Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “BORATES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources
PubMed1983

Separation and analysis of 4'-epimeric UDP-sugars by borate high-performance liquid chromatography.

Separation of UDP-glucose from UDP-galactose, of UDP-N-acetylglucosamine from UDP-N-acetylgalactosamine, of UDP-glucuronate from UDP-galacturonate, or of UDP-glucosamine from UDP-galactosamine was achieved within 10-45 min by isocratic anion-exchange high-performance liquid chromatography (HPLC) using a flow rate of 2 ml/min. The eluants were composed of borate as complex-forming and eluting agent and of glycerol for protection of the alkali-labile silica packing of the column. This borate HPLC was suitable for the analysis of 4'-epimeric UDP-sugars in the range of 2 to 100 nmol. The applicability of this technique was demonstrated by determination of the relative amounts of 4'-epimeric UDP-amino sugars formed in rat liver after administration of D-galactosamine. Since a high salt content of UDP-sugar samples can interfere with borate HPLC, desalting was performed on a 1-ml C18 cartridge using triethylammonium hydrogen carbonate buffer. This procedure enabled the complete separation of various nucleotides from salts within 10 min prior to HPLC.

Animals↗
PubMed2005

The TRPV1/2/3 activator 2-aminoethoxydiphenyl borate sensitizes native nociceptive neurons to heat in wildtype but not TRPV1 deficient mice.

TRPV1 gene disruption results in a loss of capsaicin and proton responsiveness, but has minimal effects on heat-induced nocifensive behavior, suggesting that sensory transduction of heat is independent of TRPV1. TRPV3, another heat-activated ion channel but insensitive to capsaicin, was shown to be expressed in keratinocytes as well as in sensory neurons projecting to the skin. Recently, 2-aminoethoxydiphenyl borate was introduced as a TRPV3 agonist, but its selectivity was questioned by showing that it activated recombinant TRPV1 and TRPV2 as well. We used the isolated mouse skin-saphenous nerve preparation and whole-cell patch-clamping of cultured dorsal root ganglia neurons from TRPV1-/- and wildtype mice. We found no phenotypic differences between the heat responses of polymodal C-fibers, whereas cultured dorsal root ganglia neurons of TRPV1-/- hardly showed any heat-activated currents. Only C-fibers of wildtype but not TRPV1-/- mice were clearly sensitized to heat by 2-aminoethoxydiphenyl borate 10 and 100 microM; heat-activated current in wildtype neurons was only facilitated at 100 microM. Noxious heat-induced calcitonin gene-related peptide release showed clear deficits (<50%) in TRPV1 deficient skin, but the stimulated calcitonin gene-related peptide release from the isolated skull dura was unaffected. In both models, 2-aminoethoxydiphenyl borate was able to potentiate the heat response (46 degrees C, 5 min) in a concentration-dependent manner, again, only in wildtype but not TRPV1-/- mice, suggesting that TRPV2/3 are not involved in this sensitization to heat. The results further suggest that TRPV1 is not responsible for the normal heat response of native nociceptors but plays the essential role in thermal sensitization and a prominent one in controlling dermal calcitonin gene-related peptide release, i.e. neurogenic inflammation.

Animals↗
PubMed1998

High-performance liquid chromatographic analysis of polyhydroxyflavones using solid-phase borate-complex extraction.

A high-performance liquid chromatographic method using a solid-phase borate-complex extraction pretreatment was studied for the selective quantitation of polyhydroxyflavones in vegetables, red wine and human blood plasma. Homogenate, extract and intact samples were applied to phenylboric acid cartridges to retain polyhydroxyflavones on the solid-phase by forming the borate-complex, followed by elution of the retained analytes with an acidic solvent. Reversed-phase chromatography with diode array detection allowed the simultaneous separation of rutin, myricetin, fisetin, morin, quercetin and kaempferol without significant interference from other components, indicating high selectivity of the solid-phase borate-complex extraction. The absolute recoveries of quercetin, fisetin and rutin were superior to those of kaempferol, myricetin and morin, suggesting a difference in the complex formation efficiency between 1,2- and 1,3-diol structures. When using fisetin as an internal standard, polyhydroxyflavones were quantified in the concentration range 0.10-30.0 microg/ml. In replicate spiking experiments with standards, the mean relative recoveries ranged between 75.7 and 104.6%, and the intra-and inter-assay C.V.s ranged between 0.8 and 10.2% for onion, wine and plasma samples. The proposed method will be applicable to nutritional and pharmacokinetic experiments of polyhydroxyflavones.

