Hematoxylin Substitutes: Fluorone Black and Methyl Fluorone Black (9-Phenyl- and 9-Methyl-2, 3, 7-Trihydroxy-6-Fluorone) as Metachrome Iron Alum Mordant Dyes

The phenyl and methyl trihydroxyfluorones, hitherto used histologically only in the rather difficult and unreliable Turchini tecbnics for discriminating deoxyribonucleic from ribonucleic acid, find a new use as iron mordant metachrome dyes which act as nuclear stains. Nuclear staining is unaffected by acid extraction of nudeic acids, as with hematoxylin lakes.

The two dyes, named by Liebermann and Lindenbanm 9-phenyl-2, 3, 7-trihydroxy-6-fluorone and 9-methyl-2, 3, 7-trihydroxy-6-Ruorone, have also acquired (illustrating with the phenyl homolog) longer chemical names of the form 2, 6, 7-trihydroxy-9-phenylisoxanthene-3-one (Eastman). Aldrich and Pfalz-Bauer adhere to the Liebermann-Lindenbaum nomenclature. The trivial name fluorone black is proposed for the phenyl homolog and methyl fluorone black for the methyl homolog.

The iron lake of fluorone black appears to be a useful substitute for iron hematoxylin, methyl fluorone black less useful. Neither dye has the diverse capability of hematoxylin.

Aided by a contract from the National Cancer Institute NO-1-CB-43912     

Nuclear stains with soluble metachrome metal mordant dye lakes. The effect of chemical endgroup blocking reactions and the artificial introduction of acid groups into tissues.

Following our study on the effect of deoxyribonucleic acid (DNA) extraction on nuclear staining with soluble metal mordant dye lakes covering 29 dye lakes we chose a series of lakes representing the three groups: (1) readily prevented by DNA removal, (2) weakened by DNA extraction but not prevented, (3) unaffected by DNA removal, for application of other endgroup blockade reactions. The lakes selected were alum and iron hematoxylins, iron alum and ferrous sulfate galleins, Fe2+ gallo blue E, iron alum celestin blue B, iron alum fluorone black and the phenocyanin TC-FeSO4 sequence. Azure A with and without an eosin B neutral stain, was used as a simple cationic (and anionic) dye control. Methylation was less effective than with simple cationic dyes, but did weaken celestin blue, gallo blue E and phenocyanin Fe2+ nuclear stains. These dyes also demonstrate other acid groups: acid mucins, cartilage matrix, mast cells, central nervous corpora amylacea and artificially introduced carboxyl, sulfuric and sulfonic acid groups. Alum hematoxylin stained cartilage weakly and demonstrated sulfation and sulfonation sites. The iron galleins, iron fluorone black and acid iron hematoxylin do not. A pH 4 iron alum hematoxylin gave no staining of these sites; an alum hematoxylin acidified with 1% 12 N HCl gave weaker results. Deamination prevented eosin and orange G counterstains but did not impair nuclear stains with any of the mordant dye lakes. The simple acetylations likewise did not alter mordant dye nuclear staining, the Skraup reagent gave its usual sulfation effect on other tissue elements, but did not alter nuclear stains by mordant dyes. The mordant dyes do not bind to periodic acid engendered aldehyde sites and p-toluidine/acetic acid and borohydride aldehyde blockades did not alter mordant dye lake nuclear staining. Nitration by tetranitromethane, which blocks azo coupling of tyrosine residues, did not alter nuclear staining by the mordant dye lakes. Benzil at pH 13, which prevents the beta-naphthoquinone-4-Na sulfonate (NQS) arginine reaction and the Fullmer reaction of basic nucleoprotein, did not affect iron gallein, iron or alum hematoxylin stains of nuclei or lingual keratohyalin.     

