Dynamics of the accumulation of the alkaloids ofReseda luteola structure of lutine and lutinine

Summary The biosynthesis of the alkaloids ofAmmothamnus lehmannii Bge. have been studied by supplying the plants with [1,5-¹⁴C₂] cadaverine. It has been shown that cadaverine is a precursor of sophocarpidine, sophocarpine, and pachycarpine. Possible routes of interconversions have been studied by supplying the plants with the tritium-labelled alkaloids [³H] sophocarpine, [³H] matrine, and [³H] pachycarpine.V. I. Lenin Tashkent State University. Institute of Plant Biochemistry, Academy of Sciences of the German Democratic Republic, Halle. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 776–780, November–December, 1976.     

Acetylation of lagochilin

The acetylation of lagochilin and its derivatives with acetic anhydride in the presence of pyridine has been studied by PMR spectroscopy. It has been shown that the manifestation of the polyfunctionality of lagochilin in acetylation reactions with acetic anhydride is connected with a change in the nature of the process of solvation of the reaction forms with the subsequent replacement of the hydrogen atoms of the hydroxy groups by acetyl groups.V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 46–49, January–February, 1980.     

Synthesis of naphthyridines and phenanthrolines using catalysts based on transition and rare-earth metals

Liquid-phase condensation of 3-, 4-, and 8-aminoquinolines with aliphatic and aromatic aldehydes catalyzed by transition and rare-earth metal complexes is an efficient method for synthesis of substituted 1,7- and 1,6-naphthyridines and 1,10-phenanthrolines.Institute of Organic Chemistry, Ural Branch, Russian Academy of Sciences, 450054 Ufa; Eastern Scientific-Research Institute of Coal Chemistry, 620219 Sverdlovsk. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 5, pp. 1139–1148, May, 1992.     

Nature of mechanically induced defects in polycrystalline hydrargillite and Al2O3-A1(OH)3 studied by radiation methods

Mechanical treatment of hydrargillite Al(OH)₃ in a vibrational grinder and in a ball-mill grinder increases the dispersion, the specific surface area, and the unit-cell constants. An x-ray amorphous phase forms. Differences in the nature and in the concentration of paramagnetic centers arise on irradiation (77 K) of the mechanically treated samples. Anion vacancies and oxygen ions with disrupted short-range order appear in the mechanically treated samples. Their concentration increases with increased time of mechanical treatment. Pulsed thermal treatment of hydrargillite forms the Al₂O₃-Al(OH)₃ system and anneals the mechanically induced defects.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1463–1467, July, 1990.     

Beiträge zur Chemie der Silicium-Stickstoff-Verbindungen. CV. Ringschlußreaktionen mit 1,5-Bis(alkylamino)trisildioxanen

1.5-Bis(methylamino)hexamethyltrisildioxane reacts in the presence of triethylamine easily with germanium tetrachloride (equ. 1) and ethyldichlorophosphine (equ.2) to give the formerly unknown inorganic eightmembered ring systems Si₃GeN₂O₂ and Si₃PN₂O₂. Respectively. By analogous reacting of silicon tetrachloride only open chained Cl₃Si? Nme? Sime₂? O? Sime₂? O? Sime? NHme (IV; equ. 3) is formed. With metallated 1.5-bis(alkylamino)trisildioxanes, dischlorodiorganylsilanes do not give the expected asymmetric-, but the symmetric cyclotetrasildioxdiazanes V–VII. Dichlorophenylborane, in an analogous reaction, leads to the novel eightmembered ring system BSi₃N₂O₂, but the exact position of the N and O atoms in the ring could not be fixed beyond any doubt. The novel sixmembered ring system BSi₂Ni₂O was realized in compound IX via equ. (6).     

Time-resolved laser-induced fluorescence spectroscopy for enhanced demarcation of human atherosclerotic plaques

We report on the enhanced demarcation between human atherosclerotic plaques and normal vessel wall obtained using time-resolved detection of laser-induced fluorescence rather than the customary time-integrated monitoring technique. A frequency-doubled mode-locked and cavity-dumped continuous wave dye laser was used for picosecond pulse generation at 320 nm, and photon-counting techniques were employed for the time-resolved signal monitoring from human aorta samples in vitro. Implications for imaging fluorescence angioscopy and spectroscopic guidance in laser ablation of plaque are indicated.     

High-speed liquid and thin-layer chromatography of polychlorinated biphenyls.

High-speed liquid chromatography in the system silica gel/dry n-hexane and ultraviolet spectrometry have been used to study the composition of various types of commercially available mixtures of chlorinated biphenyls. Special attention has been paid to the analysis of highly chlorinated products. In addition to data previously published, retention times are recorded for 11 individual polychlorinated biphenyls. The results of high-speed liquid chromatography are compared with those obtained in several normal and reversed-phase thin-layer chromatographic systems.     

Measurements of inelastic cross sections for the (j,m) = (2,0)→(3,0) rotational transition of CsF in collisions with atoms and molecules

Individual state-to-state rotational transitions have been resolved in small angle scattering of polarized CsF molecules on Ne, Ar, C₂, H₆, N₂, CO, CO₂, CHF₃ at center of mass energies of about 0.1 eV. The absolute inelastic cross sections range from 5Ų up to 600Ų.     

Studies on amino acids and peptides-III. 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide,LR, as a new racemization free coupling reagent in peptide synthesis

The easily accessible 2,4-bis (4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide, $\text{LR}$, has been reacted with salts of N-protected amino acids $\text{1}$ (Z-Gly-OH, Boc-Gly-OH, Boc-S-Ser(Bzl)-OH, Boc-S-Tyr(Bzl)-OH, Z-S-Arg(Z₂)-OH, and Z-S-Pro-OH), at room temperature in CH₂Cl₂ to give the intermediates $\text{2}$, mixed anhydrides. When $\text{2}$ is treated with two moles of a base and one mole of the salt of an amino acid ester $\text{3}$ (TosOH·H-Gly-OBzl, HCl·H-Gly-OBzl, HCl·H-Gly-OEt, and HCl·H-S-Phe-OtBu) at 0°C, the expected peptide $\text{4}$ is isolated in high yields. LR is also found to be a useful reagent in a fragment coupling between Z-Gly-S-Ala-OH and TosOH·H-S-Leu-OBzl). This tripeptide was tested by means of HPLC (deprotection and amino acid analysis according to Izumiya was not necessary), and no epimerization (<0.7 %) was observed.     

Chemische Vitamin D<Subscript>3</Subscript>-Bestimmung in Lebertran

The different aspects of Vitamin D₃ determination and the data reported in the literature are discussed. The spectrophotometric determination of Vitamin D₃ in cod-liver oil is carried out after the alkaline saponification, extraction of unsaponified parts, precipitation of accompanying sterols and the column- and thin-layer chromatographic purification and separation of vitamin D₃ on 40 cm plates from other vitamins. The dyestuff α-naphtholbenzein is suited well as standard substance for the better location and identification of vitamin D₃ zone on the thin-layer plate. The results obtained from the chemical method were checked through the simultaneous biological determination.