Chromatography, High Pressure Liquid↗
PubMed2003

Homoleptic group 12 metal bis(mercaptoimidazolyl)borate complexes M(Bm(R))2 (M = Zn, Cd, Hg).

The sodium salt of the bis(2-mercapto-1-methylimidazolyl)borate anion [Bm(Me)](-) and those of the new bis(2-mercapto-1-alkylimidazolyl)borates [Bm(R)](-) (R = Bz, Bu(t), p-Tol) have been readily obtained from NaBH(4) and the appropriate 2-mercapto-1-alkylimidazoles. To contrast the binding preferences of the group 12 metals in a sulfur-rich environment, the four complete series of homoleptic complexes M[Bm(R)](2) (M = Zn, Cd, Hg), including the first bis(mercaptoimidazolyl)borate derivatives of cadmium and mercury, have been prepared. X-ray diffraction studies of Cd[Bm(Me)](2) and M[Bm(tBu)](2) (M = Zn, Cd, Hg) show the presence of distorted tetrahedral [MS(4)] central cores supplemented by two weak vicinal M.H-B bonds, interactions which appear to be a common feature in the coordination chemistry of Bm(R) ligands. In the case of zinc, it has been found that only in the presence of bulky ligands, as in Zn[Bm(tBu)](2), may an unexpected expansion in the coordination number from four to six be induced. This observation suggests the viability of octahedral intermediates in the processes whereby certain zinc enzymes transfer or exchange metal ions.

Journal Article↗
PubMed2005

Structural increments for 11-vertex nido-phospha- and aza(carba)boranes and -borates; dependence of energy penalties on the extent of Electron Localization.

Relevant structural features and corresponding energy penalties were determined that allow to easily estimate the relative stabilities of 11-vertex nido-phospha- and aza-substituted boranes, borates, carbaboranes, and carbaborates. For this purpose, density functional theory computations at the B3LYP/6-311+G(d,p)//B3LYP/6-31G(d)+ZPE level were carried out to determine the relative energies of 95 phospha- and 46 aza(carba)boranes and -borates. Energy penalties assigned to disfavoring structural features show additive behavior and excellent precision with respect to the computed results, as in the case of 6- and 11-vertex nido-carboranes and -borates. An unsubstituted phosphorus atom was found to possess energy penalties quite similar to those of the three-electron-donating H-C group. A bare nitrogen atom has energy penalties much larger than those of a bare phosphorus atom. Four-electron-donating RP and RN moieties, however, have even more adverse energy penalties. The disfavoring effects of heteroatoms in a borane cluster are determined by the amount of electron localization, that is, primarily by the number of skeletal electrons that formally originate from the heterogroup and secondarily by the electronegativity. Heteroatom energy penalties are independent of the type of the other heteroatoms present in the same cluster. Some novel phospha(carba)borane geometries with bare and exo-substituted phosphorus atoms in the same cluster have favorable thermodynamic stabilities competitive with those of known isomers.

Journal Article↗
PubMed2004

Ruthenium tris(pyrazolyl)borate diazo complexes: preparation of aryldiazenido, aryldiazene, and hydrazine derivatives.