Nuclear stains with soluble metachrome metal mordant dye lakes

Summary Following our study on the effect of deoxyribonucleic acid (DNA) extraction on nuclear staining with soluble metal mordant dye lakes covering 29 dye lakes we chose a series of lakes representing the three groups: (1) readily prevented by DNA removal, (2) weakened by DNA extraction but not prevented, (3) unaffected by DNA removal, for application of other endgroup blockade reactions. The lakes selected were alum and iron hematoxylins, iron alum and ferrous sulfate galleins, Fe²⁺ gallo blue E, iron alum celestin blue B, iron alum fluorone black and the phenocyanin TC-FeSO₄ sequence. Azure A with and without an eosin B neutral stain, was used as a simple cationic (and anionic) dye control.Methylation was less effective than with simple cationic dyes, but did weaken celestin blue, gallo blue E and phenocyanin Fe²⁺ nuclear stains. These dyes also demonstrate other acid groups: acid mucins, cartilage matrix, mast cells, central nervous corpora amylacea and artificially introduced carboxyl, sulfuric and sulfonic acid groups. Alum hematoxylin stained cartilage weakly and demonstrated sulfation and sulfonation sites. The iron galleins, iron fluorone black and acid iron hematoxylin do not. A pH 4 iron alum hematoxylin gave no staining of these sites; an alum hematoxylin acidified with 1% 12 N HCl gave weaker results.Deamination prevented eosin and orange G counterstains but did not impair nuclear stains with any of the mordant dye lakes. The simple acetylations likewise did not alter mordant dye nuclear staining, the Skraup reagent gave its usual sulfation effect on other tissue elements, but did not alter nuclear stains by mordant dyes.The mordant dyes do not bind to periodic acid engendered aldehyde sites and p-toluidine/acetic acid and borohydride aldehyde blockades did not alter mordant dye lake nuclear staining. Nitration by tetranitromethane, which blocks azo coupling of tyrosine residues, did not alter nuclear staining by the mordant dye lakes¹. Benzil at pH 13, which prevents the -naphthoquinone-4-Na sulfonate (NQS) arginine reaction and the Fullmer reaction of basic nucleoprotein, did not affect iron gallein, iron or alum hematoxylin stains of nuclei or lingual keratohyalin.Assisted by Contract Nol-CB-43912 National Cancer Institute     

Hematoxylin substitutes: a survey of mordant dyes tested and consideration of the relation of their structure to performance as nuclear stains.

In the search for hematoxylin substitutes 26 dyes were more or less extensively tested for performance as nuclear stains, usually in combination with aluminum, chronic, ferrous and ferric salts. Reports from the literature on hematoxylin substitutes were also considered, and efforts were made to obtain samples of favorably reported dyes and test them. The reports on anthocyanins include isolated reports on several berry juices and a considerable number of studies on Sambucus niger and Vaccinium myrtillus. None of these have so far been tested by us. Otherwise favorable reports have appeared on eleven synthetic dyes and on carmine, brazilin, and hematin. Except for one of the synthetics, naphthazarin, which is no longer fractured, we had samples of all of these. In addition, more or less unsuccessful trials were made on twelve dyestuffs, some of which were new syntheses designed to combine chelating capacity with nucleophilia. Following Fyg's report of blue nuclear staining with chrome alum carmine, trial was made to change the red nuclear stain of kernechtrot by altering the metal mordant. The most successful dyes were phenocyanin TC, gallein, fluorone black, alizarin cyanin BB and alizarin blue S. Celestin blue B with an iron mordant is quite successful if properly handled to prevent gelling of solutions.     

Hematoxylin Substitutes: A Survey of Mordant Dyes Tested and Consideration of the Relation of Their Structure to Performance as Nuclear Stains

In the search for hematoxylin substitutes 26 dyes were more or less extensively tested for performance as nuclear stains, usually in combination with aluminum, chromic, ferrous and ferric salts. Reports from the literature on hematoxylin substitutes were also considered, and efforts were made to obtain samples of favorably reported dyes and test them. The reports on anthocyanins include isolated reports on several berry juices and a considerable number of studies on Sambucus niger and Vaccinium mytillus. None of these have so far been tested by us. Otherwise favorable reports have appeared on eleven synthetic dyes and on carmine, brazilin, and hematein. Except for one of the synthetics, naphthazarin, which is no longer manufactured, we had samples of all of these. In addition, more or less unsuccessful trials were made on twelve dyestuffs, some of which were new syntheses designed to combine chelating capacity with nucleophilia. Following Fyg's report of blue nuclear staining with chrome alum carmine, trial was made to change the red nuclear stain of kernechtrot by altering the metal mordant.

The most successful dyes were phenocyanin TC, gallein, fluorone black, alizarin cyanin BB and alizarin blue S. Celestin blue B with an iron mordant is quite successful if properly handled to prevent gelling of solutions.     

