Gibberellin-like Substances From Vegetative Tissue of a Conifer, Arizona Cypress

Vegetative shoots of Arizona cypress (Cupressus arizonica Greene) were found to contain an estimated 40 to 70 μg of gibberellin-like activity per kg. Based on elution patterns of silicic acid and celite partition columns, mobilities on thin layer chromatograms and specificity of the cucumber, d-3 dwarf maize, dwarf pea, and barley half seed bioassays it was possible to determine that the tissue contained at least 5 acidic, ethyl acetate-soluble gibberellin-like substances. The major one would appear to be GA₃. In addition, GA₉, GA₄, and/or GA₇-like compounds, and 2 unidentified gibberellin-like substances are present.     

Removal of the sphingolipid impurity from preparations of yeast phosphatidyl inositol

A complex sphingolipid containing inositol and mannose, present in lipid extracted from toluene-autolyzed baker's yeast, was eluted from silicic acid columns immediately after phosphatidyl inositol, and was the main nitrogenous impurity in crude preparations of this phospholipid. Nitrogenfree phosphatidyl inositol was obtained by rechromatography on alumina. Modifications to the chromatographic procedure also gave diphosphatidyl glycerol containing the theoretical 4.29% P.     

The lipids of mammalian pancreas

1. The total lipids of ox and guinea-pig pancreas were fractionated on silicic acid columns. 2. The high lipid content of both tissues was due to triglyceride. The major fatty acids of this triglyceride were stearic acid, palmitic acid and oleic acid. 3. The pattern of individual phospholipids resembled that of liver, though pancreas contained more plasmalogen.     

Selective adsorption of antirachitic sulfonated sterols

Adsorption columns of floridin, alumina, and silicic acid were used to study their capacities to concentrate the antirachitic activity in sulfonated cholesterol or two of its derivatives. Silicic acid was the most effective of these adsorbent materials. It proved more useful in adsorptions from ethylene chloride than from water suspensions.Silicic acid columns adsorbed acid fractions of sulfonated cholesterol in intermediate areas of color. These could be concentrated to a maximum of 50,000 A.O.A.C. units/g. by repeated elution, drying, and readsorption.Methylation of the active material prevented its adsorption.Similar results were obtained from sulfonated 3,4-diacetoxy-Δ⁵-cholestene but not from its isomer 3,6-diacetoxy-Δ^8,9-norcholestene.     

The amphipathic membrane proteins associated with gangliosides: The Paul-Bunnell antigen is one of the gangliophilic proteins

Two amphipathic protein fractions soluble in organic solvents as well as in water have been isolated from the ganglioside fraction of bovine erythrocyte membranes by successive chromatography in chloroform-methanol mixture on DEAE-Sephadex, silicic acid, and α-hydroxypropylated Sephadex G50 (LH60) columns. These two fractions contained a similar low molecular weight protein but with distinctively different amino acid composition. One of these proteins has been characterized by having a strong Paul-Bunnell antigen activity and had a binding affinity to ganglioside. A similar protein without Paul-Bunnell antigen activity was isolated as the major ganglioside-associated protein.     

Inhibitory effects of multicomponent, phosphonate-grafted, zwitterionic chitosan biomacromolecules on silicic acid condensation

This article reports the inhibitory effects of phosphonated chitosan (PCH, synthesized from chitosan (CHS) by a Mannich-type reaction) on the in vitro silicic acid condensation. In particular, the ability of PCH to retard silicic acid condensation in aqueous supersaturated solutions at circumneutral pH is studied. Furthermore, the effect of anionic carboxymethyl inulin (CMI) polyelectrolyte on the inhibitory activity of PCH is systematically studied. It was discovered that when PCH is added in dosages up to 150 ppm, it can inhibit silicic acid condensation, thereby maintaining soluble silicic acid up to 300 ppm (for 8 h, from a 500 ppm initial stock solution). The addition of CMI to working solutions that already contain PCH can further enhance the inhibitory action of PCH. A combination of 150 ppm PCH and 100 ppm CMI maintains 400 ppm soluble silicic acid for 8 h. PCH and CMI combinations also affect colloidal silica particle morphology.     

The effect of silicic acid on rice in a P-deficient soil

A pot experiment was conducted to analyze the effect of silicon on the growth of rice grown in a P-deficient soil and on P availability in the soil. Silicic acid was used, rather than a silicate salt, to avoid the complication of changes in soil pH.Shoot dry weight on silicic acid treated soil (0.47 mg Si g^–1 soil) increased significantly under both nonflooded and flooded conditions. Shoot Si concentration also increased although P concentration did not. Mn concentration decreased with silicic acid, resulting in a higher P/Mn ratio in shoots.An adsorption and desorption experiment showed that silicic acid did not displace P nor decrease the ability of the soil to adsorb P. In contrast, Si desorption increased with increasing P concentration in the solution, and Si adsorption was reduced when P was applied first.These results suggest that silicic acid does not increase P availability in soil. Increased dry weight may be attributed to a higher P/Mn ratio in the shoot, which may improve P utilization in the plant.     

