RESUMO
Precise control of the structures and magnetic properties of a molecular material constitutes an important challenge to realize tailor-made magnetic function. Herein, we report that the ligand-directed coordination self-assembly of a dianionic cobalt(II) mononuclear complex and selective organic linkers has led to two distinct dicobalt(II) complexes, [Co2(pdms)2(bpym)3]·2MeCN (1) and [Co(pdms)(bipm)]2·3DMF (2) (H2pdms = 1,2-bis(methanesulfonamide)benzene; bpym = 2,2'-bipyrimidine; bimp = 1,4-bis[(1H-imidazol-1-yl)methyl]benzene). Structural analyses revealed that complexes 1 and 2 are discrete binuclear molecules containing two neutral {Co(pdms)} species bridged by bpym and bimp ligands, respectively, forming an exchange-coupled CoII2 dimer and a rare CoII2 metallocycle. Magnetic studies found that 1 exhibits considerable antiferromagnetic interactions transferred by the bpym bridge while negligible magnetic interactions in 2 due to the long bimp ligands. Interestingly, both the complexes show significant magnetic anisotropy and thus exhibit slow magnetic relaxation under an external dc field originating from spin-lattice relaxation. Detailed theoretical calculations were further applied to understand the magnetic interactions and magnetic anisotropy in 1 and 2. The foregoing results highlight that coordination solids with programmed structures and magnetic properties can be designed and prepared through a judicious selection of molecular complex building blocks and organic linkers.
RESUMO
Five undescribed phenylpropanoids, one undescribed phenolic glucoside, and sixteen known compounds were isolated from Brachybotrys paridiformis Maxim. Ex Oliv. The undescribed compounds were named brachoside B-C, brach acid A-B, brachnan A, and brachin D, respectively. Additionally, the anti-hepatitis B virus activities of all isolated compounds were studied. Among them, brachnan A, brach acid A, globoidnan A, 3-carboxy-6,7-dihydroxy-1-(3',4'-dihydroxy-phenyl)-naphthalene, and 3,4-dihydroxybenzaldehyde showed significant anti-hepatitis B virus activities.
Assuntos
Boraginaceae , Glucosídeos , Vírus da Hepatite B , Naftalenos , Extratos VegetaisRESUMO
Using chemical and spectroscopic data, this study on Brachybotrys paridiformis Maxim. ex Oliv. identified four undescribed phenylpropanoids, brachin A-C and brachoside A, together with nine other known compounds. The isolated compounds were tested for anti-hepatitis B virus activities in the HepG2.2.15 cell line. Among them, caffeic anhydride showed the most potent activity.
Assuntos
Boraginaceae , Vírus da Hepatite B , Antivirais/farmacologia , Células Hep G2 , HumanosRESUMO
Six undescribed triterpenoid saponins, named as hylomeconoside C-H, were isolated from the EtOH extract of Hylomecon japonica. On the basis of spectroscopic and chemical evidence, their structures were identified as 3-O-ß-D-galactopyranosyl-(1 â 2)-ß-D-glucuronopyranosyl gypsogenin 28-O-α-L-rhamnopyranosyl-(1 â 2)-ß-L-arabinopyranoside; 3-O-ß-D-galactopyranosyl-(1 â 2)-ß-D-glucuronopyranosyl gypsogenin 28-O-ß-D-xylopyranosyl-(1 â 4)-α-L-rhamnopyranosyl-(1 â 2)-ß-L-arabinopyranoside; 3-O-ß-D-galactopyranosyl-(1 â 2)-[α-L-arabinopyranosyl-(1 â 3)]-ß-D-glucuronopyranosyl gypsogenin 28-O-ß-D-glucopyranosyl-(1 â 3)-[ß-D-xylopyranosyl-(1 â 4)]-α-L-rhamnopyranosyl-(1 â 2)-ß-L-arabinopyranoside; 3-O-ß-D-galactopyranosyl-(1 â 2)-ß-D-glucuronopyranosyl gypsogenin 28-O-ß-D-galactopyranosyl-(1 â 3)-[ß-D-xylopyranosyl-(1 â 4)]-α-L-rhamnopyranosyl-(1 â 2)-ß-D-fucopyranoside; 3-O-α-L-rhamnopyranosyl-(1 â 3)-[ß-D-galactopyranosyl-(1 â 4)]-ß-D-glucuronopyranosyl quillaic acid 28-O-ß-D-galactopyranosyl-(1 â 3)-[ß-D-xylopyranosyl-(1 â 4)]-α-L-rhamnopyranosyl-(1 â 2)-ß-D-fucopyranoside; 3-O-α-L-rhamnopyranosyl-(1 â 3)-[ß-D-galactopyranosyl-(1 â 4)]-ß-D-glucuronopyranosyl quillaic acid 28-O-ß-D-xylopyranosyl-(1 â 3)-ß-D-xylopyranosyl-(1 â 4)-α-L-rhamnopyranosyl-(1 â 2)-ß-D-quinovopyranoside. The 50% EtOH extract showed moderate inhibitory activity on the human cancer cell line HeLa, HepG-2, MCF-7, A549, K562 and TE-1. And these six compounds were tested for cytotoxicity against K562. Among them, hylomeconoside H was found to be the most active on the K562 cell lines (IC50 6.60 µM).