Metallic Lakes of the oxazines (Gallamin Blue, Gallocyanin and Coelestin Blue) as Nuclear Stain Substitutes for Hematoxylin

Becher's investigations upon the soluble metallic lakes of the oxazines have been re-investigated, extended and results described. Gallamin blue, gallocyanin and coelestin blue in combination with ferric ammonium sulfate gave the best results. The dyes are dissolved in a five per cent aqueous solution of ferric ammonium sulfate. The solution is boiled for 2-3 minutes, cooled, filtered and ready for immediate use. The iron lakes of these dyes stain nuclei excellently giving a deep blue or blue black in 3-5 minutes. No differentiation with acid is required. Coelestin blue gives the most stable solution and is recommended as a routine nuclear stain. The protoplasm remains practically colorless and counter-staining with acid dyes such as ethyl-eosin, orange G, or fuchsin gives pictures which cannot be distinguished from a good hematoxylin stain.

Counter-staining with van Gieson solution is also possible. Benda's modification of the van Gieson solution is recommended. Staining of fat with Sudan, scarlet red, etc., does not interfere with nuclear staining by these dyes.

As applied to the central nervous system these dyes are far superior to hematoxylin. Ganglion and glia cells are as excellently stained as with thionin.

The most widely used fixatives, namely formaldehyde, Mueller-formaldehyde, Zenker's and alcohol, give equally as good results. The nature of the staining process is briefly discussed and a prospectus offered.     

Metallic Lakes of the oxazines (Gallamin Blue,Gallocyanin and Coelestin Blue) as Nuclear Stain Substitutes for Hematoxylin

Becher's investigations upon the soluble metallic lakes of the oxazines have been re-investigated, extended and results described. Gallamin blue, gallocyanin and coelestin blue in combination with ferric ammonium sulfate gave the best results. The dyes are dissolved in a five per cent aqueous solution of ferric ammonium sulfate. The solution is boiled for 2–3 minutes, cooled, filtered and ready for immediate use. The iron lakes of these dyes stain nuclei excellently giving a deep blue or blue black in 3–5 minutes. No differentiation with acid is required. Coelestin blue gives the most stable solution and is recommended as a routine nuclear stain. The protoplasm remains practically colorless and counter-staining with acid dyes such as ethyl-eosin, orange G, or fuchsin gives pictures which cannot be distinguished from a good hematoxylin stain.

Counter-staining with van Gieson solution is also possible. Benda's modification of the van Gieson solution is recommended. Staining of fat with Sudan, scarlet red, etc., does not interfere with nuclear staining by these dyes.

As applied to the central nervous system these dyes are far superior to hematoxylin. Ganglion and glia cells are as excellently stained as with thionin.

The most widely used fixatives, namely formaldehyde, Mueller-formaldehyde, Zenker's and alcohol, give equally as good results. The nature of the staining process is briefly discussed and a prospectus offered.     

Fluorone dyes have binding sites on both cytoplasmic and extracellular domains of Na,K-ATPase

Combination of fluorescence techniques and molecular docking was used to monitor interaction of Na,K-ATPase and its large cytoplasmic loop connecting fourth and fifth transmembrane helices (C45) with fluorone dyes (i.e. eosin Y, 5(6)-carboxyeosin, rose bengal, fluorescein, and erythrosine B). Our data suggested that there are at least two binding sites for all used fluorone dyes, except of 5(6)-carboxyeosin. The first binding site is located on C45 loop, and it is sensitive to the presence of nucleotide. The other site is located on the extracellular part of the enzyme, and it is sensitive to the presence of Na⁺ or K⁺ ions. The molecular docking revealed that in the open conformation of C45 loop (which is obtained in the presence of ATP) all used fluorone dyes occupy position directly inside the ATP-binding pocket, while in the closed conformation (i.e. in the absence of any ligand) they are located only near the ATP-binding site depending on their different sizes. On the extracellular part of the protein, the molecular docking predicts two possible binding sites with similar binding energy near Asp897(α) or Gln69(β). The former was identified as a part of interaction site between α- and β-subunits, the latter is in contact with conserved FXYD sequence of the γ-subunit. Our findings provide structural explanation for numerous older studies, which were performed with fluorone dyes before the high-resolution structures were known. Further, fluorone dyes seem to be good probes for monitoring of intersubunit interactions influenced by Na⁺ and K⁺ binding.     