The phospholipids of Pneumococcus I-192R, A.T.C.C. 12213: Some structural rearrangements occurring under mild conditions

1. The phospholipids from the non-capsulated strain of Pneumococcus I-192R, A.T.C.C. 12213, were separated into three fractions by chromatography on columns of silicic acid and DEAE-cellulose (acetate form). 2. The water-soluble phosphate esters produced by deacylation of each fraction were separated by chromatography on columns of DEAE-cellulose (HCO(3) (-) form). 3. Three deacylated products, diglycerol phosphate, glycerylphosphorylglycerol phosphate and bis(glycerylphosphoryl)glycerol, were identified by analysis, by chemical degradations and by comparison with synthetic materials. 4. From a study of freshly isolated lipids prepared and worked up under conditions where exposure to acid was minimal, it was concluded that the Pneumococcus contains phosphatidylglycerol and bisphosphatidylglycerol, in the molar proportion 1:2.5-3.0, and that the deacylation product glycerylphosphorylglycerol phosphate was probably an artifact of the isolation procedure. 5. Acid-catalysed isomerization (phosphodiester migration) of diglycerol phosphate and bis(glycerylphosphoryl)glycerol and transesterification (glycerol phosphate transfer) of diglycerol phosphate were observed. The structures of the products were established by degradation. 6. A novel mechanism for the biosynthesis of bisphosphatidylglycerol is presented.     

Chromatographic patterns of prostaglandins using different lots of silicic acid.

The chromatographic patterns of prostaglandin E2 chromatographed on various lots of silicic acid are presented. Two lots of Mallinckrodt silicic acid tested give totally unsatisfactory separation of PGE2. Sigma silicic acid SIL-R gives better separation than any of the Mallinckrodt lots tested. Increasing the size of the "E" fraction of solvent can give satisfactory separation on Mallinckrodt silicic acid.     

Group separation of bile acids and salts by silicic acid column chromatography

Group separations of unconjugated and conjugated bile acids and salts were performed using mixtures of conventional solvents by chromatography on columns of silicic acid. The results suggest that this method is useful for group separations of mono-, di-, and trihydroxycholan-24-oic acids and their conjugates with good recoveries. This method is advantageous for synthesis work, especially for the purification of conjugated and sulfated bile acids and salts, and is applicable for the group separation of glycine and taurine conjugates. The application of this method to human gallbladder bile salts is demonstrated.     

Absorption of aqueous inorganic and organic silicon compounds by wheat and their effect on growth and powdery mildew control

Soluble silicon, absorbed in the form of silicic acid by plant roots, confers efficient protection against many diseases. However, owing to its low solubility, there is a practical limit to increasing silicic acid availability to plants in the field. For this reason, methyl silanols – mono-, di- and trimethyl silicic acid – the water-soluble degradation products of silicone polymer, were evaluated for their ability to protect against powdery mildew in wheat grown under peat-based and hydroponic conditions. X-ray microanalysis indicated that only the monomethyl derivative was absorbed and deposited by wheat plants. Inductively coupled plasma–optical emission spectrometry measurements of total plant Si content confirmed this observation and indicated that monomethyl silicic acid remained mostly in its soluble monomeric form in planta. Mono- and trimethyl silicic acid offered no protection against powdery mildew and, indeed, yielded higher levels of infection than the control. Unexpectedly, dimethyl silicic acid induced severe symptoms of phytotoxicity early into the experiments at nutrient solution concentrations as low as 0.1 mM. For their part, both mono- and trimethyl silicic acid also caused symptoms of phytotoxicity by the end of the experiments. Our findings would suggest that silanols cannot be considered as substitutes for silicic acid in plants. Moreover, application of silicone-contaminated waste or sewage sludge to agricultural land needs to be evaluated with considerable care.     

Degradation of DNA by silicic acid

S1 nuclease hydrolysis and hydroxyapatite chromatography were used to study the effect of silicic acid on DNA. Native calf thymus DNA was incubated with increasing concentrations of silicic acid (DNA nucleotide/silicic acid molar ratios of 1:0.25, 1:0.5 and 1:1) and subjected to S1 nuclease hydrolysis. An increasing degree of DNA degradation was seen suggesting a destabilization of the secondary structure. A decrease in melting temperature was also observed. Hydroxyapatite chromatography indicated that incubation at the molar ratio of 1:1 resulted in denaturation and degradation of DNA.     

Electron micrographic study of precipitates formed by interaction of silicic acid and alkaline phosphatase: contribution to a study of silica urolithiasis in cattle

Association of alkaline phosphatase with silicic acid in precipitates formed in dilute solution was studied as a model for the nonspecific reaction between silicic acid and protein. Precipitates contained 68-83% of the silicic acid and 52-83% of the enzyme in the original mixture and were in the form of aggregates of roundish particles 150-800 nm in diameter. Enzyme protein formed a tightly bound layer on the surface of particles formed in solutions of freshly prepared silicic acid. The similarity between the ultrastructural features of precipitates from solutions of silicic acid and of internal portions of siliceous urinary calculi from cattle suggests that deposition of silica during development of such calculi is due, at least in part, to the interaction of protein with silicic acid in urine.     