Tris(pyrazolyl)borate aryldiazenido complexes [RuTpLL'(ArN(2))](BF(4))(2) (1-3) [Ar = C(6)H(5), 4-CH(3)C(6)H(4); Tp = hydridotris(pyrazolyl)borate; L = P(OEt)(3) or PPh(OEt)(2), L' = PPh(3); L = L' = P(OEt)(3)] were prepared by allowing dihydrogen [RuTp(eta(2)-H(2))LL'](+) derivatives to react with aryldiazonium cations. Spectroscopic characterization (IR, (15)N NMR) using the (15)N-labeled derivatives strongly supports the presence of a linear [Ru]-NN-Ar aryldiazenido group. Hydrazine complexes [RuTp(RNHNH(2))LL']BPh(4) (4-6) [R = H, CH(3), C(6)H(5), 4-NO(2)C(6)H(4); L = P(OEt)(3) or PPh(OEt)(2), L' = PPh(3); L = L' = P(OEt)(3)] were also prepared by reacting the [RuTp(eta(2)-H(2))LL'](+) cation with an excess of hydrazine. The complexes were characterized spectroscopically (IR and NMR) and by X-ray crystal structure determination of the [RuTp(CH(3)NHNH(2))[P(OEt)(3)](PPh(3))]BPh(4) (4d) derivative. Tris(pyrazolyl)borate aryldiazene complexes [RuTp(ArN=NH)LL']BPh(4) (7-9) (Ar = C(6)H(5), 4-CH(3)C(6)H(4)) were prepared following three different methods: (i). by allowing hydride species RuHTpLL' to react with aryldiazonium cations in CH(2)Cl(2); (ii). by treating aryldiazenido [RuTpLL'(ArN(2))](BF(4))(2) with LiBHEt(3) in CH(2)Cl(2); (iii). by oxidizing arylhydrazine [RuTp(ArNHNH(2))LL']BPh(4) complexes with Pb(OAc)(4) in CH(2)Cl(2) at -30 degrees C. Methyldiazene complexes [RuTp(CH(3)N=NH)LL']BPh(4) were also prepared by the oxidation of the corresponding methylhydrazine [RuTp(CH(3)NHNH(2))LL']BPh(4) with Pb(OAc)(4).

Journal Article↗
PubMed2004

Lead and thallium tetrakis(imidazolyl)borates: modifying structure by varying metal and anion.

We are using the coordinating anions tetrakis(imidazolyl)borate and tetrakis(4-methylimidazolyl)borate to construct new metal-organic framework structures. In this report, we are exploring materials similar in composition to the previously reported layered network structure Pb[B(Im)(4)](NO(3))(nH(2)O). The metal in this compound can be replaced with isoelectronic Tl(I), affording Tl[B(Im)(4)], and the borate can be modified by using 4-methylimidazole, resulting in Pb[B(4-MeIm)(4)](NO(3)) and Tl[B(4-MeIm)(4)]. Like the parent Pb[B(Im)(4)](NO(3))(nH(2)O), Tl[B(Im)(4)] and Tl[B(4-MeIm)(4)] are layered network structures but both lack anions or solvent molecules in the interlayer spacing. The material Pb[B(4-MeIm)(4)](NO(3)), however, exhibits a 3D network structure that lacks an open topology, resulting from the increased stereochemical activity (greater steric bulk toward other ligands) of the 4-methylimidazole ring. Both of the Tl(I) solids display longer M-N bonds than observed in the analogous Pb(II) compounds; these lengths account for the decreased effect of the stereochemical activity of the 4-methylimidazole ring in Tl[B(4-MeIm)(4)].

Journal Article↗
PubMed2004

Structural analysis of the conformational flexibility of tris(pyrazolyl)borate ligands and their analogues.

Database analysis and molecular mechanics were used to determine the conformational flexibility of tridentate scorpionate ligands. The tris(pyrazolyl)methane and tris(pyrazolyl)borate ligands act like molecular vises, opening their tripodal structure for larger metals and closing around smaller metal ions. Tris(3-tert-butylpyrazolyl)methane has significant preference for larger metal ions than its unsubstituted parent compound. Tris(pyrazolyl)methanes and tris(pyrazolyl)borates have similar conformational flexibilities. Placing sterically hindered groups on the central carbon or boron has only a minor effect on the geometry of the tris(pyrazolyl)methanes and tris(pyrazolyl)borates. However, it does influence the flexibility of the ligands, particularly when they have to open far from their ideal geometry, which commonly occurs.

