Isolation and distribution of adenochrome(s) in Octopus vulgaris lam.
Explore the source record for details and available documents.
Amino Acids↗
SEARCH · PubMed Health
Results for “Spectrophotometry, Infrared”
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Glycosides of marine invertebrates. IV. A comparative study of the glycosides from Cuban sublittoral holothurians.
Explore the source record for details and available documents.
Animals↗
Poly-beta-hydroxybutyric acid in staphylococci.
Poly-beta-hydroxybutyric acid (PHB) was extracted from various species of staphylococci isolated from different sources. IR and UV spectrophotometry and NMR analysis revealed that the compound consisted only of the beta-hydroxybutyrate. The PHB level in the richest strain among investigated staphylococci is about 64-fold less than in bacilli. The intrinsic viscosity number of this polymer is more than twice greater in the case of the staphylococcal product than that of bacilli.
Hydroxybutyrates↗
Neonatal water metabolism: an objective postnatal index of intrauterine fetal growth.
The water metabolism of 103 newborn babies was determined over the first 10 postnatal days, by measuring water turnover rates by means of an isotope dilution technique. This technique involves the oral administration of the non-radioactive isotope of water, 2H2O, and the measurement of its urinary excretion by infrared spectrophotometry. The slope of the excretion curve after equilibration with the infant's body water was mathematically expressed as the rate constant. Using multiple obstetric and paediatric criteria, the babies were clinically classified into one of three categories, fully grown ("normal'), borderline or clearly growth retarded. The median values of the rate constants X 10(4) (h-1) for the three groups were 73.3, 85.9 and 100.2 and were highly significantly different from each other (P less than 0.0005) with no overlap of the 97% non-parametric confidence limits of each group. Neonatal water turnover increased with the clinical degree of intrauterine fetal growth retardation and within the limits of this study, this finding was unaffected by gestational age, birth weight or the neonatal environment. The results suggest that neonatal water metabolism is an objective postnatal index of fetal growth retardation.
Body Water↗
The occurrence of phthalic acid esters in various samples of commercially available sodium chloride injections (Indian Pharmacopoeia).
Conclusive evidence for the presence of di(2-ethylhexyl) phthalate (DEHP) in 15 out of 17 commercially available sodium chloride injection (Indian Pharmacopoeia) samples was obtained and concentration levels as high as 11.0 mg/500 ml of saline were detected. The presence of such contaminants in i.v. fluids, avoidable by the institution of appropriate quality control measures before manufacturing and marketing, is a matter of serious concern. Stipulated specifications in different pharmacopoeias are meant only to ensure sterility and pyrogenicity, and it is advisable that cognisance be taken of the presence of toxic contaminants e.g. di(2-ethylhexyl) phthalate.
Diethylhexyl Phthalate↗
Alkaloids from Macoubea guianensis seeds.
From the seeds of Macoubea guianensis (Apocynaceae), mixtures of the antipodes of two indole alkaloids, vincadifformine and vincadine, have been isolated; in the first the (+)- and in the second the (-)-isomer predominated.
Alkaloids↗
Structure and chemotherapeutical activity of a polyisoprenylated benzophenone from the stem bark of Garcinia huillensis.
The stem bark of Garcinia huillensis grown in Zaïre and used in central-African traditional medicine has been subjected to a bioassay-guided fractionation. The chemotherapeutically active petroleum ether extract afforded fatty acids, aliphatic alcohols, triterpenes and a polyisoprenylated benzophenone, which was identified as garcinol, also named camboginol. This compound has been shown to exhibit chemotherapeutical activity gram-positive and gram-negative cocci, mycobacteria and fungi. On the other hand garcinol has been found to be inactive against gram-negative enteric bacilli, yeasts and viruses.
Antiviral Agents↗
Isolation and identification of the antibacterial compounds from Helichrysum stoechas.
Fractionation of the dicholoromethane extract of the aerial parts of Helichrysum stoechas yielded seven isolates (1-7), which exhibited varying antimicrobial activity against Gram-positive bacteria. Pure compounds 1-3 have been previously reported in the same species and 4 and 5 were identified as italipyrone and plicatipyrone, previously isolated from H. italicum and H. plicatum. The two other isolates are helipyrone (6) and homoarenol (7) mixed with related substances. Compound 6c (4,4'-dihydroxy-5,6,5',6'-tetramethyl-3,3'-methylen-di-pyr-2-one) and 6b helipyrone with one methyl substitution, have not been previously reported in other species.
Anti-Bacterial Agents↗
Validation of a method for the assay of related compounds in famotidine raw materials and formulations.
A high-performance liquid chromatographic (HPLC) method has been developed for the determination of famotidine and related compounds in drug raw materials and formulations. The minimum detectable amount of the available related compounds is less than 0.02% and the minimum quantifiable amount is less than 0.1%. Famotidine impurity levels were between 0.5 and 2.5% in raw materials. 0.44% in one tablet sample and about 3% in an IV solution, allowing for stabilizers.
Chromatography, High Pressure Liquid↗
Chromatographic and spectroscopic studies on the constituents in male and female flowers of Hagenia abyssinica.
