Partialsynthetische Aristolochiasäuren und Analoge 4. Mitt.: 3,4,5,6-Tetramethoxy-1,8-dinitrophenanthren, 3,4,5,6-Tetramethoxy-8-nitro- und 3,4,5,6-Tetramethoxy-8,10-dinitrophenanthren-1-carbonsäuren

An aporphine alcaloid of the bulbocapnine-type (isocorydine) was used for the synthesis of aristolochic acid analogs. By degradation and nitration of the reaction product three new compounds, a dinitrophenanthrene, a nitro- and a dinitrophenanthrene acid were obtained and their structures were established.

     

HPLC enantioseparation of phenylalanine analogs by application of (S)-N-(4-nitrophenoxycarbonyl)phenylalanine methoxyethyl ester as a new chiral derivatizing agent

Summary The indirect stereochemical resolution of the enantiomers of phenylalanine analogs was studied by high-performance liquid chromatographic methods. The resolution was performed by applying pre-column derivatization with (S)-N-(4-nitrophenoxycarbonyl)phenylalanine methoxyethyl ester, (S)-NIFE, as a new chiral derivatizing agent. Its applicability is demonstrated by the derivatization and separation of a series of ring-and α-methyl-substituted phenylalanines and phenylalanine amides, and especially by the derivatization of sterically hindered, less reactive α-methyl-substituted phenylalanine analogs. The diastereomeric, derivatives produced were separated by reversed-phase high-performance liquid, chromatography. The conditions of both derivatization and separation were optimized. The method described offers good enantioselectivity for various chiral amino compounds derived from chemo-enzymatic processes.     

Using theozymes for designing transition‐state analogs for the intramolecular aldol reaction of δ‐diketones

Two theozymes for the intramolecular aldol reaction of δ‐diketones have been studied using ab initio methods. The presence of both acid/base residues favors several steps of the aldol reaction. The appropriate positioning of these residues can accelerate one of two diastereromeric reaction pathways, the catalyzed aldol reaction being highly stereoselective. Analysis of the geometrical parameters, charge distribution, and the shape of molecular electrostatic potential for the corresponding acid/base catalyzed transition structure allows us to design adequate transition‐state analogs to favor a reactive channel of this intramolecular aldol reaction. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 83: 338–347, 2001     

Synthetic analogs of naturally occurring flavolignans. XI. Reaction of synthetic flavone analogs with hydrazine hydrate and its derivatives

Reactions of 1,3-benzodioxane and 1,4-benzodioxane analogs of flavones with hydrazine derivatives are studied. The hydrazines recyclize the new flavones into 3,5-diarylpyrazoles. Their PMR spectra confirm their structures.Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 40–41, January–February, 2000.     

A solid phase approach to PDMP analogs：A general strategy for combinatorial library

The present work reports the first solid phase synthesis of biologically interesting D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol(D-threo-PDMP)derivatives.This synthetic strategy includes facile preparation of versatile azido intermediate(5) in a relatively short sequence and the subsequent derivatization of 5,which led to a series of sulfonamide,urea and heterocycle substituted PDMP analogs(10 and 10’).With this method,a 5280-member compound library has been successfully built by IRORI Nanokan? system.     

Novel stilbene‐based Fischer base analog of leuco‐TAM – (2E,2′Z)‐{2‐(4‐(E)‐styrylphenyl)propane‐1,3‐diylidene}bis(1,3,3‐trimethylindoline) – derivatives: synthesis and structural consideration by 1D NMR and 2D NMR spectroscopy

We report the synthesis of a series of novel stilbene‐based (St) Fischer base analogs of leuco‐triarylmethane (LTAM) dyes by treating Fischer base with (E)‐4‐styrylbenzaldehyde derivatives. All St‐LTAM molecules examined herein are characterized by 1D and 2D NMR. They were found to exhibit ZE configuration and isomerize to their diastereomers EE and ZZ in 2–3 h. They exhibit type I behavior of diastereomeric isomerization. Copyright © 2015 John Wiley & Sons, Ltd.     

Structural Basis for Bulky‐Adduct DNA‐Lesion Recognition by the Nucleotide Excision Repair Protein Rad14

Heterocyclic aromatic amines react with purine bases and result in bulky DNA adducts that cause mutations. Such structurally diverse lesions are substrates for the nucleotide excision repair (NER). It is thought that the NER machinery recognises and verifies distorted DNA conformations, also involving the xeroderma pigmentosum group A and C proteins (XPA, XPC) that act as a scaffold between the DNA substrate and several other NER proteins. Here we present the synthesis of DNA molecules containing the polycyclic, aromatic amine C8‐guanine lesions acetylaminophenyl, acetylaminonaphthyl, acetylaminoanthryl, and acetylaminopyrenyl, as well as their crystal structures in complex with the yeast XPA homologue Rad14. This work further substantiates the indirect lesion‐detection mechanism employed by the NER system that recognises destabilised and deformable DNA structures.     

Gene Expression Profile of Prostate Cancer Patients by Chemiluminescent Analysis

Abstract

The heterogeneous and multifactorial nature of prostate cancer that generates differential gene expression patterns in tumor cells leads us to investigate the molecular mRNA profiling of 14 genes through streptavidin-alkaline phosphatase–labeled RNA probes from tissue samples with prostate cancer and benign prostatic hyperplasia. Hybridizations were performed using cDNA amplification for each gene spotted onto positively charged nylon membranes and densitometry readings. The constitutive gene GAPDH was used to normalize the data. The methods developed in this study may be applicable to the prostate cancer diagnosis using AR, CEACAM-1, DD3 (also called PCA3), OPN-1, and PSMA significant differential expression.     

Synthesis of Optically Active 1,4-Dioxane Nucleotide Analogs

Optically active nucleotide analogs were prepared that were composed of a 1,4-dioxane ring as the sugar analog to which either uracil or adenine attached together with two carboxylic ester groups, to be used as vehicles for formation of oligomers. The chiral 1,4-dioxane moiety was constructed from dimethyl L-tartrate via the corresponding (2R,3R)-dimethyl 2-O-allyl-tartrate.