Journal Article↗
PubMed2005

Barriers to racemization in C3-symmetric complexes containing the hydrotris(2-mercapto-1-ethylimidazolyl)borate (Tm(Et)) ligand.

The tripodal ligands hydrotris(N-ethyl-2-mercaptoimidazol-1-yl)borate (NaTm(Et)) (1) and hydrotris(N-benzyl-2-mercaptoimidazol-1-yl)borate (NaTm(Bn)) (2), analogues of the hydrotris(N-methyl-2-mercaptoimidazol-1-yl)borate ligand (Tm) containing alternative nitrogen substituents, have been employed to examine the racemization of their C3-symmetric complexes with both four- and six-coordinate metals. The ligands react at room temperature with metal halides to provide C3-symmetric metal complexes. The syntheses of the four-coordinate complexes [Tm(Et)ZnCl] (3), [Tm(Et)CdBr] (4), [Tm(Et)HgCl] (5), [Tm(Et)CuPPh3] (6), [Tm(Et)AgPPh3] (7), and [Tm(Bn)ZnCl] (8) are reported. The six-coordinate complexes [Tm(Et)Ru(p-cymene)]Cl (9), [Tm(Et)Ru(p-cymene)]PF(6) (10), and [Tm(Et)Mn(CO)3] (11) were also synthesized. The X-ray crystal structures of 3, 4, 6, and 9 are reported. The diastereotopic nature of the ethyl and benzyl hydrogen atoms in the ligands allows the enantiomeric forms of these complexes to be distinguished by 1H NMR spectroscopy. Variable-temperature (VT) 1H NMR spectra have thus been used to investigate the energies of the racemization processes occurring in these chiral complexes. In solvents the activation energies to racemization for the four-coordinate complexes lay in the range of 53-77 kJ mol(-1). In non-donor solvents the energies are reduced and a dissociative mechanism is therefore implicated. No interconversion could be observed by VT NMR for the six-coordinate complexes in any solvent. To further explore the racemization mechanisms ab initio density functional theory calculations have been conducted on the ground- and transition-state structures of representative six-coordinate [Mn(I)] and four-coordinate [Zn(II)] complexes following a proposed nondissociative mechanism of racemization. The calculated energy barriers to racemization are 163 and 121 kJ mol(-1), respectively. It is concluded that the low-energy racemization of substitution-labile four-coordinate complexes occurs via a dissociative mechanism, while substitution-inert six-coordinate complexes experience a significantly higher barrier to racemization. Whether this is due to the operation of a dissociative mechanism with a higher activation barrier or to a nondissociative mechanism remains unknown.

Journal Article↗
PubMed2006

Two new borates containing the first examples of large isolated polyborate anions: chain [B7O9(OH)5]2- and ring [B14O20(OH)6]4-.

Two novel hydrated borates were synthesized under mild solvothermal conditions. One is hydrated rubidium borate, Rb2B7O9(OH)5, which contains the first example of the isolated chain heptaborate anion, [B7O9(OH)5]2-. The other is hydrated diethylenetriamine borate, [(C4H15N3)]2[B14O20(OH)6], which contains the first example of the largest isolated ring tetradecaborate anion, [B14O20(OH)6]4-.

Journal Article↗
PubMed1996

Synthesis and Characterization of Copper(II), Zinc(II), and Potassium Complexes of a Highly Fluorinated Bis(pyrazolyl)borate Ligand.