The Use of Buffered Solutions in Staining: Theory and Practice

The importance of pH in staining tissue is emphasized. The effect of pH upon the selectivity and intensity of staining with iron hematoxylin, malachite green, and eosin Y is considered. Many difficulties may be avoided by staining in the higher alcohols and directions are given for the preparation of buffer solutions from pH 1.2-8 in alcohol. The concentration of stains, time of staining, and order of staining are discussed for progressive and regressive staining. At pH 8 in 95% alcohol very few tissues stain with malachite green at a concentration of 1/1000 saturated. At pH 6 most cytoplasmic elements stain with malachite green at a concentration of 1/1000 saturated or with eosin Y at 1/250 saturated. As the pH is lowered more tissue elements stain until the nucleus is completely stained. This behavior is in accord with the theory of chemical combination of dyes with proteins, which states that proteins combine with basic dyes on the basic side of their isoelectric points and with acid dyes on the acid side of their isoelectric points. With hematoxylin stain the pH range is much shorter. A satisfactory hematoxylin stain is composed of 0.1% hematoxylin, 0.1% FeCl₃, and HCl to bring the pH to 1.2-1.6 in 80% alcohol. With this stain, which may be used immediately, the nuclei of most tissues begin to stain at pH 1.2 and much of the cytoplasm will be stained if the pH is raised to 1.4. The shortness of this effective pH range is thought to be due to the dissociation of the hematoxylin-iron-protein complex. The use of different dyes successively at different pH values, such as hematoxylin at 1.3, malachite green at 8, and eosin at 6, permits better differentiation of the tissue elements, and intelligent variations in the staining technic.     

Vanadium-catalyzed transformation of 13(S)-hydroperoxy-9(Z), 11(E)-octadecadienoic acid: Structural studies on epoxy alcohols and trihydroxy acids

Treatment of methyl 13(S)-hydroperoxy-9(Z), 11(E)-octadecadienoate with vanadium oxyacetylacetonate led to the formation of two diastereometric α,β-epoxy alcohols, i.e. methyl 11(R), 12(R)-epoxy-13(S)-hydroxy-9(Z)-octadecenoate and methyl 11(S), 12(S)-epoxy-13(S)-hydroxy-9(Z)-octadecenoate. The epoxy alcohols underwent spontaneous hydrolysis into isomeric trihydroxyesters. The first mentioned epoxy alcohol afforded methyl 9(R), 12(S), 13(S)- and methyl 9(S), 12(S), 13(S)-trihydroxy-10(E)-octadecenoates as major hydrolysis products whereas the latter epoxy alcohol afforded methyl 9(R), 12(R), 13(S)- and methyl 9(S), 12(R)-13(S)-trihydroxy-10(E)-octadecenoates as major compounds. Smaller amounts of diastereomeric methyl 11,12,13-trihydroxy-9-octadecenoates were also formed from both epoxy alcohols. The vanadium-catalyzed conversion of 13(S)-hydroperoxy-9(Z),11(E)-octadecadienoic acid (13(S)HPOD) (methyl ester) into α,β-epoxy alcohols and their further conversion into trihydroxy derivatives offers a model system for similar transformations of certain poly-unsaturated fatty acids recently described in the fungus, Saprolegnia parasitica.     

ω-Hydroxymodin, a major hepatic metabolite of emodin in various animals and its mutagenic activity

The hepatic microsomes derived from various animal species transformed emodin (1,3,8-trihydroxy-6-methylanthraquinone), and anthraquinoid pigment present in fungal metabolites and a constituent of plant medicines, into an unidentified anthraquinone h, along with 2-hydroxy-, 4-hydroxy- and 7-hydroxyemodins. TLC, UV, MS and NMR clarified this unidentified major metabolite as ω-hydroxy-emodin (1,3,8-trihydroxy-6-hydroxymethylanthraquinone). Among 7 animal species, the highest activity to produce this ω-hydroxyemodin was observed in the hepatic microsomes of guinea pig and rat, followed by mouse and rabbit. The microsomal activity to convert emodin into ω-hydroxyemodin was accelerated by the pretreatment of animals with phenobarbital, and inhibited by SKF 525A. The microsomal hydroxylation reactions of the methyl residue and the anthraquinoid nucleus of emodin were presumed to be catalyzed regiospecifically by multiple forms of cytochrome P-450.

