SEPARATION OF ENDOMYCINS A AND B, AND THEIR IDENTIFICATION AS MEMBERS OF THE POLYENE GROUPS OF ANTIFUNGAL ANTIBIOTICS

1957 ◽  
Vol 35 (12) ◽  
pp. 1461-1466 ◽  
Author(s):  
L. C. Vining ◽  
W. A. Taber
Keyword(s):  
Absorption Spectra ◽  
Paper Chromatography ◽  
Ultraviolet Absorption ◽  
Countercurrent Distribution ◽  
Double Bonds ◽  
Active Components ◽  
Streptomyces Species ◽  
Antifungal Antibiotics

An unidentified Streptomyces species isolated from platings of "honey dew" of the fungus Clavicepspurpurea produced two antifungal antibiotics which were shown by paper chromatography to be identical with the two active components of endomycin, and also with helixins A and B. An examination of the ultraviolet absorption spectra of the three complexes showed maxima at wavelengths associated with two unsaturated systems containing four and six conjugated double bonds respectively. The two unsaturated components were separated by countercurrent distribution and shown to correspond to the two active fractions. The tetraene has been named endomycin A, and the hexaene endomycin B. Flavacid, a polyene complex also containing tetraene and hexaene components, is not identical with endomycin.

URINARY EXCRETION PRODUCTS OF MENADIONE (VITAMIN K3)

1954 ◽  
Vol 32 (3) ◽  
pp. 240-250 ◽  
Author(s):  
F. C. G. Hoskin ◽  
J. W. T. Spinks ◽  
L. B. Jaques
Keyword(s):  
Body Weight ◽  
Guinea Pig ◽  
Urinary Excretion ◽  
Absorption Spectra ◽  
Vitamin K ◽  
Paper Chromatography ◽  
Ultraviolet Absorption ◽  
Chemical Analyses ◽  
Vitamin K3 ◽  
Dosage Range

Radioactive vitamin K3 (2-methyl-C14-1,4-naphthoquinone) was administered to rats and the radioactive urinary products separated by paper chromatography and identified by ultraviolet absorption spectra and chemical analyses. Over the dosage range of 2.6 to 11.0 mgm. per kgm. of body weight, 2-methyl-C14-1,4-naphthoquinone was excreted, in order of decreasing relative concentrations as the diglucuronide (Product 1), the monosulphate (Product 2), and a third partially identified derivative of the vitamin (Product 3). Following the administration of vitamin K3, these products were excreted by normal rats, a dicoumarol-poisoned rat, and a guinea pig. The relative concentrations in the urine of Products 1 and 2 varied directly with the size of dose of vitamin K3. At these dosages, little or no vitamin K3 is excreted in urine as such.

URINARY EXCRETION PRODUCTS OF MENADIONE (VITAMIN K3)

1954 ◽  
Vol 32 (1) ◽  
pp. 240-250 ◽  
Author(s):  
F. C. G. Hoskin ◽  
J. W. T. Spinks ◽  
L. B. Jaques
Keyword(s):  
Body Weight ◽  
Guinea Pig ◽  
Urinary Excretion ◽  
Absorption Spectra ◽  
Vitamin K ◽  
Paper Chromatography ◽  
Ultraviolet Absorption ◽  
Chemical Analyses ◽  
Vitamin K3 ◽  
Dosage Range

Radioactive vitamin K3 (2-methyl-C14-1,4-naphthoquinone) was administered to rats and the radioactive urinary products separated by paper chromatography and identified by ultraviolet absorption spectra and chemical analyses. Over the dosage range of 2.6 to 11.0 mgm. per kgm. of body weight, 2-methyl-C14-1,4-naphthoquinone was excreted, in order of decreasing relative concentrations as the diglucuronide (Product 1), the monosulphate (Product 2), and a third partially identified derivative of the vitamin (Product 3). Following the administration of vitamin K3, these products were excreted by normal rats, a dicoumarol-poisoned rat, and a guinea pig. The relative concentrations in the urine of Products 1 and 2 varied directly with the size of dose of vitamin K3. At these dosages, little or no vitamin K3 is excreted in urine as such.

