Digoxin and its Na/K-ATPase-targeted actions on cardiovascular diseases and cancer.

Na/K-ATPase (NKA) is a plasma membrane ion-transporting protein involved in the generation and maintenance of Na and K gradients across the cell membrane, which can produce a driving force for the secondary transport of metabolic substrates. NKA also regulates intracellular calcium that is responsible for modulating numerous cellular processes, while it interacts with many other proteins and functions as a signal transducer, with several signaling pathways being involved. Thus, NKA has become an important target for the treatment of human diseases.

Development of Potential Therapeutic Agents from Black Elderberries (the Fruits of L.).

Elderberry ( L.) is a widespread deciduous shrub, of which the fruits (elderberries) are used in the food industry to produce different types of dietary supplement products. These berries have been found to show multiple bioactivities, including antidiabetic, anti-infective, antineoplastic, anti-obesity, and antioxidant activities.

Vincamine, from an antioxidant and a cerebral vasodilator to its anticancer potential.

Vincamine is a naturally occurring indole alkaloid showing antioxidant activity and has been used clinically for the prevention and treatment of cerebrovascular disorders and insufficiencies. It has been well documented that antioxidants may contribute to cancer treatment, and thus, vincamine has been investigated recently for its potential antitumor activity. Vincamine was found to show cancer cell cytotoxicity and to modulate several important proteins involved in tumor growth, including acetylcholinesterase (AChE), mitogen-activated protein kinase (MAPK), nuclear factor-κB (NF-κB), nuclear factor erythroid 2-related factor 2 (Nrf2), and T-box 3 (TBX3).

Panchromatic dirhodium photocatalysts for dihydrogen generation with red light.

A series of three dirhodium complexes -[Rh(DPhB)(bncn)](BF) (, DPhB = diphenylbenzamidine; bncn = benzocinnoline), -[Rh(DPhTA)(bncn)](BF) (, DPhTA = diphenyltriazenide), and -[Rh(DPhF)(bncn)](BF) (, DPhF = ,'-diphenylformamidinate) shown to act as single-molecule photocatalysts for H production was evaluated. Complexes are able to generate H in the absence of any other catalyst in homogenous acidic solution upon irradiation with red light in the presence of the sacrificial electron donor BNAH (1-benzyl-1,4-dihydronicotinamide). The excited state of each complex is reductively quenched by BNAH, producing the corresponding one-electron reduced complex.

α-Pyrone and Sterol Constituents of , a Fungal Associate of the Lichen .

Four new metabolites, 4--citreoviridin (), auransterol (), and two analogues ( and ) of paxisterol (), together with two known metabolites (15*,20*)-dihydroxyepisterol () and (), were isolated from cultures of the fungal associate, , of the lichen , endemic to California and Baja California. The structures of all compounds were determined by comprehensive spectroscopic and spectrometric methods, as well as single-crystal X-ray diffraction for the determination of the absolute configuration of . Compound showed selective cytotoxicity toward MCF-7 breast and A2780 ovarian cells with IC values of 4.

Cationic Co(I)-Intermediates for Hydrofunctionalization Reactions: Regio- and Enantioselective Cobalt-Catalyzed 1,2-Hydroboration of 1,3-Dienes.

Much of the recent work on catalytic hydroboration of alkenes has focused on simple alkenes and styrene derivatives with few examples of reactions of 1,3-dienes, which have been reported to undergo mostly 1,4-additions to give allylic boronates. We find that reduced cobalt catalysts generated from 1,n- bis-diphenylphosphinoalkane complexes [PhP-(CH) -PPh]CoX; n = 1-5) or from (2-oxazolinyl)phenyldiarylphosphine complexes [(G-PHOX)CoX] (G = 4-substituent on oxazoline ring) effect selective 1,2-, 1,4-, or 4,3-additions of pinacolborane (HBPin) to a variety of 1,3-dienes depending on the ligands chosen. Conditions have been found to optimize the 1,2-additions.

Crystal Structures and Human Leukemia Cell Apoptosis Inducible Activities of Parthenolide Analogues Isolated from Piptocoma rufescens.

The molecular structures of three parthenolide analogues, (-)-goyazensolide (1), (-)-15-deoxygoyazensolide (2), and (-)-ereglomerulide (3), isolated from the leaves of Piptocoma rufescens in a previous study were determined by X-ray analysis, and the absolute configuration of (-)-goyazensolide (1) was confirmed crystallographically using Cu Kα radiation at low temperature. Compounds 1-3, (+)-rufesolide A (4), and commercial parthenolide were found to be growth inhibitory toward MOLM-13 and EOL-1 human acute myeloid leukemia cells using PKC412 (midostaurin) as the positive control, with 1-3 being more active than parthenolide. Also, compounds 1-4 exhibited synergistic effects when tested with PKC412, but parthenolide did not show this type of activity.

