Transport of Nucleoside Triphosphates into Cells by Artificial Molecular Transporters

Chemically modified nucleoside triphosphates (NTPs) are widely exploited as unnatural metabolites in chemical biology and medicinal chemistry. Because anionic NTPs do not permeate cell membranes, their corresponding neutral precursors are employed in cell‐based assays. These precursors become active metabolites after enzymatic conversion, which often proceeds insufficiently. Here we show that metabolically‐active NTPs can be directly transported into eukaryotic cells and bacteria by the action of designed synthetic nucleoside triphosphate transporters (SNTTs). The transporter is composed of a receptor, which forms a non‐covalent complex with a triphosphate anion, and a cell‐penetrating agent, which translocates the complex across the plasma membrane. NTP is then released from the complex in the intracellular milieu and accumulates in nuclei and nucleoli in high concentration. The transport of NTPs proceeds rapidly (seconds to minutes) and selectively even in the presence of other organic anions. We demonstrate that this operationally simple and efficient means of transport of fluorescently labelled NTPs into cells can be used for metabolic labeling of DNA in live cells.     

The investigation on phytochemicals from Ferulago angulata (Schlecht) Boiss,indigenous to central parts of Iran

Ferulago angulata (Schlecht) Boiss (Apiaceae) is a perennial herb distributed in the central parts of Iran. In this work, the essential oil of Ferulago angulat a aerial parts collected from the central parts of Iran was obtained by using hydrodistillation analysed by GC and GC–MS. Air-dried and powdered plant roots were extracted with n-hexane, dichloromethane and methanol, respectively, using a Soxhlet apparatus. The n-hexane extract was subjected to preparative thin-layer chromatography using chloroform–acetone (95:5) as solvent system to yield two linear furanocoumarins, prantschimgin and oxypeucedanin. The structure of theisolated compounds was elucidated by using spectroscopic data such as ¹H NMR, ¹³C NMR, UV and IR. The results of GC–MS analyses showed that γ-terpinolene (11.97%), α-pinene (10.00%), sabinene (6.89%), linalool (5.56%) and cis-ocimene (4.41%) were the main components among 51 constituents characterised in the oil. The oil exhibits considerable phytotoxic activity.     

Per-2,3-O-alkylated β-cyclodextrin duplexes connected with disulfide bonds

Per-2,3-di-O-methyl- and per-2,3-di-O-allyl-β-cyclodextrin duplexes held by two disulfide bonds between their primary faces have been prepared. Permethylation significantly increased the solubility of the cyclodextrin duplexes in a wide range of solvents from water to chlorinated hydrocarbons. Per-2,3-di-O-methylated duplexes are able to form inclusion complexes with organic molecules in aqueous solutions, yet the stability constants are lower by 4–5 orders of magnitude as compared to analogous non-alkylated β-cyclodextrin duplexes.     

Trifluoromethylated (tetrahydropyrrolo) quinazolinones by a new three‐component reaction and facile assignment of the regio‐ and stereoisomers formed by NMR spectroscopy

A new three‐component cyclisation reactions of methyl 3,3,3‐trifluoropyruvate, 2‐aminobenzylamine and oxo compounds afforded tetrahydropyrroloquinazolinones of the types 4 and 5 as mixtures of regio‐ and stereoisomers. Whereas standard 1D NMR spectroscopy was used for a facile assignment of the cyclization regioisomers, a combination of homo (proton–proton) and heteronuclear (proton–fluorine) NOE experiments allowed the determination of the relative configuration on stereogenic centres. The structure of some compounds was also confirmed by the X‐ray diffraction. Adaptation of the 1D double‐pulsed field‐gradient spin‐echo NOE for a heteronuclear case is presented. Copyright © 2010 John Wiley & Sons, Ltd.