ω-Hydroxyemodin was not mutagenic to Salmonella typhimurium in the absence of S9, but exhibited mutagenicity in the presence of an activating system. This genotoxic potential was comparable to 2-hydroxyemodin, a direct-acting mutagen.     

Modified Whipf's Polychrome: A Connective Tissue Stain with Special Application for Demonstrating Leishmania

A polychrome stain procedure was developed to demonstrate amastigotes of the protozoan parasite Leishmania braziliensis as well as cytoplasmic and other tissue components in cutaneous lesions of infected animals. The procedure is as follows: stain nuclei for 10 minutes with an iron hematoxylin containing 0.5% hematoxylin and 0.75% ferric ammonium sulfate dissolved in 1:1 0.6 N H₂SO₄:95% ethanol; rinse 4 minutes in distilled water. Cytoplasmic staining is achieved by exposing tissues for 10 minutes to a solution containing 0.25% Biebrich scarlet, 0.45% orange G, 0.5% phosphomolybdic acid and 0.5% phosphotungstic acid in 1% aqueous acetic acid. These first two solutions are modified from Whipf's polychrome stain. Sections are differentiated for 10 seconds in 50% ethanol, rinsed in water, stained 3 minutes in 0.1% aniline blue WS in saturated aqueous picric acid, rinsed in water and differentiated for 1 minute in absolute ethanol containing 0.05% acetic acid. Mordanting overnight in 6% picric acid in 95% ethanol produced optimal results.

This procedure was applied to sectioned material from experimental animals with various protozoa. Trypanosoma cruzi, Besnoitia Jellisoni, Toxoplasma gondii and especially Leishmania braziliensis were well demonstrated. Combining cytoplasmic dyes and phosphomolybdic-phosphotungstic acids into one solution afforded differential staining of tissues by Biebrich scarlet and orange G; connective tissues were stained by this solution. Substantially improved definition of connective tissues resulted after counterstaining. This procedure differs from the Massou sequence in which connective tissues are first stained by cytoplasmic dyes along with other tissues and then destained prior to specific counter-staining. in comparing dyes structurally related to Biebrich scarlet, it was found that Crocein scarlet MOO, but not Poncenu S, was an acceptable substitute. Sirius supra blue GL and Sirius red FSBA were not useful as replacements for aniline blue WS in this procedure.     

Thin layer chromatography of commercial samples of amido black 10B

The tannic acid-phosphomolybdic acid-amido black (TPA) stain has been used primarily for staining hemoglobin. That different dye lots of amido black cause variable staining is documented in the literature. Nine commercial samples of amido black were investigated using thin layer chromatography; all of these dyes contained colored contaminants. Separation of contaminants was achieved using silica gel thin layer chromatography and a solvent system of 95% ethanol:90% phenol:concentrated NH4OH, 12:9:3. TPA staining of red blood cells was improved by using purified amido black.     

Synthesis of CMP-9'-modified-sialic acids as donor substrate analogues for mammalian and bacterial sialyltransferases

Cytidine-5'-monophospho-sialic acid (CMP-Neu5Ac) derivatives bearing a phenyl group in which the tether length between the phenyl group and the 9-position of Neu5Ac varied were synthesized and evaluated as substrates for sialyltransferases. In the synthesis of the compounds, a coupling reaction between methyl 5-acetamido-4,7,8-tri-O-acetyl-9-azido-3,5,9-trideoxy-beta-D-glycero-D-galacto-2-nonulopyranosonate and 2-cyanoethyl 2',3'-O,N4, triacetylcytidine-5'-yl N,N-diisopropylphosphoramidite was carried out and the phosphite derivative thus obtained was oxidized and then deprotected to yield CMP-9'-azido-Neu5Ac. Modification of the 9-amino group prepared by reduction of the azido groups was performed by the use of several phenyl-substituted alkylcarboxylic acid derivatives. Using these CMP-9'-modified-Neu5Ac analogues bearing the phenyl-substituted alkyl-amide group, sialyltransferase assays were performed with both rat liver alpha-(2-->6)-sialyltransferase and Photobacterium alpha-(2-->6)-sialyltransferase. These 9-modified analogues could be transferred to disaccharide acceptors, and a practical enzymatic synthesis using CMP-9'-modified-Neu5Ac yielded sialoside analogues and sialylglycoproteins in good yield. These experiments demonstrate that the Photobacterium sialyltransferase can be used in the synthesis of sialoside analogues having a large substituent at the 9-position of Neu5Ac.     

