Three new matrine-type alkaloids, (+)-5α-hydroxyoxysophocarpine (1), (-)-12β-hydroxyoxysophocarpine (2), and (+)-5α-hydroxylemannine (3), along with 14 known analogues, (-)-sophocarpine (4), (-)-5α-hydroxysophocarpine (5), (-)-9α-hydroxysophocarpine (6), (+)-12α-hydroxysophocarpine (7), (-)-12β-hydroxysophocarpine (8), (+)-oxysophocarpine (9), (+)-matrine (10), (+)-sophoranol (11), (+)-9α-hydroxymatrine (12), (-)-14β-hydroxymatrine (13), (+)-oxymatrine (14), (+)-5α-hydroxyoxymatrine (15), (-)-14β-hydroxyoxymatrine (16), and (+)-sophoramine (17), were isolated from the rhizomes of Sophora tonkinensis. Their structures were elucidated via spectrometric data analyses, and the absolute configurations were established by single-crystal X-ray diffraction and ECD data. Alkaloids 2, 6, 11, and 13 exhibited antiviral activity against the Coxsackie virus B3 (CVB3), with IC50 values of 26.62-252.18 μM, and alkaloids 7, 8, and 17 inhibited influenza virus A/Hanfang/359/95 (H3N2) replication with IC50 values of 63.07-242.46 μM.

An artificial metalloenzyme (BSA-CoL) based on the incorporation of a cobalt(ii) Schiff base complex {CoL, H2L = 2,2'-[(1,2-ethanediyl)bis(nitrilopropylidyne)]bisphenol} with bovine serum albumin (BSA) has been synthesized and characterized. Attention is focused on the catalytic activity of this artificial metalloenzyme for enantioselective oxidation of a variety of sulfides with H2O2. The influences of parameters such as pH, temperature, and the concentration of catalyst and oxidant on thioanisole as a model are investigated. Under optimum conditions, BSA-CoL as a hybrid biocatalyst is efficient for the enantioselective oxidation of a series of sulfides, producing the corresponding sulfoxides with excellent conversion (up to 100%), chemoselectivity (up to 100%) and good enantiomeric purity (up to 87% ee) in certain cases.

The first example of rare earth metal-catalyzed [3 + 2] cycloaddition of organic azides with nitroolefins and subsequent elimination reaction is described. In the presence of a catalytic amount of Ce(OTf)3, both benzyl and phenyl azides react with a broad range of aryl nitroolefins containing a range of functionalities selectively producing 1,5-disubstituted 1,2,3-triazoles in good to excellent yields.

To systematically investigate the influence of the positional isomeric ligands on the structures and magnetic properties of their complexes, we synthesized ten Co(II) complexes with three positional isomeric dipyridyl ligands (4,4′-bpt, 3,4′-bpt and 3,3′-bpt), as well as the phenyl dicarboxylate anions, namely, [Co(o-BDC)(4,4′-bpt)(H2O)] (1), [Co(o-BDC)(3,3′-bpt)(H2O)] (2), [Co(3-Cl-o-BDC)(4,4′-bpt)(H2O)] (3), [Co(3-Cl-o-BDC)(3,4′-bpt)] (4), [Co(m-BDC)(3,4′-bpt)] (5), [Co(m-BDC)(3,3′-bpt)]·H2O (6), [Co2(5-NO2-m-BDC)2(3,4′-bpt)(H2O)4] (7), [Co(5-NO2-m-BDC)(3,3′-bpt)]·H2O (8), [Co(p-BDC)(3,4′-bpt)2(H2O)2]·2H2O (9), and [Co(p-BDC)(3,3′-bpt)2(H2O)2]·2H2O (10) (o-BDC = 1,2-benzenedicarboxylate anion, 3-Cl-o-BDC = 3-Cl-1,2-benzenedicarboxylate anion, m-BDC = 1,3-benzenedicarboxylate anion, 5-NO2-m-BDC = 5-NO2-1,3-benzenedicarboxylate anion, p-BDC = 1,4-benzenedicarboxylate anion). Structural analysis reveals that the phenyl dicarboxylate anions display versatile coordination modes to manage the Co(II) ions to form 1-D chains or 2-D layers, which are further extended via the isomeric bpt connectors in different directions, to give rise to a variety of coordination polymers, such as 2-D square 44-sql layer (for 1−5), 3-D CsCl net (for 6), 2-D honeycomb 63-hcb layer (for 7), 1-D double chain (for 8), and 1-D decorated chain (for 9−10). This work indicates that the isomeric effects of the bpt ligands are significant in the construction of these network structures, based on same Co(II) centers. Furthermore, these compounds exhibit different magnetic behaviors. In 1−3, although Co(II) ions have the similar structural characteristic, the phenomenon of spin-canting in 2 can be observed more easily than 1 and 3, which may reveal that the different orientations of the pyridyl groups in bpt isomer have a profound impact on the magnetic properties of the solids. In 4, 5, and 7, which all are bridged by asymmetric 3,4′-bpt ligand, spin-canting in 7 can be observed more easily than 4 and 5 because the adjacent Co(II) ions are related to a inversion center in 4 and 5. Moveover, there are approximate isotropic Co(II) ions in 4. In addition, the magnetic behavior of compounds 6 and 8 was also studied and indicated the existence of antiferromagnetic interactions.

In this study, two Ni(II) complexes, namely [Ni(HL1)2(OAc)2] (1) and [Ni(L2)2] (2) (where HL1 and HL2 are (E)-1-((1-(2-hydroxyethyl)-1H-pyrazol-5-ylimino)methyl)-naphthalen-2-ol) and (E)-ethyl-5-((2-hydroxynaphthalen-1-yl)methyleneamino)-1-methyl-1H-pyrazole-4-carboxylate, respectively), were synthesized and characterized by X-ray crystallography, Electrospray Ionization Mass Spectrometry (ESI-MS), elemental analysis, and IR. Their uptake in biological macromolecules and cancer cells were preliminarily investigated through electronic absorption (UV-Vis), circular dichroism (CD) and fluorescence quenching measurements. Bovine serum albumin (BSA) interaction experiments were investigated by spectroscopy which showed that the complexes and ligands could quench the intrinsic fluorescence of BSA through an obvious static quenching process. The spectroscopic studies indicated that these complexes could bind to DNA via groove, non-covalent, and electrostatic interactions. Furthermore, in vitro methyl thiazolyl tetrazolium (MTT) assays and Annexin V/PI flow cytometry experiments were performed to assess the antitumor capacity of the complexes against eight cell lines. The results show that both of the complexes possess reasonable cytotoxicities.