Catalytic Enantioselective Hetero-dimerization of Acrylates and 1,3-Dienes.

1,3-Dienes are ubiquitous and easily synthesized starting materials for organic synthesis, and alkyl acrylates are among the most abundant and cheapest feedstock carbon sources. A practical, highly enantioselective union of these two readily available precursors giving valuable, enantio-pure skipped 1,4-diene esters (with two configurationally defined double bonds) is reported. The process uses commercially available cobalt salts and chiral ligands.

New Rh(II,II) Complexes for Solar Energy Applications: Panchromatic Absorption and Excited-State Reactivity.

The new heteroleptic paddlewheel complexes cis-[Rh(μ-form)(μ-np)][BF], where form = p-ditolylformamidinate (DTolF) or p-difluorobenzylformamidinate (F-form) and np = 1,8-napthyridyine, and cis-Rh(μ-form)(μ-npCOO) (npCOO = 1,8-naphthyridine-2-carboxylate), were synthesized and characterized. The complexes absorb strongly throughout the ultraviolet (λ = 300 nm, ε = 20 300 M cm) and visible regions (λ = 640 nm ε = 3500 M cm), making them potentially useful new dyes with panchromatic light absorption for solar energy conversion applications. Ultrafast and nanosecond transient absorption and time-resolved infrared spectroscopies were used to characterize the identity and dynamics of the excited states, where singlet and triplet Rh/form-to-naphthyridine, metal/ligand-to-ligand charge-transfer (ML-LCT) excited states were observed in all four complexes.

Probing Interligand Electron Transfer in the MLCT S Excited State of trans-MoLL' Compounds: A Comparative Study of Auxiliary Ligands and Solvents.

The interligand charge dynamics of the lowest singlet metal-to-ligand charge-transfer states (MLCT S states) of a series of quadruply bonded trans-Mo(NN)(OC-X) paddlewheel compounds are investigated, where NN is a π-accepting phenylpropiolamidinate ligand and OC-X (X = Me, Bu, TPB, or CF) is an auxiliary carboxylate ligand. The compounds show strong light absorption in the visible region due to MLCT transitions from the Mo center to the NN ligands. The transferred electron density was followed by femtosecond time-resolved infrared (fs-TRIR) spectroscopy with vibrational reporters such as the ethynyl groups on the NN ligands.

An Intramolecular CAr-H•••O=C Hydrogen Bond and the Configuration of Rotenoids.

Over the past half a century, the structure and configuration of the rotenoids, a group of natural products showing multiple promising bioactivities, have been established by interpretation of their NMR and electronic circular dichroism spectra and confirmed by analysis of single-crystal X-ray diffraction data. The chemical shift of the H-6' H NMR resonance has been found to be an indicator of either a or C/D ring system. In the present study, four structures representing the central rings of a -, a -, a dehydro-, and an oxadehydro-rotenoid have been plotted using the program based on X-ray crystal structures reported previously, with the conformations of the C/D ring system, the local bond lengths or interatomic distances, hydrogen bond angles, and the H-6' chemical shift of these compounds presented.

Femtosecond Study of Dimolybdenum Paddlewheel Compounds with Amide/Thioamide Ligands: Symmetry, Electronic Structure, and Charge Distribution in the MLCT S State.

Four photophysically interesting dimolybdenum paddlewheel compounds are synthesized and characterized: I and II contain amide ligand (N,3-diphenyl-2-propynamide), and III and IV contain thioamide ligand (N,3-diphenyl-2-propynethioamide). I and III are trans-MoL(OC-TPB)-type compounds, and II and IV are MoL-type compounds, where OC-TPB is 2,4,6-triisopropylbenzoate. I-IV display strong light absorption due to metal to ligand charge transfer (MLCT) transitions from molybdenum to the amide/thioamide ligands.

Potent cytotoxic arylnaphthalene lignan lactones from Phyllanthus poilanei.

