Colorless Powder Research Articles

Mulundocandin, a new lipopeptide antibiotic. I. Taxonomy, fermentation, isolation and characterization.

Mulundocandin, a new lipopeptide antibiotic, was isolated from the culture broth of a strain of Aspergillus sydowi No. Y-30462. The antibiotic, obtained as a colorless amorphous powder having the molecular formula C48H77N7O16, is an antifungal antibiotic active against yeasts and filamentous fungi.

Radical high polymerization of dialkyl fumarates with bulky substituents leading to less-flexible rod-like polymers

Dialkyl fumarates with bulky ester substituents were found to homopolymerize easily in the presence of 2,2′-azobisisobutyronitrile. Among these fumarates, diisopropyl fumarate (DiPF) homopolymerized with the above initiator (20mmol/1) in bulk at 40∼60°C to give homopolymers with number-average molecular weight of 70 000∼221 000. Similar results were also observed for di-t-butyl fumarate (DtBF) and Methyl-t-butyl fumarate (MtBF). These polymers were found to consist of a lessflexible rod-like (polyalkoxycarbonylmethylene) from the molecular model and the solution property measurements. These polymers which were colorless powders did not melt before thermal degradation, but they were soluble in most organic solvents. From TG thermogram observed in a nitrogen atmosphere, the DiPF polymer showed T(init.)=257°C and T(max.)=316°C, and the main degradation products at 400°C, except gaseous materials, were isopropanol and DiPF monomer (32:1 in mole ratio). These thermal degradation behavior was different from that for the polymers of DtBF and MtBF which underwent degradation from lower temperatures like 190°C. Acid and alkaline hydrolyses of the DiPF polymer were observed to occur very hardly.

A New Growth Inhibitor, Pisumin, Involved in Light Inhibition of Epicotyl Growth of Dwarf Peas

A new growth inhibitor, tentatively named pisumin, which increased under red light and remained at initial level or decreased when dwarf pea (Pisum sativum L. cv Progress No. 9) seedlings were transferred from red light to dark, has been isolated in the form of a colorless powder from light-exposed epicotyls of dwarf peas, and characterized partially as an aliphatic carboxylic acid (molecular weight 284) by spectrometric analyses.Exogenous pisumin inhibited the growth of epicotyl segments of dwarf peas at concentrations higher than 0.1 millimolar in the dark.

Vanoxonin, a new inhibitor of thymidylate synthetase.

Vanoxonin, a new inhibitor of thymidylate synthetase, was found in cultured broths of the strain MG245-CF2 classified as Saccharopolyspora hirsuta. Vanoxonin, C18H25N3O9, was obtained as colorless powder. Vanoxonin forms a vanadium complex which exhibits a strong inhibition against thymidylate synthetase. The concentration for 50% inhibition of the enzyme (IC50) was 0.7 micrograms/ml.

Zur Rutilverwandtschaft: Zur Kenntnis von LiSrFeF6[1]/On the Knowledge of LiSrFeF6

Hitherto unknown LiSrFeF6 was obtained by heating mixtures of binary fluorides [LiF + SrF2 + FeF3; Li:Sr:Fe = 1:1:1] under argon [Au tubes, 500 °C, 2 d or 650 °C, 14d] as a colourless powder or colourless single crystals. LiSrFeF6 crystallizes monoclinicly in P21/c-C5 2h with a = 5,2972(4), b = 8,7989(8), c = 10,2257(7) Å, β = 92,212(8)°, Z = 4; drö = 3,69 und dpyk = 3,66 g · cm-3, positions are given in the text, R = 9,16% (Rw = 6,83%) for hkl (Mo-Ka, 4-circle diffractometer data).

The properties of aluminium stearate and its uses in the coatings and allied industries

Aluminium stearate is a fine, bulky, odourless and colourless powder forming a plastic mass when heated, having the properties both of organic and inorganic matter. It embraces most of the characteristics of other metallic stearates and is regarded as the most important of these. Several studies of the material have already appeared in past years.

Zur kenntnis von [O2]22+[Ti7F30]2−

[O2]2+2[Ti7F30]2− has been obtained by reaction of TiO2 with a mixture of fluorine and oxygen (pF2/O2 ≈ 300–3500 atm., t ≈ 300–450°C) either as colourless powder or in form of colourless, clear needles. From single crystal studies the spacegroup is P3 - C3i1 (No. 147) with a = 10.192, c = 6.50o Å, Z = 1. The crystal structure has been refined to R = 0.086 [Rw = 0.058] (748 unique reflexions [Fo > 2σ(Fo)]). From the structure determination [O2]2+2[Ti7F30]2− has isolated columns of partially distorted [TiF6] octahedra (- column structure) which are connected only quite loosely by (disordered) O2+ cations. νO2+ is at 1857 cm−1, the magnetic moment μeff = 2.35 B.M. (295 K) is quite as expected for a ‘spin-only’ case.