ÉTUDE DE L'ACTIVITÉ BIOLOGIQUE IN VITRO DES HORMONES GONADOTROPES

1960 ◽  
Vol XXXIII (III) ◽  
pp. 444-450 ◽  
Author(s):  
Maria de la Luz Suarez Soto ◽  
Jean Legault Démare
Keyword(s):  
Paper Chromatography ◽  
Incubation Medium ◽  
Ultraviolet Absorption ◽  
Rat Ovary

ABSTRACT Serum gonadotrophin (PMS) when added to the incubation medium of rat ovary slices increases the amount of Δ4-3-ketosteroids produced. This enhancement is proportional to the logarithm of dose. The ketosteroids were determined by their ultraviolet absorption; paper chromatography has shown that only androst-4-en-3,17-dione is present.

FAR ULTRAVIOLET ABSORPTION SPECTRA OF N3AND N2+GENERATED BY ELECTRONS IMPACTING GASEOUS N2

2013 ◽  
Vol 779 (1) ◽  
pp. 40 ◽  
Author(s):  
Yu-Jong Wu ◽  
Hui-Fen Chen ◽  
Shiang-Jiun Chuang ◽  
Tzu-Ping Huang
Keyword(s):  
Absorption Spectra ◽  
Ultraviolet Absorption ◽  
Far Ultraviolet

scholarly journals ULTRAVIOLET ABSORPTION SPECTRA AT REDUCED TEMPERATURES

1950 ◽  
Vol 187 (1) ◽  
pp. 299-312
Author(s):  
R.L. Sinsheimer ◽  
J.F. Scott ◽  
J.R. Loofbourow
Keyword(s):  
Absorption Spectra ◽  
Ultraviolet Absorption

scholarly journals Spectral Probe for Electron Transfer and Addition Reactions of Azide Radicals with Substituted Quinoxalin-2-Ones in Aqueous Solutions

2021 ◽  
Vol 22 (2) ◽  
pp. 633
Author(s):  
Konrad Skotnicki ◽  
Slawomir Ostrowski ◽  
Jan Cz. Dobrowolski ◽  
Julio R. De la Fuente ◽  
Alvaro Cañete ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Aqueous Solutions ◽  
Absorption Spectra ◽  
Density Functional ◽  
Reduction Potential ◽  
Biological Significance ◽  
Radical Cations ◽  
Basis Sets ◽  
Double Bonds ◽  
Reduction Potentials

The azide radical (N3●) is one of the most important one-electron oxidants used extensively in radiation chemistry studies involving molecules of biological significance. Generally, it was assumed that N3● reacts in aqueous solutions only by electron transfer. However, there were several reports indicating the possibility of N3● addition in aqueous solutions to organic compounds containing double bonds. The main purpose of this study was to find an experimental approach that allows a clear assignment of the nature of obtained products either to its one-electron oxidation or its addition products. Radiolysis of water provides a convenient source of one-electron oxidizing radicals characterized by a very broad range of reduction potentials. Two inorganic radicals (SO4●−, CO3●−) and Tl2+ ions with the reduction potentials higher, and one radical (SCN)2●− with the reduction potential slightly lower than the reduction potential of N3● were selected as dominant electron-acceptors. Transient absorption spectra formed in their reactions with a series of quinoxalin-2-one derivatives were confronted with absorption spectra formed from reactions of N3● with the same series of compounds. Cases, in which the absorption spectra formed in reactions involving N3● differ from the absorption spectra formed in the reactions involving other one-electron oxidants, strongly indicate that N3● is involved in the other reaction channel such as addition to double bonds. Moreover, it was shown that high-rate constants of reactions of N3● with quinoxalin-2-ones do not ultimately prove that they are electron transfer reactions. The optimized structures of the radical cations (7-R-3-MeQ)●+, radicals (7-R-3-MeQ)● and N3● adducts at the C2 carbon atom in pyrazine moiety and their absorption spectra are reasonably well reproduced by density functional theory quantum mechanics calculations employing the ωB97XD functional combined with the Dunning’s aug-cc-pVTZ correlation-consistent polarized basis sets augmented with diffuse functions.

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