Abstract Dodecaborate anions of the type B 12 X 2− and 11 Y (X=H, Cl, Br, I Y=OH, SH, NH 3 + , NR ) form strong (K a up to 10 6 L mol −1 for Br inclusion complexes with γ‐cyclodextrin (γ‐CD). The micromolar affinities reached are highest known this native CD. complexation exhibits highly negative enthalpies (up −25 kcal entropies (TΔS −18.4 both ), which position these guests at bottom end well‐known enthalpy‐entropy correlation CDs. high driving force can be traced back chaotropic effect,...

The energy deposition in the nucleus of cells exposed to 10B(n, alpha)7Li neutron capture reaction has been calculated and compared measured biological effect this reaction. It was found that a considerable distribution hit sizes occurs. comparison size frequency with observed survival indicates not every hit, independent its size, can lead cell death. This implies existence effectiveness function. analysis shows location boron relative radiation-sensitive volume is great importance average...

Autofluorescence of aldehyde-fixed neural tissue often complicates the use fluorescence microscopy. Background can be notably reduced or eliminated by irradiation with light before treatment probes, resulting in a higher contrast without adversely affecting staining probabilities.

The host-guest chemistry of large-ring cyclodextrins (LRCDs) has been largely unexplored due to the lack suitable guest molecules that bind with significant affinities enable potential applications. Herein, we report their complexation dodecaborate anions (B12X12(2-)), a novel class molecules. binding constants inorganic guests (10(4)-10(6) M(-1)) allow classification as first tight binders for LRCDs.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChanges in conformation of insolubilized trypsin and chymotrypsin, followed by fluorescenceDetlef Gabel, Ephraim Katchalski, Izchak Z. SteinbergCite this: Biochemistry 1971, 10, 25, 4661–4669Publication Date (Print):December 7, 1971Publication History Published online1 May 2002Published inissue 7 December 1971https://pubs.acs.org/doi/10.1021/bi00801a011https://doi.org/10.1021/bi00801a011research-articleACS PublicationsRequest reuse...

In aqueous solution, host-guest complexation is frequently driven by the hydrophobic effect, which also constitutes a popular approach in design of supramolecular assemblies. Herein, we report an orthogonal assembly motif, chaotropic exploits tendency anions to associate with surfaces.

Metallacarboranes are a class of inorganic boron clusters that have recently been recognized as biologically active compounds. Herein, we report on the host–guest complexation several cobalt bis(1,2-dicarbollide) anions (COSANs) with cyclodextrins (CDs) in aqueous solution. The binding affinities reach micromolar values, which among highest known values for native CDs, and exceed those neutral hydrophobic organic guest molecules. entrapment COSANs inside cavity CDs was confirmed using NMR...

A new type of water-soluble anchor dyes, that is, dyes which carry an auxiliary unit for strong binding to macrocyclic host molecules, has been synthesized. It consists 7-nitrobenzofurazan (NBD) as a dye and the dodecaborate cluster (B12H11R) dianionic, globular, purely inorganic anchoring group cyclodextrins (Ka > 10(5) M(-1)). The synthesized dodecaborate-substituted show marked changes in their photophysical properties (UV-vis fluorescence) upon complexation with (β-CD γ-CD), such...

Abstract Boron clusters have been employed successfully as constituents in bioactive substances. In this review, the perspectives of boron for drug design and problems to be solved a broader application are discussed, list actions is given overcoming problems.

Abstract— For a variety of chemically defined, synthetic and natural porphyrins, the tendency for self aggregation, binding to serum albumin, distribution coefficient betweenoctanol–1 water uptake in V79 Chinese hamster cells have been determined. A strong correlation was found between cell into octanol. None other factors could be correlated with uptake. These observations might an impact on use porphyrins photodynamic boron neutron capture therapy tumors.

In order to predict the efficacy of boronated compounds for neutron capture therapy (NCT), it is mandatory that boron concentration in tissues be known. Various techniques measurement trace amounts (1-100 ppm) are available, including chemical and physical procedures. Experience has shown that, with polyhedral boranes carboranes particular, usual colorimetric spark emission spectroscopic methods not reliable. Although these may traced additional radiolabels, direct detection by...

Data, from studies of covalent structure and chemical physico‐chemical behaviour 27 different homologous proteins with either neurotoxic, cardiotoxic or fytic activity isolated the venoms elapid hydrophid snakes have been collected literature. Because their small size (60–74 amino acid residues) high content disulphide bridges (4 5 bridges) these provide an unusually favourable opportunity for trials to construct models three‐dimensional indirect evidence. Such a model has built atomic...

Coupling of trypsin to cyanogen‐bromide‐activated Sephadex, but not agarose, results in a stabilization the enzyme towards denaturation by urea. Selectively N ‐acetylated derivatives were prepared and coupled Sephadex. When single amino group, which is required for immobilization reaction, was available coupling, insoluble derivative denatured as free one. The availability two or three groups coupling diminished rate considerably. more than approximately four fully active 8 M Neither binding...

Abstract Dodecaborate anions of the type B 12 X 2− and 11 Y (X=H, Cl, Br, I Y=OH, SH, NH 3 + , NR ) form strong (K a up to 10 6 L mol −1 for Br inclusion complexes with γ‐cyclodextrin (γ‐CD). The micromolar affinities reached are highest known this native CD. complexation exhibits highly negative enthalpies (up −25 kcal entropies (TΔS −18.4 both ), which position these guests at bottom end well‐known enthalpy‐entropy correlation CDs. high driving force can be traced back chaotropic effect,...

1 An extracellular proteinase from a strain of Arthrobacter was coupled to cyanogen bromide activated agarose beads. 2 The product active at fairly high temperature. No inactivation occurred upon incubation 70°, where the free enzyme rapidly inactivated. 3 leakage activity gel into solution detectable under various conditions. 4 mechanical properties and were superior untreated gel, both as regards flow rate heat stability. melting up 100°. 5 use proteolytic gels in columns allows...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis of S-alkyl and S-acyl derivatives mercaptoundecahydrododecaborate, a possible boron carrier for neutron capture therapyDetlef Gabel, Detlef Moller, Sven Harfst, Jens Roesler, Hartmut KetzCite this: Inorg. Chem. 1993, 32, 11, 2276–2278Publication Date (Print):May 1, 1993Publication History Published online1 May 2002Published inissue 1 1993https://pubs.acs.org/doi/10.1021/ic00063a014https://doi.org/10.1021/ic00063a014research-articleACS...

We have studied using molecular dynamics simulations the interaction of dodecaborate anion, B12H122–, and its amino, trimethyl, triethyl derivatives with water molecules. found peculiar organization molecules in first solvation shell formation a dihydrogen bond between hydrogen atoms anions The also show that hydration is strongly influenced by substituents anions. These differences are likely to play an important role understanding biological systems like membranes proteins aqueous environments.

The gas phase reactivity of perhalogenated closo-dodecaborate clusters [B12X12]2− (X = F, Cl, Br, I) with N-tetraalkylated ammonium counter ions was investigated by electrospray ionization ion trap mass spectrometry (ESI-IT-MS). Collisions the background gases introduced a broad variety reactions. This study represents first experimental approach to new class boron-rich boron that are not accessible in condensed phase. anionic pair [B12X12 + N(CnH2n+1)4]− is generally found as highest mass....