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The anthocyanin pigments are responsible for the red, blue, and purple color of most fruits and vegetables. This review covers the following aspects of anthocyanins: their chemical structure and the relation between chemical structure and color; the theories of their biogenesis and factors affecting their synthesis in plants; their distribution among fruits and vegetables; the chemical, physical, and biochemical factors affecting their degradation in fresh and processed food commodities; degradation schemes; ways and means for stabilizing these pigments in foods and methods for extracting, identifying, and quantifying their concentration in foods.

Summary Experiments were conducted to determine whether certified coal-tar dye solutions could be used to color diluted semen in order to reduce errors in its handling. Red, green, brown, and purple color preparations were tested, under laboratory and field conditions. Spermatozoa in diluted semen colored at the rate of one drop of the basic red, green, brown, and purple dye solutions for each 10 ml. of diluter maintained their motility as well as those in the uncolored controls. In a field study, when the same dyes were used at a lower concentration, no significant differences in fertility were found between the colored and uncolored semen samples. This investigation involved 2,995 inseminations and an average of 59.9 cows were inseminated per semen sample. The results obtained demonstrate that the coal-tar color preparations described can be safely used as a practical means of coloring diluted bull semen.

A spectrophotometric determination of osmium has been developed, based on the purple color (absorption maximum at 515 mμ) formed by reaction of osmium with quinisatin oxime in buffered solution of dimethyl formamide and methanol. The absorbances are reproducible, and the system conforms to Beer's law. The method compares favorably in sensitivity with existing methods for osmium. The optimum concentration range (for 1 cm optical path) is about 2 to 10 p.p.m. of osmium. Although the maximum color develops slowly, it is stable for 7 days or longer. Several elements, notably iron, cobalt, and ruthenium, interfere, so that separation, is necessary. A reaction ratio of 1:2 for osmium and quinisatin oxime was clearly indicated; some evidence was also obtained for the presence of higher complexes.

THE coal tar dye industry of Europe is but 88 years of age. That of the United States is eight or ten years younger. How many of us who are active in this field know much about the worries and woes experienced by the pioneers of this industry? Of course, we have been told that in 1856 Perkin, while seeking to synthesize quinine, obtained a product soluble in alcohol with a purple color. He found that this solution would dye silk and wool. The fact that his new product gave a shade not obtainable from any one natural product and its ease of application led to its immediate use in the textile industry. Perkin was granted a British patent aftersome difficulty because he was a minor. But the reign of Perkin's mauve was cut short by the discovery of better dyes—fuchsine, benzaldehyde green, methyl violet, rosaniline blues—which followed quite soon. It was in the attempts ...

The absorption spectra of visual purple solutions extracted by various means were measured with a sensitive photoelectric spectrophotometer and compared with the classical visual purple absorption spectrum. Hardening the retinas in alum before extraction yielded visual purple solutions of much higher light transmission in the blue and violet, probably because of the removal of light-dispersing substances. Re-extraction indicated that visual purple is more soluble in the extractive than are the other colored retinal components. However, the concentration of the extractive did not affect the color purity of the extraction but did influence the keeping power. This suggests a chemical combination between the extractive and visual purple. The pH of the extractive affected the color purity of the resulting solution. Over the pH range from 5.5 to 10.0, the visual purple color purity was greatest at the low pH. Temperature during extraction was also effective, the color purity being greater the higher the temperature, up to 40°C. Drying and subsequent re-dissolving of visual purple solutions extracted with digitalin freed the solution of some protein impurities and increased its keeping power. Dialysis against distilled water seemed to precipitate visual purple from solution irreversibly. None of the treatments described improved the symmetry of the unbleached visual purple absorption spectrum sufficiently for it to resemble the classical absorption spectrum. Therefore it is very likely that the classical absorption spectrum is that of the light-sensitive group only and that the absorption spectra of our purest unbleached visual purple solutions represent the molecule as a whole.

SummaryIt has been shown that deoxyhexoses and hexals react with the Dische diphenylamine reagent in a characteristic manner. No other structures except sialic acid and related compounds have been found to react in the same fashion. A deoxyhexose structure for sialic acid has been proposed by Gottschalk. The color given by sialic acid when heated with the reagent is therefore accounted for by the presence of the deoxyhexose. Since sialic acid is considered to be a common constituent of the glycoproteins (mucoproterns), the color given by these substances and serum when heated with the Dische reagent appears to be due to the deoxyhexose present in sialic acid.

