[Acyclic nucleotide analogues based on phosphonic acids]

The synthesis of novel nucleotide analogues on the basis of ethylphosphonic acid was described. A rigid structural element, an amide or a double bond, was characteristics of the compounds synthesized. The antiviral and cytotoxic activities of these compounds were studied in cell cultures.

Structure of the capsular polysaccharide from Alteromonas nigrifaciens IAM 13010T containing 2-acetamido-2,6-dideoxy-L-talose and 3-deoxy-D-manno-octulosonic acid

A capsular polysaccharide was obtained from Alteromonas nigrifaciens IAM 13010T by saline extraction. On the basis of 1H and 13C NMR spectroscopy, including one-dimensional (1D) NOE spectroscopy, 2D rotating-frame NOE spectroscopy (ROESY), and 1H-detected heteronuclear 1H,13C multiple-quantum coherence (HMQC), it was concluded that the polysaccharide contained inter alia an acidic sugar, 3-deoxy-D-manno-octulosonic acid (Kdo), and a rare amino sugar, 2-acetamido-2,6-dideoxy-L-talose (L-6dTalNAc, N-acetylpneumosamine), and has a pentasaccharide repeating unit of the following structure: [equation: see text]

[The interaction of organophosphorus amino acid analogs with cytochrome P-450 2B4]

Interaction between phosphorus amino acids analogs, 1-aminoalkylphosphonous and 1-aminoalkylthiophosphonic acids, and microsomes from the liver of phenobarbital-induced rabbits was studied. The phosphorus amino acids analogs cause type I and reverse type I spectral changes, respectively. A new reaction in the microsomal monooxygenase system was revealed. In the presence of NADPH, 1-aminoalkylphosphonous acids can be transformed to the corresponding 1-aminoalkylphosphonic acids by the reaction P-H-->P-OH. The reaction was monitored by 1H-NMR spectroscopy. 1-Aminoalkylphosphonous acids also serve as substrates for the NADPH-dependent monooxygenase system. 31P-NMR has shown that the oxidative desulfuration produces 1-aminoalkylphosphonous acids according to the reaction P=S-->P=O. Neither 1-aminoalkylphosphonous nor 1-aminoalkylphosphonic acids are deaminated in the NADPH-dependent monooxygenase system as follows from 1H-NMR spectroscopy.

Interaction of organophosphorus analogues of amino acids with P450

1. This study deals with the oxidation of organophosphorus amino acid analogues by phenobarbital-induced rabbit liver microsomes. It has been shown that 1-aminoalkylphosphonous and 1-aminoalkylthiophosphonic acids are converted by P450 to 1-aminoalkylphosphonic acids. 2. Phosphonous analogues of amino acids cause type I spectral changes, and thiophosphonic analogues produce reverse type I changes in different spectra. 3. In the presence of NADPH, the 1-aminoalkylphosphonous acids form the corresponding 1-aminoalkylphosphonic acids by the reaction P-H-->P-OH, as monitored using 1H nmr spectroscopy. 4. Aminoalkylthiophosphonic acids have also proven to be the substrates for the NADPH-dependent monoxygenase system. During the course of oxidative desulphuration 1-aminoalkylphosphonic acids were formed by the reaction P = S-->P = O, as monitored by 31P-nmr spectroscopy. 5. Using resonance Raman (RR) spectroscopy, the interaction of 1-aminoisobutyl-phosphonous acid with P450 was investigated, and characteristic changes in spectral frequencies in the region between 1370 and 1700 cm-1 were demonstrated. These latter changes indicate that substrate binding of organophosphorus compounds leads to alterations in haem conformation and to redistribution of the electron density.