Oximes and nitriles of cardenolides

The influence of the oximation of cardenolides and the production of 10-cyanocardenolides on their biological activity has been studied. The prefered conformation of strophanthidin 19-aldoxime has been established; it has chelate fragment as the result of the orientation in the same direction of the nitrogen atom of the oxime group and the hydroxy groups at C-3 and C-5.All-Union Scientific-Research Institute of the Chemistry and Technology of Drugs, Khar'kov. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 608–612, September–October, 1983.     

Alkaloid cardenolides

New alkaloid cardenolides have been synthesized and their biological activity has been studied. It has been established that ajmalinocardenolides possess cardiotonic and antiarrhythmic activity with a low or moderate toxicity, while cardenolides derivatives of hyoscyamine and of scopolamine have proved to be highly toxic compounds. Using fluorescent probes it has been shown that the ajmalinocardenolides are sorbed fairly strongly on liposome membranes, and they also promote the binding of calcium ions by biological membranes.All-Union Scientific-Research Institute of Drug Chemistry and Technology, Khar'kov. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 239–244, March–April, 1985.     

滇杠柳中的新强心甾内酯成份

从滇杠柳(Periploca forrestii)根茎中分得两个新强心甾内酯滇杠柳苷元A(periforgenin A)(Ia)和滇杠柳苷I(periforoside I)(2a)它们具有罕见的变形C/D环甾体骨架。化学结构分别为3β,5β-二羟基-15(14→8)abeo-(8S)-14-酮-强心甾-20(22)-烯内酯和滇杠柳苷元A3-O-β-D-葡葡吡喃糖基(1→4)-β-D-磁麻吡喃糖苷。结构鉴定采用光谱分析及化学方法。1a的结构还经X衍射予以证实。     

Esters of Vanillin and Vanillal Oximes

Vanillin and vanillal oximes 2a and 2b were used to prepare the corresponding esters 3a-k, 4a-k, and 5a-c by reaction with acyl chlorides in the presence of pyridine.     

肟的无污染氧化

No2;污染治理;二噁烷;肟的无污染氧化     

Some conformational peculiarities of cardenolides and bufadienolides

Summary 1. The capacity of the cardenolides and bufadienolides of the A/B-trans series having an aldehyde group at C₁₀ for giving a semiacetal form is due to the conformational features of ring A, which may be present in a chairboat equilibrium.2. The aldehyde group of strophanthidin does not participate in the formation of an intramolecular hydrogen bond with the hydroxyl group at C₃ and C₅; an intramolecular hydrogen bond occurs between the hydroxyl groups at C₃ and C₅.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 3, pp. 179–184, 1966     

Phosphorylation of Polyacrolein Oximes

Esterification of polyacrolein oximes with phosphorus pentoxide in DMF at 100°C for 4 h gives rise to phosphoric acid esters. Solid-phase ³¹P NMR spectroscopy, IR spectroscopy and potentiometric titration were used to establish that the phosphorylation proceeds by the hydroxy group of N-hydroxypiperidine rings incorporated into the polymeric macromolecule. Formation of acrylonitrile links is not observed. The influence of water on the phosphorylation of polyacrolein oximes is studied.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 2, 2005, pp. 264–267.Original Russian Text Copyright © 2005 by Antonik, Khabibulina.     

A Simple Synthesis of Oximes

Summary. The conversion of alicyclic and aliphatic carbonyl compounds as well as aromatic aldehydes into the corresponding oximes (up to quantitative yields) was achieved by simply grinding these reactants, hydroxylamine hydrochloride and sodium hydroxide without solvent. However, this procedure was unsuccessful in the case of aromatic ketones. In this case it was necessary to add silica gel as a catalyst.     

Separation of digitalis cardenolides by HPLC

The separation of Digitalis cardenolides has been carried out by HPLC on an adsorbent column. By choice of suitable mobile phase, isocratic elution permitted resolution of mixtures of (a) aglycones, (b) secondary glycosides, and (c) primary glycosides, while gradient elution provided a means of resolving more complex mixtures of these cardiac steroids. HPLC could therefore be used in the quality control of cardiotonic drugs replacing the TLC tests for related compounds currently used, and by suitable calibration could replace the colorimetric assay procedure normally used for such drugs.     

肟的无气味硫缩醛/酮化反应

探讨了以无气味且稳定的α-羰基二硫缩烯酮(1)作为代硫醇试剂的肟(2)的硫缩醛/酮化反应. 在乙酰氯-乙醇(体积分数95%)或4-十二烷基苯磺酸(DBSA)-水体系中及回流条件下, 化合物1与肟2能有效地进行硫缩醛/酮化反应. 反应过程中未闻到硫醇的恶臭气味.     

Optical rotary dispersion and configuration in cardenolides

In accordance with the results of Weiss & ZIFFER , the ORD spectra of cardenolides with few exceptions show a distinct Cotton effect, caused by the butenolide ring. The two extrema lie at about 260 and 228 nm; the extremum at shorter wave length is very difficult to measure, and that at longer wavelength shows fine structure in dioxane. 14α,17β-cardenolides having either a hydrogen atom or a hydroxyl group at C-14 and no double bond in rings C and D show a negative Cotton effect, whereas compounds of the other three stereoisomeric types (14α,17α; 14β,17α and 14β,17β) show a positive Cotton effect. In the case of cardenolides having an oxo group, the extremum of the oxo group at shorter wavelength overlaps that of the butenolide ring at longer wavelength. In spite of this the latter extremum could still be seen distinctly in all cases investigated to date.     

Photodifluoramination of nitriles

Gas phase irradiation of N₂F₄(NF₂) in the presence of trifluoroacetonitrile, ¹⁵N-trifluoroacetonitrile, or acetonitrile resulted in the formation of products that correspond to perfluorination of the unsaturation or to conversion of the substrate to a saturated fluorocarbon. The proposed mechanism involves atomic fluorine attack on the nitrile and subsequent rearrangement of the resulting N,N-difluorohydrazone, R₂C(F)NNF₂, to an alkylfluorodiazene R₂C(F)-N=N-F. Decomposition of diazenes accounts for the observed products.