There exist certain groups of bacteria which possess a peculiar purple color. This color ranges from a pale bluish pink to a deep crimson, almost like Ruthenium red. The bacteria concerned may be grouped according to their physiological behavior into four distinct classes:The almost algal Chromatium, the pediococcoid Thiopedia, Spirillae, Bacillae, and Cocci all possess the pigment purple color.There is therefore no a priori evidence for the identity of the pigments.Classes I and II, the true Rhodobacteria, seem to have identical pigments (Molisch). One of them is red, probably a carotinoid, bacterio-erythrin, the other is green, soluble in absolute alcohol and is called bacteriochlorin∗. The combination of both pigments is called bacteriopurpurin. Bacteriochlorin has a marked narrow absorption-band with an axis near the sodium lines D.Bacterio-erythrin is characterized by two distinct absorption bands in the green and bluegreen.An absolute alcohol extract of Thiopolycoccus yielded a green solution with a b...

It was ascertained that the species from which Grimm alfalfa presumably originated, viz.; Medicago sativa and M. falcata, may freely exchange genetic material without evidence of a sterility barrier. Consequently a polyhaploid obtained of Grimm may be considered as comparable to natural diploids.The polyhaploid showed some impaired morphological and physiological characters and pronounced meiotic abnormalities. The single genome (x = 8) of the polyhaploid was found to be almost non-functional. Inheritance of purple color indicated a potential autotetraploid mode of transmission of characters.The polyhaploid was raised back to the tetraploid chromosome level by chromosome doubling and compared to its original and to Grimm. The somatically chromosome-doubled counterpart was found to be a close replica of the original polyhaploid. An assumption that an accumulation of detrimental recessive genes may remain latent at the tetraploid level, and may be expressed upon later reduction to half of the genic variability as in the polyhaploid and its somatically chromosome-doubled derivative, is advanced to explain the observed phenomena.Phylogenetic, breeding, and culture-historical aspects of the results are discussed.

A new method for colorimetric determination of Δ 4 -3-ketosteroids with p-nitrophenylhydrazine was studied and the standard procedure for the concentration of 10 μg–50 μg of steroid samples was established. The principle of this method is based on the observation that the hydrazone formed with p-nitrophenylhydrazine produces astable reddish purple color which has an absorption maximum at 540 mμ in an alkaline solution of dimethylformami de. The present method is specific forΔ 4 -3-ketosteroids and gives a maximum absorption in longer wave-length regions with a markedly higher intensity than the other methods.

Chymochromic pigments in twenty-five color forms of common portulaca dividing into eleven color groups and their F1 hybrids were studied by paper-chromatographic and spectrophotometric experiments.Ten pigments of betacyanins (Bc1 to Bc5) and betaxanthins (Bx1 to Bx5) were chromatographically separated in various color forms of garden portulaca. Most of the flower colors were estimated by qualitative and quantitative differences of chymochromic pigments.In general, the purple components, Bc3 and Bc4, predominantly appeared in most of F1 hybrids, while the yellow components, Bx1 and Bx2, did not appear in F1 hybrids. Therefore, betacyanin were, in general, dominant over betaxanthin.On the other hand, the higher content of betacyanin in purple color form is dominant to the lower content of betacyanin in pink form, and the higher content of betaxanthin in yellow orange form is recessive to the lower content of betaxanthin in pink form in F1 hybrids. In some F1 hybrids, however, the pigment content is nearly intermediate between the contents of both parents. White color form containing neither betacyanin nor betaxanthin is recessive to all the colored forms examined.

