Application of biosynthetic 13C-enrichment using [1-13C]-, [2-13C]- and [1,2-13C2]-acetate as precursor for 13C NMR spectral assignment of higher plant metabolites. The assignments of some bryonolic acid derivatives

The ¹³C NMR spectra of some derivatives of bryonolic acid (1) (D:C-friedoolean-8-en-3β-ol-29-oic acid) were assigned by means of ¹³C-enrichment, lanthanide-induced shifts (LIS) and comparison of chemical shift data between derivatives. The ¹³C-enriched species of 1, i.e., 1a, 1b and 1c were biosynthesized by Luffa cylindrica (Cucurbitaceae) callus fed with [1-¹³C]-, [2-¹³C]- or [1,2-¹³C₂]-acetate, respectively. Methyl acetylbryonolates 2, 2a, 2b and 2c, methyl bryonolates 3, 3a, 3b and 3c, methyl bryononates 4 and 4a, diacetyl-3β,29-diols (3,29-diacetyl-D:C-friedoolean-8-en-β,29-diol) 5, 5a, 5b and 5c, and 3-acetyl-3β,29-diols 6, 6a and 6b were prepared from 1, 1a, 1b and 1c, and their ¹³C NMR spectra were recorded. The ¹³C concentration of the ¹³C-enriched species was high enough to exhibit the satellite peaks clearly, and the analysed data were very useful for this study. Thus, total assignments for 2, 3, 4, 5 and 6 were established. It was found that conversion of the methoxycarbonyl group at C-29 into an acetoxymethyl group caused complex changes in the chemical shifts of the C, D- and E-ring carbons and those of the methyl carbons linked to these rings.     

Powers of positive elements in C*‐algebras

In this paper, we show that Ogasawa’s theorem has a proof in Bishop style constructive mathematics (BISH). In 25 , we introduced the elementary constructive theory of C*‐algebras in BISH, but we did not discuss the powers of positive elements there. © 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim     

Elemental Selenium Generated by the Photobleaching of Seleno-Merocyanine Photosensitizers Forms Conjugates with Serum Macro-Molecules That are Toxic to Tumor Cells

Abstract

Elemental selenium generated by the photobleaching of selenomerocyanine dyes forms conjugates with serum albumin and serum lipoproteins that are toxic to leukemia and selected solid tumor cells but well tolerated by normal CD34-positive hematopoietic stem and progenitor cells. Serum albumin and lipoproteins act as Trojan horses that deliver the cytotoxic entity (elemental selenium) to tumor cells as part of a physiological process. They exploit the fact that many tumors have an increased demand for albumin and/or low-density lipoprotein. Se(0)-protein conjugates are more toxic than selenium dioxide, sodium selenite, selenomethionine, or selenocystine. They are only minimally affected by a drug resistance mechanism, and they potentiate the cytotoxic effect of ionizing radiation and several standard chemotherapeutic agents. The cytotoxic mechanism of Se(0)-protein conjugates is not yet fully understood. Currently available data are consistent with the notion that Se(0)-protein conjugates act as air oxidation catalysts that cause a rapid depletion of intracellular glutathione and induce apoptosis. Drugs modeled after our Se(0)-protein conjugates may prove useful for the local and/or systemic therapy of cancer.     

Determination of purine contents of alcoholic beverages using high performance liquid chromatography

The purine contents of alcoholic beverages were determined in order to utilize them in the dietary care of gout and hyperuricemia. In the management of these diseases, restriction of both alcohol and purine intake are important. The method employed in this study is a quantitative determination of purine contents by HPLC. Alcoholic beverages were hydrolyzed to corresponding purine bases, which were then separated by HPLC, and base peaks were identified using an enzymatic peak‐shift technique. This method is sufficiently accurate and reproducible to examine the purine contents of various alcoholic beverages that patients consume. Purine contents were as follows: spirits, 0.7–26.4 µmol/L; regular beer, 225.0–580.2 µmol/L; low‐malt beer, 193.4–267.9 µmol/L; low‐malt and low‐purine beer, 13.3 µmol/L; other liquors, 13.1–818.3 µmol/L. Some local and low‐alcohol beers were found to contain about 2.5 times more purines than regular beer. As some alcoholic beverages contain considerable amounts of purines, we recommend that excess consumption of these beverages be avoided. These data should be useful in the management of hyperuricemia and gout, not only for patients but also for physicians. Copyright © 2009 John Wiley & Sons, Ltd.     

Blow-up theorem for semilinear wave equations with non-zero initial position

One of the features of solutions of semilinear wave equations can be found in blow-up results for non-compactly supported data. In spite of finite propagation speed of the linear wave, we have no global in time solution for any power nonlinearity if the spatial decay of the initial data is weak. This was first observed by Asakura (1986) [2] finding out a critical decay to ensure the global existence of the solution. But the blow-up result is available only for zero initial position having positive speed.In this paper the blow-up theorem for non-zero initial position by Uesaka (2009) [22] is extended to higher-dimensional case. And the assumption on the nonlinear term is relaxed to include an example, |u|^p−1u. Moreover the critical decay of the initial position is clarified by example.     

Stereocontrolled synthesis of the macrolactone core of neopeltolide

A stereoselective synthesis of the macrolactone core of neopeltolide is described. The tetrahydropyran moiety was constructed via the intramolecular allylation of an α-acetoxy ether. A late-stage macrolactonization provided a known synthetic intermediate of neopeltolide.     

Platinum nanoparticle induced nanoionic effects on electrical conduction in strontium cerate and zirconate

Journal of Solid State Electrochemistry - Heterointerfaces introduce unique localized defects into ionic conductors. This study explores the nanoionic characteristics exhibited by the...