Isolation of octapeptin D (studies on antibiotics from the genus Bacillus. XXVII).

A new peptide antibiotic complex, named octapeptin D, was isolated from culture broth of a microorganism belonging to the genus Bacillus. The trihydrochloride of the antibiotic was obtained as a colorless powder, soluble in water and methanol. The empirical formula, C47H88N12O11.3HCl.H2O, was indicated by elemental analysis. Amino acid analysis on the acid hydrolyzate demonstrated the presence of 2,4-diaminobutyric acid (4 moles), serine (1 mole) and leucine (3 moles). Gas chromatographic analysis with the methylated product of the ethereal extract of the acid hydrolyzate revealed the presence of beta-hydroxy isodecanoic acid, beta-hydroxy decanoic acid, beta-hydroxy isoundecanoic acid and beta-hydroxyanteisoundecanoic acid. Octapeptin D is active against Gram-negative and Gram-positive bacteria in vitro and in vivo.

Solvent effects of fluorides in cubic BN high pressure synthesis

Cubic BN can be synthesized under high pressure by using various fluorides as solvents. When NH 4F solvent is used, synthesis conditions are pressures above 4.0 GPa and temperatures above 800°C at 6.0 GPa. However, there exists a lower pressure limit for the synthesis, as in the case of water solvent. Synthesized cubic BN is a colorless tetrahedral crystalline powder with crystal size varying from 0.2 – 1 μm. Spark ion source mass spectrography revealed that the resulting cubic BN and hexagonal BN contain fluorine. This indicates that fluorine plays a role in the shift of the cubic-hexagonal BN equilibrium line to the higher pressure side, creating a pressure limit for the synthesis.

Isolation and Chemical Structure of a New Fluorescent Compound in Spinach Leaves

The present paper describes, together with its isolation procedures, the chemical structure determined for an unknown blue-violet fluorescent compound present in spinach. The effective isolation procedures consisted of methanol extraction from 30 kg of spinach leaves, column chromatographies on cellulose powder and DEAE-cellulose, and gel filtration through Sephadex columns. The compound was obtained as colorless powder in the yield of 70 mg. It was identified as 2-acetyl-3-(p-coumaroyl)-meso-tartaric acid basing on the spectral data and the experimental results of alkaline hydrolysis and chemical synthesis.

Synthesis of N-Terminal Nonapeptide of Trypsinogen and Its Hydrolysis by Trypsin

Abstract An N-terminal nonapeptide fragment of bovine trypsinogen, H-l-Val-l-Asp-l-Asp-l-Asp-l-Asp-l-Lys-l-Ile-l-Val-Gly-OH, was synthesized via two routes and its susceptibility with trypsin was investigated. Protected derivatives, t-butyloxycarbonyl protected nonapeptide t-butyl ester and benzyloxycarbonyl protected nonapeptide benzyl ester, were prepared by stepwise elongation. Removal of the protecting groups was carried out by treatment with trifluoroacetic acid and hydro-genation respectively. The naked peptide was purified with chromatography on ECTEOLA cellulose column using dilute acetic acid as a solvent. Upon lyophilization the desired nonapeptide was obtained as colorless powder, a portion of the product being digested with trypsin. Rate of tryptic hydrolysis of the peptide was found to be unexpectedly low in the absence of calcium ion, while considerable acceleration of the hydrolysis by calcium ion was noted.

Enduracidin, a new antibiotic. II. Isolation and characterization.

Enduracidin is a basic compound with ultraviolet absorption maxima at 230 and 263mμ in 90% methanol and is a colorless crystalline powder de composing at 225-240°C. It is positive to DRAGENDORFF, ninhydrin, BIURET and BARTON'S1) reagents but negative to Molisch reagent. Hydrolysis of en duracidin with 6n HC1 yields, aspartic acid, threonine (and/or allo-threonine), serine, glycine, alanine, ornithine, citrulline, α-amino-4-hydroxyphenylacetic acid, α-amino-3, 5-dichloro-4-hydroxyphenylacetic acid and two unidentified basic amino acids.

Sugar polythioacetals

AbstractSugar polythioacetals have been prepared by polymerization of sugars with dithiols in dioxane solution with hydrogen fluoride catalyst. Polymerization was also carried out by using liquid hydrogen fluoride as solvent and catalyst. The polymers are colorless powders with inherent viscosities in the range of 0.03–0.24 and melting points of 81–160°C. The polythioacetals of the shorter‐chain dithiols are soluble in polar solvents; those of the longer‐chain dithiols are partially soluble.