Turnover of Phosphatidic Acid and Sodium Extrusion from Mammalian Erythrocytes

Phosphatidic acid (PA) from swine and beef RBCs was isolated by chromatography on silicic acid columns. It comprised about 1 per cent of the total lipid phosphate in RBCs, but was eluted nearly pure from columns. An uncharacterized inositide accounted for 5 to 10 per cent of the phosphate in the PA-containing fraction. When cells were incubated with HP³²O₄⁼, the fraction containing PA became more radioactive than any of the other fractions obtained. However, analysis of the labeled material by paper chromatography showed that most of the P³² was in the inositide, not in PA. With the assumption of kinetic homogeneity for cellular PA, compartmental analysis of the kinetics of tracer incorporation showed that PA turnover is 3 to 4 orders of magnitude too slow to account for sodium extrusion by these cells.     

Chromatographic patterns of prostaglandins using different lots of silicic acid

The chromatographic patterns of prostaglandin E₂ chromatographed on various lots of silicic acid are presented. Two lots of Mallinckrodt silicic acid tested give totally unsatisfactory separation of PGE₂. Sigma silicic acid SIL-R gives better separation than any of the Mallinckrodt lots tested. Increasing the size of the “E” fraction of solvent can give satisfactory separation on Mallinckrodt silicic acid.     

Human urinary sulfatides in patients with sulfatidosis (metachromatic leukodystrophy)

The excretion of sulfatides in human urine was studied. 24-hr urine collections were filtered. Urinary glycolipids were extracted from the filter paper and fractionated on diethylaminoethyl cellulose and silicic acid columns, and by thin-layer chromatography. Fatty acids and long-chain bases were analyzed by gas-liquid chromatography of the corresponding esters and aldehydes. Glycosyl ceramide concentration was determined by gas-liquid chromatography of the trimethylsilyl ethers of the methyl glycosides. Normal females were found to excrete larger amounts of dihexosyl ceramides than males. Sulfatides were detected in all urine specimens. In sulfatidosis, a hereditary sulfatide storage disorder known as metachromatic leukcdystrophy, a large increase in sulfatide was readily apparent on a thin-layer chromatogram of the crude lipid extract. On comparing samples from normal individuals and patients with sulfatidosis, urinary sulfatide composition was remarkably similar to that previously reported in the kidney, including differences in fatty acid pattern. The determination of urinary sulfatides was a valuable confirmation of the deficiency in arylsulfatase A activity characteristic of sulfatidosis.     

Strand breakage in DNA by silicic acid

The alkaline unwinding assay has been used to demonstrate the formation of single-strand breaks in DNA on treatment with silicic acid. Double-stranded DNA, containing no single-strand breaks, when incubated with increasing concentrations of silicic acid, showed the formation of an increasing number of strand breaks per molecule. Experiments on reduction of silicic acid-treated DNA with NaBH4 suggested the possibility of creation of apurinic or apyrimidinic sites. The significance of silicic acid interaction with cellular DNA during asbestos exposure is discussed.     

Identification and quantitation by radioimmunoassay of prostaglandin F compounds in bile

Separation and identification of prostaglandins in canine bile was performed by extraction and thin layer chromatography. The system provided tentative identification of the prostaglandin F compounds as the major prostaglandin subgroup present in bile. The prostaglandin was subsequently purified on silicic acid columns and quantitated by radioimmunoassay with tritiated PGF_2α and anti PGF_2α antibody employing the double antibody technique. Basal levels in hepatic bile were found to be 1028 ± 98 pg/ml.     

Vitamin A in the Vision of Insects

Acetone-methanol extracts of honeybees (Apis mellifera) were chromatographed from petroleum ether on columns of aluminum oxide and magnesium oxide:celite. Vitamin A₁ was identified by the Carr-Price (antimony chloride) reaction. These experiments provide the first demonstration of vitamin A in the tissues of an insect. Like retinene, vitamin A is confined to the heads and is not found in either thoraces or abdomens. Dark-adapted bees have very little vitamin A. During light adaptation the vitamin A increases, but at the expense of retinene, which decreases. As much as 0.1 µg of vitamin A/gm of heads has been recovered from light-adapted bees. Two methods are described for demonstrating the enzymic reduction of retinene to vitamin A, using an extract of the heads of honeybees.     

Release of slow reacting substance of anaphylaxis (SRS-A) from human leukocytes by the calcium ionophore A23187.

The ability of the calcium ionophore A23187 to release slow reacting substance of anaphylaxis (SRA-A) from human leukocytes was studied. About 25 times more SRS-A activity was released from aliquots of leukocytes by ionophore stimulation than by antigen stimulation, although comparable amounts of histamine were released. Cell separation studies revealed that granulocytes other than basophils were also capable of releasing SRS-A. The contractile activity released after challenge with ionophore appeared physicochemically identical to the SRS-A of rat or human origin released by antigen challenge in terms of its stability to base hydrolysis, inactivation by arylsulfatase, and chromatographic behavior on silicic acid and Sephadex LH-20 columns. We suggest that some mediators of allergic reactions previously associated, in man, only with antigen-IgE antibody interaction on mast cells or basophils may be released by other stimuli and from other cell types.