Detection of short oligonucleotide sequences of hepatitis B virus using electrochemical DNA hybridisation biosensor

A novel, sensitive and selective electrochemical hybridisation biosensor was developed for the detection of the hepatitis B virus (HBV) using a manganese(II) complex as electrochemical indicator and a DNA probe-modified carbon paste electrode as the biosensor (DNA/CPE). The results showed that this complex could be accumulated electrochemically the immobilised dsDNA layer rather than in the single-stranded DNA (ssDNA) layer. On the basis of this, the manganese complex was used as an electrochemical hybridisation indicator for the detection of oligonucleotides related to HBV. The hybridisation event was evaluated on the basis of the difference between the reduction signals of the manganese(II) complex with the probe DNA prior to and post hybridisation with a target sequence using a differential pulse mode. Several factors affecting the immobilisation and hybridisation of oligonucleotides as well as the indicator’s accumulation were investigated. Experiments with a non-complementary and mismatch sequences demonstrated the good selectivity of the biosensor. Using this approach, the HBV target oligonucleotide’s sequence could be quantified over arange from 0.22 ng L^?1 to 5.40 ng L^?1, with a linear correlation coefficient of 0.9994 and the limit of detection of 0.07 ng L^?1.     

CYP505E3: A Novel Self-Sufficient ω-7 In-Chain Hydroxylase

The self-sufficient cytochrome P450 monooxygenase CYP505E3 from Aspergillus terreus catalyzes the regioselective in-chain hydroxylation of alkanes, fatty alcohols, and fatty acids at the ω-7 position. It is the first reported P450 to give regioselective in-chain ω-7 hydroxylation of C10–C16 n-alkanes, thereby enabling the one step biocatalytic synthesis of rare alcohols such as 5-dodecanol and 7-tetradecanol. It shows more than 70 % regioselectivity for the eighth carbon from one methyl terminus, and displays remarkably high activity towards decane (TTN≈8000) and dodecane (TTN≈2000). CYP505E3 can be used to synthesize the high-value flavour compound δ-dodecalactone via two routes: 1) conversion of dodecanoic acid into 5-hydroxydodecanoic acid (24 % regioselectivity), which at low pH lactonises to δ-dodecalactone, and 2) conversion of 1-dodecanol into 1,5-dodecanediol (55 % regioselectivity), which can be converted into δ-dodecalactone by horse liver alcohol dehydrogenase.     

Prospects and challenges in designing photocatalytic particle suspension reactors for solar fuel processing

Photocatalytic approaches for the production of solar hydrogen or hydrocarbons are interesting as they provide a sustainable alternative to fossil fuels. Research has been focused on water splitting and on the synthesis of photocatalyst materials and compounds, and their characterization. The material-related challenges include the synthesis and design of photocatalysts that can absorb visible light at a high quantum efficiency, cocatalysts that are selective and can accelerate the reduction and/or oxidation reactions, and protection layers that facilitate migration of the minority carriers to the surface-active sites while reducing charge recombination and photo-corrosion. Less attention has been paid to the conceptual design of reactors, and how design and coupled transport can affect the material choice and requirements. This perspective discusses the various possible conceptual designs for particle suspension reactors and the related implications on the material requirements to achieve high energy conversion efficiencies. We establish a link between the thermodynamic limits, materials requirements, and conceptual reactor designs, quantify changes in material requirements when more realistic operation and losses are considered, and compare the theory-derived guidelines with the ongoing materials research activity.

This perspective discusses the various possible conceptual designs for particle suspension reactors and the related implications on the material and reactor requirements to achieve high STH conversion efficiencies.     

Selective and multiple functionalization of pyridines and alkaloids via Mg- and Zn-organometallic intermediates

Quinine, nicotine, and related electron-rich amino-substituted pyridines were readily metalated using LiCl-solubilized TMP (2,2,6,6-tetramethylpiperidyl) bases in the presence of BF(3)·OEt(2). A full pyridine functionalization of all five positions of the pyridine ring can be realized by using an appropriate combination of TMP bases in the presence or absence of BF(3)·OEt(2).     

Synthesis of the hydroxide cluster [Al13(μ3-OH)6(μ-OH)18(H2O)24]15+ from an aqueous solution

A scalable synthesis of the "flat" tridecameric inorganic cluster [Al(13)(μ(3)-OH)(6)(μ-OH)(18)(H(2)O)(24)](15+) has been realized by treating an aqueous aluminum nitrate solution with a zinc-metal powder at room temperature. Single crystals and polycrystalline samples are readily obtained in yields exceeding 55% relative to the starting reagent Al(NO(3))(3). Products have been characterized by X-ray diffraction and solid-state (27)Al MAS and MQMAS NMR.     

Catching gaseous SO2 in cone-type lanthanide complexes: an unexpected coordination mode for SO2 in f-element chemistry

Easy come, easy go: the first molecular SO(2) complexes of the lanthanides (Ln=Sm, Eu) have been prepared. The compounds can reversibly coordinate gaseous SO(2). Concomitant with the addition and removal of SO(2), the color of the complexes changes reversibly. The structures of the SO(2) compounds could be confirmed in solution and in the solid state.     

A Novel Synthesis of Salvadoricine Schiff Bases

Treatment of the readily available l-methylpyrano[3,4-b]indol-3-one with primary aromatic amines leads directly to the formation of Schiff bases of the indole alkaloid Salvadoricine (2-acetyl-3-methyl-indole).