The synthesis and properties of crystalline polymers of the type of poly‐p‐xylenes and polyphenylene methyl derivatives

AbstractFor the purpose of obtaining polymeric hydrocarbons of enhanced thermostability, linear polymers of regular structure of the type (CH2ArCH2)n and (ArCH2)a with aromatic units in the chain were synthesized. Polymers of the first type were obtained by reaction of metallic sodium with the dichloromethyl derivatives of benzene, m,‐ and p‐xylenes, diphenylmethane, diphenyl and naphthalene in dioxane medium at 20–25°C. The m‐xylene derivative had a CH2Cl group in the m‐position and the others, dichlorides in the p‐ or p,p′‐positions. The polymers were precipitated from the solutions on forming and after removal of excess sodium with the aid of methanol and elimination of the low molecular impurities they appeared as colorless powders of the composition of hydrocarbons, at times containing chlorine. X‐ray analysis of the polymers revealed the presence of a crystalline structure the degree of which varied, depending upon the structure. The polymers differed greatly in solubility and melting points. Thus naphthalene and diphenyl derivatives, evidently being crosslinked three‐dimensional polymers, did not dissolve even in boilling α‐bromonaphthalene and decomposed above 300° and 550° without melting, while derivatives of other hydrocarbons dissolved in bromonaphthlene, melted, and probably were linear polymers of low molecular weight. The m‐xylene derivative was distinguished by low crystallinity, low melting point (130–135°C.) and easily dissolved in chloroform even in the cold. Diphenylmethane derivatives with a more clearly expressed crystallinity melted at 250–255°C. and began to dissolve in α‐bromonaphthaline only at 130°C. p‐Xylene derivatives, like poly‐p‐xylylene, were highly crystalline and melted at 350°, but began to dissolve in bromonaphthalene only at 235°. The molecular weight of the soluble polymers could be determined (according to Rast's method) only for the soluble m‐xylene derivative, which, depending upon the conditions of formation, varied from 1850 to 4000. Polymers of the second type were obtained by polycondensation of aromatic hydrocarbons with paraform and also with the dichloro‐, dioxy‐, and diacetoxymethyl derivatives of aromatic hydrocarbons in boiling glacial acetic acid containing sulfuric acid. In this way starting from p‐xylene and durene one could obtain high‐melting crystalline polymers with melting points above 250 and 320°, dissolving only in high boiling solvents. Condensation of durene with dichloromethyl derivatives of p‐ and m‐xylene as well as with p‐xylylene chloride led to the formation of high melting polymers of the type (ArCH2Ar′CH2)n containing two different aromatic units in the chain.

Studies on the Constituents of Digitalis purpurea L. XVII. Isolation of Several New Glycosides from Fraction PGB of Digitalis Seeds.

Several new glycosides were isolated from digitalis seeds, four substances, B-I, A-III', C-0, and X2, were obtained as crystals, and five substances, PGA, A-II', B-I', PGB, and A-III, were obtained as a colorless powder. In accordance with their coloration, it was assumed that substances B-0, PGA, B-I', and C-0 belong to the digitoxigenin series, and substances A-II', A-II, PGB, A-III, and A-III'to the gitoxigenin series.

Studies on the Constitutents of Digitalis purpurea L. X. Isolation of Several New Glycosides from the Water-soluble Fraction of Digitalis Seeds.

Several new glycosides were isolated from digitalis seeds. Five substances, A-VI acetate, C-I', A-VII, B-II, and X1, were obtained as crystals, and four substances, B-III, C-II, A-VII', and B-III', were obtained as a colorless powder. In accordance with their colorations and absorption spectra, it was assumed that A-VI, A-VII', B-III, and B-III' belong to gitoxigenin series, C-I' and C-II to digitoxigenin series, and B-II to digitanol series.

RELATIVE TOXICITY OF COCAIN AND EUCAIN.

Cocain hydrochlorate is a white crystalline alkaloid obtained from the leaves of the erthroxylon coca, a small shrub of Peru and other western South American countries. Its extensive use as a local anesthetic is so familiar to all that repetition is here unnecessary. It is not my intention in this paper to especially refer to its anesthetic properties, only its toxic effects relatively with those of eucain, as observed in actual practice and as determined by original experimentation. Eucain is a colorless crystalline powder of German production, and was placed on the market some years ago as an anesthetic to be used in a similar manner to cocain. It was soon observed that the first product, or that which is now called Alpha Eucain, produced many undesirable and some very disagreeable effects, so much so that its use was soon largely discontinued. In February, 1897, Dr. Silex of Berlin brought