There are many methods of preparing and staining skin scrapings for the examination for the presence of fungi. Probably the most widely used method is the simple KOH method suggested by C.W. Dodge. This method, however, requires a high degree of skill and often misreading is experienced. In order to elevate the problems evolved I have developed a new method which utilized, KOH, CuSO4.5H2O and Eosin Y, with the following results. The body of the fungi appears as purple-pink to purple in color, while tissue appears pink in color. The reaction is a biochemical reaction. As the tissue is dissolved the CuSO4 in converted to Cu(OH)2 which in turn reacts with sugars or organic exalic acid in the body of the fungi, the end point being complex salt, which shows as a blue color, however this reaction is very weak and because of this Eosin Y is added to enhance the reaction resulting in the purple color, which is very easy to observe microscopicly. Microscopicly the observer is able to discern different color reactions in the various structures of the fungi. For example : the spore stains a deeper color than the mycelium, also one can observe spore formation in the mycelium. I have studied this method in twelve different cases of mycotic infections, using the KOH method and the culture method along with my new technique. In all cases using the new method proved to be 100% accurate while the KOH method was only 50% accurate. This method then is simple, less time consuming with a higher degree of accuracy, than the old KOH method and can very easily be utilized clinically for the identification of mycotic infections.

A new method has been developed for the determination of trace quantities of formaldehyde and appears to be superior to existing methods. The procedure is based on a modification of Schiff’s test for aldehydes. A mixture of dichlorosulfitomercurate II complex and acid bleached pararosaniline hydrochloride is used as the reagent. In the presence of formaldehyde, a purple color is produced. The method is highly sensitive to formaldehyde and acetaldehyde, simple and does not require concentrated acids. When applied to air pollution studies, the method is virtually free of interferences from higher aldehydes. The paper describes the application of this method to spot sampling of the atmosphere and to continuous atmospheric analysis.

Hog bile salts when mixed with sulfuric acid and benzaldehyde give a purple color, but this test is unsuitable for the detection of hog bile in mixtures with ox or sheep bile salts, which produce a brown color obscuring the purple color. A quantitative separation of hog bile from sheep or ox bile is described. The principle involved depends upon the action of hydrochloric acid which precipitates hog bile from solution in the form of a gummy mass, whereas with ox or sheep bile only slight precipitates are formed under the conditions of the test described.

The extremely high incidence of salicylate intoxication makes it desirable to have a screening test available. Such a procedure should be simple and rapid enough to be used routinely on all admission and emergency cases since salicylate intoxication may not be suspected. This report describes studies with a stick test used on urine and serum. Test results agree well with quantitative measurements. Specimens tested included urine and serum from dogs and human beings after experimental administration of aspirin as well as samples from cases of salicylate intoxication or high therapeutic salicylate levels. The test strip develops an immediate brownish purple color with as little as 20 mg. per cent free salicylate. Data are presented to show that reliable results are obtained with the test even by inexperienced individuals.

A colorimetric method in which sodium beta-naphthoquinone-4-sulfonate (purified) is reacted with digitoxin in alkaline solution to form a purple color is proposed for the determination of digitoxin. The purple color quickly reaches a maximum and fades, but the addition of acetic acid at the time of maximum development changes the color to yellow and stabilizes it. The procedure involves no special equipment and may be adapted to any colorimeter or spectrophotometer by appropriate changes in the digitoxin concentration to suit the particular instrument. Data and tables are given to show results obtained with various samples of digitoxin and with several lots of tablets.

Dear Sir: —About May 1 I was called to see Mr. F., aged 78, feeble and quite fleshy, who had a large abscess over the right scapula. It was opened and a large quantity of pus evacuated. The skin over it was of a dark purple color, and sloughing seemed imminent, but evacuation and drainage caused it to heal without refilling. Prompt recovery took place. His wife nursed him and dressed the abscess, a 10 per cent. solution of carbolic acid being used. A week after the abscess was opened Mrs. F. was taken with facial erysipelas of a severe type, which ran a course of about 14 days. Towards the last the disease attacked the right leg just above the ankle; an abscess formed and pus was evacuated, and recovery followed. The origin of the cold abscess of Mr. F. could not be ascertained; there was no history except

A technique is presented for the separation in the field of dolomitic limestones from high calcium limestones. The procedure requires an application of two solutions on a fresh rock surface. The rate at which a blue color is precipitated will separate dolomitic limestones from other non-magnesium carbonates. A purple color indicates a lack of magnesia.