Two new (1 and 2) and four known arylnaphthalene lignan lactones (3-6) were isolated from different plant parts of Phyllanthus poilanei collected in Vietnam, with two further known analogues (7 and 8) being prepared from phyllanthusmin C (4). The structures of the new compounds were determined by interpretation of their spectroscopic data and by chemical methods, and the structure of phyllanthusmin D (1) was confirmed by single-crystal X-ray diffraction analysis. Several of these arylnaphthalene lignan lactones were cytotoxic toward HT-29 human colon cancer cells, with compounds 1 and 7-O-[(2,3,4-tri-O-acetyl)-α-L-arabinopyranosyl)]diphyllin (7) found to be the most potent, exhibiting IC50 values of 170 and 110 nM, respectively.

4-Nitrophenyl- and 4'-nitro-1,1'-biphenyl-4-carboxylates attached to Mo2 quadruple bonds: ground versus excited state M2δ-ligand conjugation.

From the reactions between Mo2(T(i)PB)4, where T(i)PB = 2,4,6-triisopropylbenzoate and two equivalents of the carboxylic acid LH (LH = 4-nitrobenzoic acid and 4'-nitro[1,1'-biphenyl]-4-carboxylic acid) the compounds trans-M2(T(i)PB)2L2 have been prepared: I (L = 4-nitrobenzoate and M = Mo), II (L = 4'-nitro-1,1'-biphenylcarboxylate and M = Mo) and III (L = 4-nitrobenzoate and M2 = MoW). The compounds have been characterized by (1)H NMR, UV-Vis and steady state emission spectroscopy, ns and fs transient absorption spectroscopy and cyclic voltammetry. These data are compared with predictions based on electronic structure calculations on model compounds where T(i)PB is substituted for formate.

Desolvation and dehydrogenation of solvated magnesium salts of dodecahydrododecaborate: relationship between structure and thermal decomposition.

Attempts to synthesize solvent-free MgB12H12 by heating various solvated forms (H2O, NH3, and CH3OH) of the salt failed because of the competition between desolvation and dehydrogenation. This competition has been studied by thermogravimetric analysis (TGA) and temperature-programmed desorption (TPD). Products were characterized by IR, solution- and solid-state NMR spectroscopy, elemental analysis, and single-crystal or powder X-ray diffraction analysis.

N-[2-(9H-Carbazol-9-yl)eth-yl]-4-(methyl-sulfon-yl)aniline.

In the title mol-ecule, C21H20N2O2S, the dihedral angle between the mean plane of the carbazole ring system [maximum deviation = 0.021 (4) Å] and the benzene ring is 80.15 (6)°.

(E)-3-(9-Ethyl-9H-carbazol-3-yl)-1-(2-meth-oxy-phen-yl)prop-2-en-1-one.

In the title mol-ecule, C24H21NO2, the dihedral angle between the carbazole ring system [with a maximum deviation of 0.052 (2) Å] and the benzene ring is 38.6 (1)°.

Photoinduced intercalation and coordination of a dirhodium complex to DNA: dual DNA binding.

Two new complexes, cis-H,H-[Rh2 (OCCH3 NH)2 (LL)(CH3 CN)2 ](2+) , where LL=bpy (2, bpy=2,2'-bipyridine) and dppz (3, dppz=dipyrido[3,2-a:2',3'-c]phenazine), were prepared from the reaction of cis-H,H-[Rh2 (OCCH3 NH)2 (CH3 CN)6 ](2+) (1) with the corresponding bidentate ligand. The bpy and dppz ligands chelate to the same rhodium atom and are positioned trans to the amidato N atoms, as determined by the single crystal X-ray structure of 2. Irradiation of 2 and 3 with visible light in water results in the exchange of one CH3 CNeq ligand for an H2 O molecule with quantum yields, Φ400 , of 0.

Caeruleanone A, a rotenoid with a new arrangement of the D-ring from the fruits of Millettia caerulea.

Caeruleanone A (1), a novel rotenoid with an unprecedented arrangement of the D-ring, was isolated with another two new analogues, caeruleanones B (2) and C (3), together with 11 known rotenoids from the fruits of Millettia caerulea. The structures of the new compounds were determined by spectroscopic data analysis, with that of 1 being confirmed by single-crystal X-ray diffraction. Compounds 2 and 3 displayed potent mitochondrial transmembrane potential inhibitory and quinone reductase induction activities.

THF exchange and molecular dynamics in the series (BDI)MgX(THF), where X = Bu(n), NEt2, and OBu(t) and BDI = 2-[(2,6-diisopropylphenyl)amino]-4-[(2,6-diisopropylphenyl)imino]pent-2-ene.