Assuntos
Saponinas , Triterpenos , Saponinas/farmacologia , Triterpenos/farmacologiaRESUMO
Six undescribed oleanane-type saponins, named as Hylomeconosides L-Q, were isolated from the whole herb of Hylomecon Japonica, their structures were determined by analysis of 1D and 2D-NMR (1H-1H COSY, HSQC, and HMBC) spectroscopic data, mass spectrometry (HRESI-MS) and chromatographic data (GC and LC). Their structures were identified as 3-O-ß-D-galactopyranosyl-(1 â 2)-ß-D-glucuronopyranosyl gypsogenin 28-O-ß-D-galactopyranosyl-(1 â 3)-α-L-rhamnopyranosyl-(1 â 2)-ß-L-arabinopyranoside; 3-O-ß-D-galactopyranosyl-(1 â 2)-ß-D-glucuronopyranosyl gypsogenin 28-O-ß-D-xylopyranosyl-(1 â 4)-α-L-rhamnopyranosyl-(1 â 2)-ß-D-quinovopyranoside; 3-O-ß-D-glucuronopyranosyl gypsogenin 28-O-ß-D-xylopyranosyl-(1 â 3)-ß-D-xylopyranosyl-(1 â 4)-α-L-rhamnopyranosyl-(1 â 2)-ß-D-quinovopyranoside; 3-O-ß-D-xylopyranosyl-(1 â 3)-ß-D-glucuronopyranosyl gypsogenin 28-O-ß-D-xylopyranosyl-(1 â 4)-α-L-rhamnopyranosyl-(1 â 2)-ß-D-quinovopyranoside; 3-O-ß-D-galactopyranosyl-(1 â 2)-[α-L-rhamnopyranosyl-(1 â 3)]-ß-D-glucuronopyranosyl quillaic acid 28-O-ß-D-xylopyranosyl-(1 â 3)-ß-D-xylopyranosyl-(1 â 4)-α-L-rhamnopyranosyl-(1 â 2)-ß-D-quinovopyranoside; 3-O-ß-D-galactopyranosyl-(1 â 2)-[α-L-rhamnopyranosyl-(1 â 3)]-ß-D-glucuronopyranosyl quillaic acid 28-O-ß-D-xylopyranosyl-(1 â 3)-ß-D-xylopyranosyl-(1 â 4)-α-L-rhamnopyranosyl-(1 â 2)-ß-D-galactopyranoside. Hylomeconosides L-Q showed selective cytotoxicities against human cancer cell lines A549, AGS, HeLa, Huh 7, HT29 and K562. These results represent a contribution to the chemotaxonomy of the saponins of Hylomecon Japonica and their bioactivities.
Assuntos
Saponinas , Triterpenos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Ácido Oleanólico/análogos & derivados , Saponinas/farmacologia , Triterpenos/farmacologiaRESUMO
Three undescribed oleanane type triterpenoid saponins (1-3), along with one known saponin (4) were isolated from the whole herb of Hylomecon japonica. Their structures were elucidated by analysis of 1D and 2D-NMR (1H-1H COSY, HSQC, and HMBC) spectroscopic data, mass spectrometry (HR-ESI-MS) and chromatographic date (GC and LC) as 3-O-ß-d-glucopyranosyl-(1 â 2)-ß-d-glucuronopyranosyl gypsogenin 28-O-ß-d-galactopyranosyl-(1 â 3)-[ß-d-xylopyranosyl-(1 â 4)]-α-l-rhamnopyranosyl-(1 â 2)-ß-l-arabinopyranosyl ester (1), 3-O-ß-d-galactopyranosyl-(1 â 2)-ß-d-glucuronopyranosyl gypsogenin 28-O-α-l-arabinopyranosyl-(1 â 3)-[ß-d-xylopyranosyl-(1 â 4)]-α-l-rhamnopyranosyl-(1 â 2)-ß-l-arabinopyranosyl ester (2), 3-O-ß-d-galactopyranosyl-(1 â 2)-ß-d-glucuronopyranosyl gypsogenin 28-O-ß-d-galactopyranosyl-(1 â 3)-[ß-d-xylopyranosyl-(1 â 4)]-α-l-rhamnopyranosyl-(1 â 2)-ß-d-galactopyranosyl ester (3), 3-O-ß-d-galactopyranosyl-(1 â 2)-[α-l-arabinopyranosyl-(1 â 3)]-ß-d-glucuronopyranosyl gypsogenin 28-O-ß-d-glucopyranosyl-(1 â 3)-[ß-d-xylopyranosyl-(1 â 4)]-α-l-rhamnopyranosyl-(1 â 2)-ß-d-fucopyranosyl ester (4). All saponins possess a partial sequence ß-d-galactopyranosyl-(1 â 2)-ß-d-glucuronopyranosyl at C-3 of the aglycon. Compound 1 has cytotoxic activity against human colon cancer cell lines HT29, 3 against human gastric cancer cell lines AGS, and 4 against human lung cancer cell lines A549, AGS and HT29. Among them, compounds 3 and 4 showed significant inhibitory effect against AGS with IC50 value of 6.01 ± 1.4 µM, 3.66 ± 1.8 µM, respectively. These results represent a contribution to the chemotaxonomy of the saponins of Hylomecon japonica and their bioactivities.
Assuntos
Saponinas , Espectrometria de Massas , Raízes de Plantas/químicaRESUMO
Two dimethyltin-functionalized selenotungstates have been obtained: K4Na14[Sn(CH3)2Se6W24O94]·16H2O (1) and K8Na18[Sn(CH3)2Se6W40O145(H2O)2]Cl2·41H2O (2). They both remain cyclic selenotungstates based the on {Se2W12} units, where (CH3)2Sn2+ moieties were first introduced into "pure" POMs wheels.
RESUMO
We report an unprecedented {CuII14TeIV10} core containing the novel µ,µ-/µ6-TeIVO32- mode and TeIVO44- embedded within a 36-tungsto-4-silicate POT shell, which constitutes the first example of a tellurous copper cluster in POMs. The structure-stabilizing and templating effects of tellurite anions are crucial for this assembly. Moreover, its visible light-driven catalytic H2 evolution activity and related quenching mechanism are demonstrated, and extensive stability studies are presented.