Newly found K-Thioflavin T competitive binding to DNA G-quadruplexes and the development of a label-free fluorescent biosensor with extra low detection limit for K determination in urine samples.

The determination of potassium ion K in body fluids is important in health monitoring and diagnoses. One of the interesting and simple methods for K detection is the use of label-free biosensors based on DNA G-quadruplexes (GQs) coupled with a specific fluorescent probe, such as Thioflavin T (ThT), which lights up when bound with K-stabilized GQs. However, these biosensors are not generally sensitive.

Magnetic microsphere sorbent on CaCO templates: Simple synthesis and efficient extraction of trace carbamate pesticides in fresh produce.

Polypyrrole magnetic microspheres were synthesized and used to extract carbaryl, carbofuran, and methomyl before analysis by a high-performance liquid chromatography with diode array detection. Under optimal conditions, four times the preconcentration was achieved with the use of only 1.2 mL of sample.

A novel 3D-printed solid phase microextraction device equipped with silver-polyaniline coated pencil lead for the extraction of phthalate esters in cosmeceutical products.

A screw-based portable and simple solid phase microextraction device was fabricated by a 3D printer and used in combination with the developed silver-incorporated porous polyaniline film pencil lead solid-phase microextraction fiber (Ag/PANI SPME). Scanning electron microscopy revealed a porous structure of the electrodeposited Ag/PANI film. The spectrum from energy dispersive x-ray spectroscopy (EDS) and the elemental map confirmed the presence of silver in the porous polymer film.

L655,240, acting as a competitive BACE1 inhibitor, efficiently decreases β-amyloid peptide production in HEK293-APPswe cells.

Aim: To identify a small molecule L655,240 as a novel β-secretase (BACE1) inhibitor and to investigate its effects on β-amyloid (Aβ) generation in vitro.

Methods: Fluorescence resonance energy transfer (FRET) was used to characterize the inhibitory effect of L655,240 on BACE1. Surface plasmon resonance (SPR) technology-based assay was performed to study the binding affinity of L655,240 for BACE1.

Tetrahydroanthraquinone and xanthone derivatives from the marine-derived fungus Trichoderma aureoviride PSU-F95.

Trichodermaquinone (1) and trichodermaxanthone (2) were isolated from the marine-derived fungus Trichoderma aureoviride PSU-F95 together with eleven known compounds. The structures were interpreted by spectroscopic methods. Known coniothranthraquinone 1 and emodin displayed strong antibacterial activity against methicillin-resistant Staphylococcus aureus with the MIC values of 8 and 4 μg/mL, respectively.

Sesquiterpene and xanthone derivatives from the sea fan-derived fungus Aspergillus sydowii PSU-F154.

Three new sesquiterpenes, named aspergillusenes A and B and (+)-(7S)-7-O-methylsydonic acid, and two new hydrogenated xanthone derivatives, named aspergillusones A and B, were isolated from the sea fan-derived fungus Aspergillus sydowii PSU-F154 together with 10 known compounds. Their structures were identified on the basis of spectroscopic data. The isolated compounds were evaluated for their antioxidant activity.

Synthesis and conformational analysis of cyclic analogues of inverse gamma-turns.

Gamma-turn analogues comprising a modified dipeptide constrained in an eleven-membered ring were prepared by alkene metathesis and analysed by NMR and molecular modelling studies. The results reveal that some of the cyclic analogues form inverse gamma-turns and preferentially adopt conformations determined by the identity of the incorporated amino acid residues and the nature of the constraining linker (E/Z-alkene or alkane).