11, 15, 19-trihydroxy-9-ketoprost-13-enoic acid and 11, 15, 19-trihydroxy-9-ketoprosta-5, 13-dienoic acid in human seminal fluid.

Two novel prostaglandins (PG) have been found in human seminal fluid which had been frozen immediately after collection. They were characterized by combined gas-liquid chromatography-mass spectrometry of various derivatives as 19-hydroxy prostaglandin E1 (11, 15, 19-trihydroxy-9-ketoprost-13-enoic acid) and 19-hydroxy prostaglandin E2 (11, 15, 19-trihydroxy-9-ketoprosta-5, 13-dienoic acid). They were present in three to five times the quantity of prostaglandins E1 and E2. Incubation of seminal fluid for 3 hr at 25 degrees C reduced levels of 190H-PGEs2.5-fold and PGE22-fold, while increasing levels of PGAs and PGBs 2-fold. No 190H PGA or 190H PGB was detected in extracts of unincubated fluid. The PGAs, PGBs and their 19-hydroxy analogs are probably artifacts arising metabolically or as a result of classical isolation techniques.     

Oxanthrone C-glycosides and epoxynaphthoquinol from the roots of Rumex japonicus

Five oxanthrone C-glycosides, namely rumejaposide A-E, and an epoxynaphthoquinol, together with eight known compounds, 2,6-dihydroxy benzoic acid, 4-hydroxy benzoic acid, epicatechin, 4-hydroxy-3-methoxy benzoic acid, 2,6-dimethoxy-4-hydroxyl benzoic acid, rutin, emodin and 2-acetyl-1,8-dihydroxy-3-methyl-6-methoxynaphthalene, were isolated from the roots of Rumex japonicus. The structures of the oxanthrone C-glycosides were elucidated by application of spectroscopic methods as (10R)10-C-beta-glucopyranosyl-1,8,10-trihydroxy-2-carboxyl-3-methyl-9(10H)-anthracenone, (10S)10-C-beta-glucopyranosyl-1,8,10-trihydroxy-2-carboxyl-3-methyl-9(10H)-anthracenone, (10R)10-C-beta-glucopyranosyl-1,6,8,10-tetrahydroxy-2-carboxyl-3-methyl-9(10H)-anthracenone, (10R)10-C-beta-glucopyranosyl-1,6,8,10-tetrahydroxy-3-hydroxymethyl-9(10H)-anthracenone, and (10R)10-C-beta-glucopyranosyl-1,6,8,10-tetrahydroxy-3-methyl-9(10H)-anthracenone. Absolute configurations for each compound were deduced by analyses of CD spectra and comparison with those known similar compounds. The structure of epoxynaphthoquinol was elucidated by spectroscopic methods as 3-acetyl-2-methyl-1,4,5-trihydroxy-2,3-epoxynaphthoquinol, and its relative configuration was determined by a 2D-ROESY experiment.     

Effect of phosphomolybdic acid on the binding of Sudan black B

Paraffin sections of tissues fixed in absolute alcohol or Carnoy's fluid were mordanted in a 1% aqueous solution of phosphomolybdic acid, stained in saturated solutions of Sudan black B, acetylated Sudan black, various solvent and basic dyes in 70% ethyl alcohol for 5 min at room temperature, dehydrated in alcohol and covered in Permount. Sudan black B and other dyes with basic groups stained basement membranes, reticulum and collagen fibers intensely. Acetylated Sudan black, Sudan IV and oil red 0 did not color any tissue structures. Control sections, without pretreatment, did not bind Sudan black B. These findings indicate interaction between basic groups of the dye and free acid groups of phosphomolybdic acid.     

