O-acylated flavonoid glycoside of the needles ofPicea obovata

Summary From the needles of the Siberian spruce we have isolated a new diacylated flavonoid glycoside (I) for which we have established the structure of 3-(3-O-p-coumaroyl-6-O-feruloyl-glucopyranosyloxy)-4,5,7-trihydroxyflavone.The new acylated glucoside 6-O-feruloylastragalin (III) has been obtained and characterized for the first time.All-Union Scientific-Research Institute of Medicinal Plants, Moscow. Irkutsk Institute of Organic Chemistry, Siberian Branch of the Academy of Sciences of the USSR. M. M. Sechenov First Moscow Medical Institute. Translated from Khimiya Prirodnykh Soedirenii, No. 5, pp. 570–576, September–October, 1978.     

O-acylated flavonoid glycosides of the needles ofPinus sylvestris III. Di-p-coumaroyltrifolin

Summary A new diacylated flavonol glycoside has been isolated for the first time from Scotch pine needles, and for it the structure of 3,4,5,7-tetrahydroxyflavone 3-0-(3,6-di-O-p-coumaroyl--D-galactopyranoside) has been established.In the course of the chemical study of the compound isolated, the previously undescribed 6-O-p-coumaroyltrifolin was isolated and characterized.All-Union Scientific-Research Institute of Medicinal Plants, Moscow. Irkutsk Institute of Organic Chemistry, Siberian Branch of the Academy of Sciences of the USSR. I. M. Sechenov First Moscow Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 332–336, May–June, 1978.     

Use of a Scanner and Digital Image-Processing Software for the Quantification of Adsorbed Substances

The possibility of using a desktop scanner and digital image-processing software for the numerical evaluation of the color intensity of substances adsorbed on polyurethane foam is studied. The method is based on scanning colored samples of polyurethane foam using a desktop scanner, processing the color images using Adobe Photoshop as a graphics editor, and building calibration plots of the luminosity of the selected channel (R, G, or B) as a function of the concentration of the test compound using the Origin software. It has been found that the calibration plots are described by a first-order exponential decay function. The advantages of the method are its high performance, rapidity, and the possibility of mathematical processing of the results. It has been found that substances adsorbed on polyurethane foam can be determined with the use of a scanner and the corresponding image-processing software with the same sensitivity as with the use of diffuse-reflectance spectroscopy.     

Platinum(IV)-mediated nitrile-sulfimide coupling: a route to heterodiazadienes

Pt(IV)-mediated addition of the sulfimide Ph2S = NH and the mixed sulfide/sulfimides o- and p-[PhS(=NH)](PhS)-C6H4 by the S=NH group to the metal-bound nitriles in the platinum(IV) complexes [PtCl4(RCN)2] proceeds smoothly at room temperature in CH2Cl2 and results in the formation of the heterodiazadiene compounds [PtCl4[NH=C(R)N=SR'Ph]2] (R' = Ph, R = Me, Et, CH2Ph, Ph; R' = o- and p-(PhS)C6H4; R = Et). While trans-[PtCl4(RCN)2] (R = Et, CH2Ph, Ph) reacting with Ph2S=NH leads exclusively to trans-[PtCl4[NH=C(R)N=SPh2]2], cis/trans-[PtCl4(MeCN)2] leads to cis/trans mixtures of [PtCl4[NH=C(Me)N=SPh2]2] and the latter have been separated by column chromatography. Theoretical calculations at both HF/HF and MP2//HF levels for the cis and trans isomers of [PtCl4[NH=C(Me)N=SMe2]2] indicate a higher stability for the latter. Compounds trans-[PtCl4[E-NH=C(R)N=SPh2]2] (R = Me, Et) and cis-[PtCl4[E-NH=C(Me)N=SPh2][Z-NH=C(Me)N=SPh2]] have been characterized by X-ray crystallography. The complexes [PtCl4[NH=C(R)N=SPh2]2] undergo hydrolysis when treated with HCl in nondried CH2Cl2 to achieve the amidines [PtCl4[NH=C(NH2)R]2] the compound with R = Et has been structurally characterized) and Ph2SO. The heterodiazadiene ligands, formed upon Pt(IV)-mediated RCN/sulfimide coupling, can be liberated from their platinum(IV) complexes [PtCl4[NH=C(R)N=SR'Ph]2] by reaction with Ph2PCH2CH2PPh2 (dppe) giving free NH=C(R)=SR'Ph and the dppe oxides, which constitutes a novel route for such rare types of heterodiazadienes whose number has also been extended. The hybrid sulfide/sulfimide species o- and p-[PhS(=NH)](PhS)C6H4 also react with the Pt(II) nitrile complex [PtCl2(MeCN)2] but the coupling--in contrast to the Pt(IV) species--gives the chelates [PtCl2[M-I=C(Me)N=S(Ph)C6H4SPh]]. The X-ray crystal structure of [PtCl2[M-I=C(Me)N=S(Ph)C6H4SPh-o]] reveals the bond parameters within the metallacycle and shows an unusual close interaction of the sulfide sulfur atom with the platinum.     

The first examples of metal-mediated addition of a phosphorus imine to nitriles; the preparation and X-ray crystal structures of [PtCl4{NH=C(Et)N=PPh3}2] and [PtCl2(EtCN){NH=C(Et)N[double bond, length as m-dash]PPh3}

Imino(triphenyl)phosphorane, Ph3P=NH (1), reacts with nitrile complexes of Pt(IV) to generate hydrolytically sensitive [PtCl4{NH=C(R)N=PPh3}2](R=Me 2a, Et 2b, Ph 2c), and with the Pt(II) complex [PtCl2(EtCN)2] to give [PtCl2(EtCN){NH=C(Et)N=PPh3}](3) and [PtCl2{NH=C(Et)N=PPh3}2](4); X-ray crystallography performed upon (2b) and (3) confirms the presence of an imine/nitrile addition ligand bound by the terminal nitrogen.     

Anodic behavior of stainless steels in electrochemical synthesis of graphite bisulfate

Anodic-corrosion behavior of a number of chromium-nickel steels in a 80% H₂SO₄ solution was studied in order to replace platinum with less expensive electrodes in electrochemical synthesis of graphite bisulfite and corrosion parameters were determined.