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Schwenk and Hildebrandt1 described the isolation from the urine of pregnant mares of a new compound of high estrogenic potency. This substance, designated by them δ- follicular hormone, melted at 209°, gave a characteristic purple color when coupled with p-nitro-diazobenzene and showed a gold yellow fluorescence in concentrated sulfuric acid solution. Analysis of the compound itself and of its mono-benzoate indicated the composition C18H22O2. Treatment with ketone reagents failed to give characteristic derivatives.Another batch of pregnant mare's urine has now been worked up in the laboratories of the Schering Corporation (Bloomfield, N. J.). The compound present in largest amount in the crude fraction containing the phenol-alcohols is the above δ-follicular hormone. Analysis of the present preparation gave figures agreeing better with C18H24O2 than with C18H22O2. The preparation of a di-p-nitro-benzoate (m.p. 260° uncorr.) leaves no doubt that both oxygen atoms are present in the form of hydroxyl groups....

In a rapid colorimetric method for the determination of aconitic acid in sorgo juice, the acid is extracted from clarified starch-free juice with 2-butanone after lowering the juice pH to 1.3. One extraction re- layer, produce a purple colour which is read on a moves 99% of the aconitic acid. Othu organic acids, at the level found in sorgo juice, do not interfere with color development. Acetic anhydride and ridine, when added to an aliquot of the 2-butanone layer, produce a purple color which is read on a spectrophotorneter at 550 m.

For years we have puzzled over the meaning of a slight increase in the value of serum bilirubin, with or without slight jaundice, barely detectable either by the patient or by the trained physician. Naturally we have suspected that in at least some of these cases the liver has suffered an injury leading to dysfunction, but we could not be sure. In the hope of throwing light on the problem, we have analyzed the data in all such cases encountered at the Mayo Clinic from 1930 to 1931. It will be remembered that in most laboratories today the concentration of serum bilirubin is classified and measured by van den Bergh's technic. At the clinic, Lepehne's ring test is first applied to determine the type of bilirubin reaction. If, after the diazo-reagent has been added, a purple color appears within one minute, the reaction is said to be "direct;" if the

March 19, 1888, Mrs. Esther Smith, aet. 71 years, widow, consulted me on account of an eye trouble. She stated that her vision had been somewhat obscured in her left eye for a few days, and that at the time of her visit she was quite unable to distinguish objects on account of everything being clothed in a deep purple color. Upon examination I found R.E.V. =+ 1D. V. =L. E. V. = perception of form. Ophthalmoscopic examination showed a large number of circular red spots in all parts of the fundus, macula especially presenting the appearance as seen in embolism of central artery of retina, except the haemorrhage was not defined, but shaded off into other haemorrhages. Tension normal. Patient well preserved, and gave no evidence of heart changes or vascular degenerations which I could detect. Fundus and vitreous hazy in certain strata. I prescribed sol. muriate

Sjoerdsma and his associates have described a simple qualitative urine test for the detection of increased amounts of the serotonin metabolite, 5-hydroxyindoleacetic acid (5-HIAA).1This test is based on the development of a purple color, specific for 5-hydrooxyindoles, on the addition of 1-nitroso-2-naphthol and nitrous acid. In normal individuals 5-hydroxyindoleacetic acid is excreted in the urine in amounts varying from 2 to 9 mg. per day, while in six patients with metastatic carcinoid (argentaffinoma) its excretion was found to vary from 76 to 580 mg. per day.2These authors have not encountered other clinical conditions associated with an elevated excretion of 5-hydroxyindoleacetic acid and feel that the test is specific for metastatic carcinoid. Due to the widespread interest in the action and metabolism of serotonin, it was felt that it would be interesting to perform this test on a large number of patients in an effort to determine

In connection with the recent article by Shaw and coworkers (Pediatrics, 23:485, March, 1959) on the possibility of neurologic complications following the use of phenothiazine tranquilizers, attention is called to a simple laboratory test, first pointed out by Fellman (J. Nerv. & Ment. Dis., 123:575, 1956) and later popularized by the Forrests (Am. J. Psych., 113:931, 1957) which—especially in the absence of a good history—may help to establish the diagnosis. A few drops of the urine of a patient who has taken one of the phenothiazides will give a red to purple color when mixed with ferric chloride solution (usually stocked as a 10% solution). A similar color reaction is obtained with Phenistix®, a paper strip impregnated with ferric chloride ions, marketed by the Ames Company, Inc. for the testing of urines to detect phenylketonuria.