9-[(Hydroxymethyl)phenyl]adenines: new aryladenine substrates of adenosine deaminase

New phenyl adenine compounds 5-7 were synthesized as analogues of adenosine and studied for their adenosine deaminase (ADA) substrate activity. The 9-[(o-hydroxymethyl)phenyl]methyl]adenine 5 and 9-[(m-hydroxymethyl)phenyl]adenine 7 were deaminated by ADA, and 9-[(o-hydroxyethyl)phenyl]adenine 6 was not deaminated up to 7 days. The ADA substrates 5 and 7 were deaminated quantitatively to their inosine analogues in 10 and 6h, respectively.     

The Use of Bismarck Brown Y in some new Stain Schedules

The staining quality of Bismarck brown Y may be improved and sterility maintained by adding 5% phenol to a 1% aqueous solution. Use the phenolic Bismarck brown in combination with iron alum hematoxylin except for stripped epidermis in the following procedures:

Stem and Root Schedule: Mordant sections from water in 4% iron alum for 10 minutes. Rinse in distilled water and stain in 0.5% aqueous hematoxylin for 1 minute or until darkly stained. Rinse in distilled water and destain in 2% iron alum until a gray color appears. Rinse thoroly in distilled water and intensify hematoxylin by transferring sections to 0.5% aqueous lithium carbonate until the desired black color appears. Rinse thoroly in distilled water and stain for 1-5 minutes in phenolic Bismarck brown. Rinse in distilled water, dehydrate successively in 30, 50, 70, 95 and 100% alcohol. Clear in methyl salicylate for 5 minutes, then to xylene for 3-5 minutes, and mount in balsam.

Middle Lamellae in Wood: Destain more thoroly in 2% iron alum than for the general stem and root schedule, and intensify in lithium carbonate for a longer period (about 1 hour).

White Potato Tuber Sections: Modify above schedule by reducing time of destaining in 2% iron alum to about 30-60 seconds and intensify hematoxylin until starch grains appear bluish in color. Stain in phenolic Bismarck brown for 1-2 minutes.

Wheat Grain Sections: Fix grain for sectioning when in “dough” stage. Use schedule the same as for potato tuber except for reducing time of staining in phenolic Bismarck brown to about 45 seconds.

Tradescantia zebrina Epidermis: Strip epidermis from leaf while submerged in water. Fix in 100% alcohol 10 minutes, pass thru 95, 70, 50, 30, and 10% alcohol to water. Stain in phenolic Bismarck brown for 10-20 minutes. Dehydrate, clear in methyl salicylate and mount in balsam.     

Synthesis of the two monomethyl esters of the disaccharide 4-O-alpha-D-galacturonosyl-D-galacturonic acid and of precursors for the preparation of higher oligomers methyl uronated in definite sequences.

Methyl (alpha-D-galactopyranosyluronic acid)-(1-->4)-D-galactopyranuronate and methyl alpha-D-galactopyranosyl-uronate-(1-->4)-D-galactopyranuronic acid have been synthesized by coupling methyl (benzyl 2,3-di-O-benzyl-beta-D-galactopyranosid)uronate (3) or benzyl (benzyl 2,3-di-O-benzyl-beta-D-galactopyranosid)uronate (4) with benzyl (phenyl 2,3,4-tri-O-benzyl-1-thio-beta-D-galactopyranosid)uronate and methyl (phenyl 2,3,4-tri-O-benzyl-1-thio-beta-D-galactopyranosid)uronate, respectively, using N-iodosuccinimide and trifluoromethanesulphonic acid as promoters, followed by removal of the benzyl groups. The 4'-OH unprotected dimers benzyl (methyl 2,3-di-O-benzyl-alpha-D-galactopyranosyluronate)-(1-->4)-(benzyl 2,3-di-O-benzyl-beta-D-galactopyranosid)uronate and methyl (benzyl 2,3-di-O-benzyl-alpha-D-galactopyranosyluronate)-(1-->4)-(benzyl 2,3-di-O-benzyl-beta-D-galactopyranosid)uronate were prepared from methyl (phenyl 2,3-di-O-benzyl-1-thio-4-O-trimethylsilyl-beta-D-galactopyranosid) uronate and benzyl (phenyl 2,3-di-O-benzyl-1-thio-4-O-trimethylsilyl-beta-D-galactopyranosid) uronate and acceptors 4 or 3, respectively. These compounds have been designed to serve as precursors for the preparation of higher-membered D-galacturonic acid oligomers methyl esterified in definite positions.