1^, 393 (3) Rochledsr - Ann. Chem. 346; _80, 321; 0^, 205. (4) Schunk - J. Chsm. Soc. (1860), 12, 316 (5) Stokes - J. Chem. Soc. (i860), 13, 319 (6) Schunk and Harchlewski - J. Chem. Soc (1893), _63, 969 (7) Lieberrnann and Bergami - Ber. Chem. Ges.(l887), 2241 (8) Perkin - J. Chem. Soc. (1897), H94 (9) Ivliiller and la Rue - Jahresber, (1857) 517. (10) Muller - J. Chem. Soc. (1911), 967. (11) Tutin and Clewer - J, Chem. Soc. ('1911 )_^, I, 946. (13) Jowett and Potter, J. Chem, Soc. _81, 1575 (13) Tutin - J. Chem. Soc. (1913), 103, 2006 (14) Bailsy - J. Ind. and Eng. Chem. (1914) ,_6, 320 (15) Binswanger - Ann. de Chem. u. Phar. 23.* ^56. (16) Faust - Ann. de Chem. u. Phar. 165 , 339 Kubly (17) .APharm. Zeitsch. F. Russl, V, part. 3. Gunton (18) ^hesis, University of 111. (1931) 0 (19) Colley Comp. rend. 70, 401 (30) Michael - Ber. d. deut. Chem. Ges, (1881), lA, 3097 (21) Schiff - Ann. 144, 19 (1886) (22) Druin - Bull. Soc. Chira. (ill), 13, 5. (1895) (33) Irvine - J. Chem. Soc. (1913) 103 . 41. - 33 (34) Ryan - Proc. Roy^ Irish Acad. (1903), 34, 379 (35) Ivlauthner - 2T. prakt. Chem. (1910), _83, 271 (36) Sal way - J. Chem. Soc. (1913), lOZ, 1033 (37) Schneider - Ber. (1914) 1356_1369; 3318-3334 (38) Fischer - Ber. (1893) ,16, 3938 Ber. (1895) ,38, 1145 Annalen . (1911 ) , 383, 68 (39) Walton - J.A.C.S. (1931) ,43,137 (30) Thorpe, Diet. Applied Chem. Vol. I, 79. (31) Dale, J. A.C.S, (1916) 38, 3187 (33) Fischer - Ber. 4_5, 3468 (1913) (33) Fischer - Ber. (1917), 50, 711