The complexes (BDI)MgX(THF), where X = Bu(n), NEt2, and OBu(t), are shown to undergo THF exchange at low added concentrations of THF by a dissociative mechanism: X = Bu(n), ΔH(#) (kcal mol(-1)) = 13.4 ± 0.4 and ΔS(#) (cal mol(-1) K(-1)) = 6.

Single-site bismuth alkoxide catalysts for the ring-opening polymerization of lactide.

Salen bismuth alkoxides, where the salen ligand contains 2,4-di-tert-butylphenoxy groups and one of ethylene, cyclohexane or ortho-phenyl as a backbone have been prepared from reactions involving Bi[N(SiMe₃)₂]₃ and the free salen ligand followed by alcoholysis (ButOH, PriOH and 2,6-But₂C₆H₃OH). The molecular structures of the salen ligand with the cyclohexyl back-bone have been determined for the complexes salenBiCl and salenBiOC₆H₃-2,6-But₂. The chloro compound is a dimer with chloride bridges while the phenoxide is monomeric with an unusually distorted five-coordinate geometry.

Photoinduced ligand exchange and DNA binding of cis-[Ru(phpy)(phen)(CH3CN)2]+ with long wavelength visible light.

The complex cis-[Ru(phpy)(phen)(CH3CN)2](+) (phpy=2-phenylpyridine, phen=1,10-phenanthroline) was investigated as a potential photodynamic therapy (PDT) agent. This complex presents desirable photochemical characteristics including a low energy absorption tail extending into the PDT window (600-850nm) and photoinduced exchange of the CH3CN ligands, generating a species analogous to the chemotherapy drug cisplatin. Furthermore, photochemical reactivity can be controlled through selective irradiation into the Ru-phen singlet metal-to-ligand charge transfer ((1)MLCT) band (λirr=500 nm) of [Ru(phpy)(phen)(CH3CN)2](+) in the presence of excess t-butylammonium chloride (TBACl) resulting in efficient photoinduced production of [Ru(phpy)(phen)(CH3CN)Cl] (Φ=0.

New syntheses and structural characterization of NH3BH2Cl and (BH2NH2)3 and thermal decomposition behavior of NH3BH2Cl.

New convenient procedures for the preparation of ammonia monochloroborane (NH(3)BH(2)Cl) and cyclotriborazane [(BH(2)NH(2))(3)] are described. Crystal structures have been determined by single-crystal X-ray diffraction. Strong H···Cl···H bifurcated hydrogen bonding and weak N-H···H dihydrogen bonding are observed in the crystal structure of ammonia monochloroborane.

Photoinduced ligand exchange and covalent DNA binding by two new dirhodium bis-amidato complexes.

Two new dirhodium complexes, the head-to-tail (H,T) and head-to-head (H,H) isomers of cis-[Rh(2)(HNOCCH(3))(2)(CH(3)CN)(6)](2+), were synthesized, separated, and characterized following the reaction of Rh(2)(HNOCCH(3))(4) with trimethyloxonium tetrafluoroborate in CH(3)CN. The products were characterized by (1)H NMR spectroscopy, mass spectrometry, elemental analysis, and single crystal X-ray diffraction. Each bis-amidato isomer has a total of six CH(3)CN ligands, two along the internuclear Rh-Rh axis, CH(3)CN(ax), two in equatorial positions trans to the oxygen atoms of the bridging amidato groups, CH(3)CN(eq)(O), and two in equatorial positions trans to the amidato nitrogen atoms, CH(3)CN(eq)(N).

Molecular and electronic structures and photophysical properties of quadruply bonded dimetal complexes (M = Mo or W) supported by trans-arylethynylcarboxylate ligands where aryl = p-tolyl or 9-anthrancenyl.

From the reactions between M(2)(T(i)PB)(4), where T(i)PB = 2,4,6-triisopropylbenzoate and M = Mo or W, in toluene and each of the respective carboxylic acids (2 equiv) the quadruply MM bonded compounds trans-M(2)(T(i)PB)(2)(O(2)C-C≡C-Ar)(2) have been prepared where Ar = p-tolyl and M = Mo, , and M = W, , and Ar = 9-anthracenyl, where M = Mo, 2a, and M = W, 2b. Single crystal X-ray crystallographic studies of 1a and 2b confirmed the trans substitution pattern about the Mo(2)(4+) unit and the centrosymmetric molecules have structural features that indicate extensive Lπ-Mo(2)δ-Lπ conjugation involving the arylethynylcarboxylates. The compounds are intensely colored as a result of the HOMO → LUMO, metal δ-to-ligand π* charge transfer (1)MLCT transition: 1a (orange), 1b (red), 2a (blue) and 2b(green).