ABSTRACT
Thrombin (TB) plays a key role in the pathological and physiological coagulation of diseases. In this work, a TB-activated fluorescence-surface-enhanced Raman spectroscopy (SERS) dual-mode optical nanoprobe (MRAu) was constructed by linking rhodamine B (RB)-modified magnetic fluorescent nanospheres with AuNPs through TB-specific recognition peptides. In the presence of TB, the polypeptide substrate could specifically be cleaved by TB, resulting in the weakening of SERS hotspot effect and the reduction of Raman signal. Meanwhile, the fluorescence resonance energy transfer (FRET) system was destroyed, and the RB fluorescence signal originally quenched by AuNPs was recovered. Using MRAu, SERS and fluorescence methods were combined to extend the TB detection range to 1-150 pM, and the detection limit was as low as 0.35 pM. In addition, the ability to detect TB in human serum also verified the effectiveness and practicality of the nanoprobe. The probe was also successfully employed to evaluate the inhibitory effect against TB of active components in Panax notoginseng. This study provides a new technical means for the diagnosis and drug development of abnormal TB-related diseases.
Subject(s)
Metal Nanoparticles , Thrombin , Humans , Metal Nanoparticles/chemistry , Gold/chemistry , Spectrum Analysis, Raman/methods , Spectrometry, FluorescenceABSTRACT
A deconstructive oxygenation of unstrained primary cycloalkanamines has been developed for the first time using an auto-oxidative aromatization promoted C(sp3 )-C(sp3 ) bond cleavage strategy. This metal-free method involves the substitution reaction of cycloalkanamines with hydrazonyl chlorides and subsequent auto-oxidative annulation to in situ generate pre-aromatics, followed by N-radical-promoted ring-opening and further oxygenation by 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and m-cholorperoxybenzoic acid (mCPBA). Consequently, a series of 1,2,4-triazole-containing acyclic carbonyl compounds were efficiently produced. This protocol features a one-pot operation, mild reaction conditions, high regioselectivity and ring-opening efficiency, broad substrate scope, and is compatible with alkaloids, osamines, and peptides, as well as steroids.
ABSTRACT
A convenient and efficient vicinal oxyalkynylation/aminoalkynylation of internal unactivated alkenes is achieved by means of a Cu-catalyzed radical cascade reaction of unsaturated ketoximes with ethynylbenziodoxolone (EBX) reagents. This protocol enables the synthesis of structurally valuable isoxazolines or cyclic nitrones and the introduction of an important alkyne group in a single operation. The reaction is characterized by a broad substrate scope for both unsaturated ketoximes and alkynylation reagents and a low catalyst loading.
ABSTRACT
In the title compound, {(C(4)H(16)N(3))[La(SO(4))(3)(H(2)O)]}(n), the La atom adopts an irregular LaO(9) coordination geometry, including one bonded water mol-ecule. The three sulfate groups adopt both monodentate and bidentate coordination to the metal ions. Two of the sulfate groups serve as bridges in the (100) and (010) directions, yielding infinite sheets, whereas the third is pendant to one La(3+) cation. The protonated organic species inter-acts with the layers by way of N-Hâ¯O hydrogen bonds, and O-Hâ¯O hydrogen bonds involving aqua ligands also occur.
ABSTRACT
The title dysprosium coordination polymer, {[Dy(2)(C(10)H(8)O(6))(3)(H(2)O)(2)]·2H(2)O}(n), was synthesized by reacting dysprosium(III) nitrate and the flexible ligand (p-phenyl-enedi-oxy)diacetic acid under hydro-thermal conditions. Each Dy(III) ion is coordinated by nine O atoms in a tricapped trigonal prismatic geometry. The DyO(9) polyhedra form layers parallel to the bc plane. The rigid benzene rings of the anions link the layers along the a axis, forming a three-dimensional framework.
