Sulfur‐containing derivatives of 1,4‐naphthoquinone,part 1: Disulfide synthesis

Disulfides of 1,4‐naphthoquinone were synthesized, and different methods of their synthesis were investigated. High yields and purity of disulfides were obtained from the oxidation of thiol derivatives. The latter were prepared in high yields and purity from isothiuronic salts. The obtained disulfides are syntho‐ nes for compounds with a wide spectrum of biological activity. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:205–211, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20112     

Transformation Operators for Sturm-Liouville Operators with Singular Potentials

We construct transformation operators for Sturm-Liouville operators with singular potentials from the space W ⁻¹ ₂(0,1) and show that these transformation operators naturally appear during factorisation of Fredholm operators of a special form. Some applications to the spectral analysis of Sturm-Liouville operators with singular potentials under consideration are also given. This revised version was published online in July 2006 with corrections to the Cover Date.     

On Lebesgue Measure of Integral Self-Affine Sets

Let A be an expanding integer n×n matrix and D be a finite subset of ? ⁿ . The self-affine set T=T(A,D) is the unique compact set satisfying the equality \(A(T)=\bigcup_{d\in D}(T+d)\). We present an effective algorithm to compute the Lebesgue measure of the self-affine set T, the measure of the intersection T∩(T+u) for u∈? ⁿ , and the measure of the intersection of self-affine sets T(A,D ₁)∩T(A,D ₂) for different sets D ₁, D ₂?? ⁿ .     

Synthesis and Antibacterial and Antifungal Properties of Novel S-, N-, N,S-, and S,O-Substituted 1,4-Naphthoquinone Derivatives

Abstract

A novel series of substituted 1,4-naphthoquinone derivatives were synthesized and evaluated for their antibacterial and antifungal activity. The structures of the novel products were characterized by spectroscopic methods. Among the tested compounds, 2,2′,3,3′-alkoxy substituted naphthoquinones, S,O-substituted naphthoquinone, and N,S-substituted naphthoquinone derivatives are the most potent antifungals against C. tenuis. 2,3-Thio-2′,3′-alkoxy substituted naphthoquinones are the most effective antifungal compounds against A. niger.

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