The phenolic constituents of male and female flowers of Hagenia abyssinica were examined using chromatographic and spectroscopic techniques. Chromatographic analysis of kosins (phloroglucinols) was carried out using TLC, reversed-phase LC and glass-capillary GLC. Purification of the crude kosins was effected by silica gel column chromatography and purification of phenolic acids using ion-exchange resins and preparative TLC on silica gel. The kosins were characterized by TLC, LC, UV, IR, MS and H1 NMR spectroscopy while the phenolic acids were characterized by UV-spectroscopy, TLC and LC. The phenolic acids found were protocatechuic acid, p-hydroxybenzoic acid and vanillic acid. The content of the kosins and phenolic acids was established quantitatively for both male and female flowers.
Africa, Eastern↗
Synthesis and spectroscopic studies of norethylmorphine.
Explore the source record for details and available documents.
Chromatography, High Pressure Liquid↗
Estimation of impurity profiles in drugs and related materials. Part 11--The role of chromatographic and spectroscopic methods in the estimation of side-reactions in drug syntheses.
Impurities in drugs are classified on the basis of the types of side-reactions in drug syntheses resulting in their formation. This is shown by summarizing the authors' earlier results in the field of impurity profiling of 19-nor-steroids, ethynodiol diacetate, mazipredone, pipecuronium bromide, flumecinol, enalapril, pyridinol carbamate, phenylbutazone, thymotrinan and some new results related to danazol and famotidine.
Chemistry, Pharmaceutical↗
Coulometric determination of nizatidine.
Explore the source record for details and available documents.
Bromine↗
Structure elucidation of 6-chloro-2-methyl-4(1H)-quinazolinone, a photodecomposition product of midazolam.
Explore the source record for details and available documents.
Chromatography, Thin Layer↗
Analytical applications of retinoid-cyclodextrin inclusion complexes. 1. Characterization of a retinal-beta-cyclodextrin complex.
In studies in these laboratories on the supramolecular chemistry of the retinoids, it has been recently confirmed that inclusion of these substances within the cavity of cyclodextrins protects their excited states, thus improving their photochemical stability. In the present paper, the isolation is described of a crystalline stable complex between retinal and beta-cyclodextrin, which has been characterized by means of several techniques including atomic force microscopy (AFM). The complex shows distinct spectroscopic differences from both retinal and beta-cyclodextrin. Thus, it absorbs at lambda(max) = 380 nm in water whereas retinal is insoluble; it shows room-temperature luminescence, which retinal does not; finally, it give 1H-NMR and 13C-NMR spectra in d6-DMSO with clear differences in chemical shifts with respect to those of beta-cyclodextrin. Besides these studies in solution, the behaviour of the complex in the solid state has been compared with that of physical mixtures of retinal and beta-cyclodextrin. IR spectroscopy shows clear differences, particularly a shift in the retinal carbonyl absorption (1644-1672 cm-1). AFM studies reveal the existence of aggregates; X-ray diffractometry also supports the formation of a cyclodextrin-retinal complex.
Cyclodextrins↗
A comparison of toxins isolated from the cyanobacteria Oscillatoria agardhii and Microcystis aeruginosa.
1. A toxin isolated from a strain of Oscillatoria agardhii var. was compared to a peptide toxin isolated from Microcystis aeruginosa. 2. The Oscillatoria toxin possessed similar hepatotoxic properties on mice as the Microcystis toxin but had a higher LD50 than the latter; 320 micrograms/kg compared to 43 micrograms/kg (i.p. mouse), respectively. 3. Ultra-violet and infra-red spectra showed that the Oscillatoria toxin is a peptide which is not identical to the Microcystis toxin. 4. The spectra also indicated some structural similarities in these toxins.
Animals↗
Synthesis, characterization and biodistribution of tris(beta-diketonato)technetium(III) complexes.
New tris(beta-diketonato) complexes of trivalent 99Tc/99mTc with the ligands hexane-2,4-dione, heptane-2,4-dione, heptane-3,5-dione, and octane-3,5-dione were synthesized by reduction of pertechnetate with dithionite in the presence of excess beta-diketone. The complexes were purified by HPLC, identified by elemental analysis and FAB mass spectrometry, and characterized by vis./u.v./i.r. spectrophotometry. The hexane-2,4-dionato complex crystallizes in the monoclinic space group P21/c, isostructurally with pentane-2,4-dionatotechnetium(III). Biodistribution measurements in mice showed the neutral and lipophilic 99mTc-diketonato complexes to penetrate the blood-brain barrier. However, increasing lipophilicity decreased the brain uptake except for the heptane-2,4-dionato complex, which displayed the highest uptake of 0.82% injected dose/g.
Animals↗
Technetium-99m radiolabeled ouabagenin-cysteine conjugate: biological evaluation in animal models.
Two ouabagenin-cysteine conjugates were synthesized by condensing 3-beta monochloroacetyl and 3-beta, 11-alpha dichloroacetyl ouabagenin with cysteine. The resulting ligands were radiolabeled with technetium-99m (99mTc) to furnish a single homogenous 99mTc chelate in each case with good stability. The animal experiments with these 99mTc-labeled conjugates established the superiority of guinea pig over rat and rabbit as an animal model, as previously observed for other tritiated or radioidinated cardiac glycosides or aglycones. In biodistribution experiments in guinea pig, these 99mTc chelates showed a favorable heart to liver (and other nontarget organ) uptake ratio, comparable to that of recently reported 125I-digoxigenin iodohistamine-3-oxime. The low heart to blood ratio in animal experiments with ouabagenin derivatives could be attributed to the absence of 3-beta sugar residues in these molecules, which is in agreement with the previous observation reported in connection with radioiodinated digoxin and digoxigenin derivatives.
Animals↗