Highly fluorinated, dihydridobis(3,5-bis(trifluoromethyl)pyrazolyl)borate ligand, [H(2)B(3,5-(CF(3))(2)Pz)(2)](-) has been synthesized and characterized as its potassium salt. The copper(II) and zinc(II) complexes, [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Cu and [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Zn, have been prepared by metathesis of [H(2)B(3,5-(CF(3))(2)Pz)(2)]K with Cu(OTf)(2) and Zn(OTf)(2), respectively. All the new metal adducts have been characterized by X-ray diffraction. The potassium salt is polymeric and shows several K.F interactions. The Cu center of [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Cu adopts a square planar geometry, whereas the Zn atom in [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Zn displays a tetrahedral coordination. Bis(pyrazolyl)borate ligands in the Zn adduct show a significantly distorted boat conformation. The nature and extent of this distortion is similar to that observed for the methylated analog, [H(2)B(3,5-(CH(3))(2)Pz)(2)](2)Zn. This ligand allows a comparison of electronic effects of bis(pyrazolyl)borate ligands with similar steric properties. Crystallographic data for [H(2)B(3,5-(CF(3))(2)Pz)(2)]K: triclinic, space group P&onemacr;, with a = 8.385(1) Å, b = 10.097(2) Å, c = 10.317(1) Å, alpha = 104.193(9) degrees, beta = 104.366(6) degrees, gamma = 91.733(9) degrees, V = 816.5(3) Å(3), and Z = 2. [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Cu is monoclinic, space group C2/c with a = 25.632(3) Å, b = 9.197(1) Å, c = 17.342(2) Å, beta = 129.292(5) degrees, V = 3164.0(6) Å(3), and Z = 4. [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Zn is triclinic, space group P&onemacr;, with a = 9.104(1) Å, b = 9.278(1) Å, c = 18.700(2) Å, alpha = 83.560(6) degrees, beta = 88.200(10) degrees, gamma = 78.637(9) degrees, V = 1538.8(3) Å(3), and Z = 2. [H(2)B(3,5-(CH(3))(2)Pz)(2)](2)Zn is monoclinic, space group C2/c with a = 8.445(1) Å, b = 14.514(2) Å, c = 19.983(3) Å, beta = 90.831(8) degrees, V = 2449.1(6) Å(3), and Z = 4.

Journal Article↗
PubMed1998

Halocarbonyltungsten(II) Complexes Containing Tripodal Tris(pyrazolyl)borate Ligands.

The halo tricarbonyl complexes LWX(CO)(3) (X = I, Br, Cl) are formed when NEt(4)[LW(CO)(3)] is reacted with I(2), N-bromosuccinimide, and N-chlorosuccinimide (or PhICl(2)), respectively, while reaction of NEt(4)[L(Pr)W(CO)(3)] and I(2) yields L(Pr)WI(CO)(3) [L = hydrotris(3,5-dimethylpyrazol-1-yl)borate, L(Pr) = hydrotris(3-isopropylpyrazol-1-yl)borate]. Reaction of NEt(4)[LW(CO)(3)] with Br(2) yields mixtures of LWBr(CO)(3) and L(Br)WBr(CO)(3) [L(Br) = hydrotris(4-bromo-3,5-dimethylpyrazol-1-yl)borate] as a result of competitive bromination of both tungsten and ligand L. The complexes generally exhibit three nu(CO) bands, one at ca. 2025 cm(-)(1) and two between 1930 and 1900 cm(-)(1), and NMR spectra consistent with fluxional carbonyl-capped octahedral (C(s)()) structures. Crystals of L(Pr)WI(CO)(3).MeOH are orthorhombic, space group Pbca, with a = 11.779(2) Å, b = 15.975(4) Å, c = 29.476(3) Å, and V = 5547(2) Å(3) for Z = 8. The seven-coordinate complex exhibits a 3:3:1 carbonyl-capped octahedral structure. In hot acetonitrile or tetrahydrofuran, the tricarbonyl complexes are converted into brown, paramagnetic (&mgr;(eff) ca. 1.15 &mgr;(B)) dicarbonyl species, LWX(CO)(2) and L(Br)WBr(CO)(2), which exhibit two nu(CO) bands (ca. 1930 and 1840 cm(-)(1)) and isotropically shifted NMR spectra consistent with a mononuclear structure with C(s)() symmetry. Further decarbonylation of L(Br)WBr(CO)(2) in refluxing acetonitrile results in the formation of L(Br)WBr(MeCN-kappa(2)N,C)(CO), which crystallizes in monoclinic space group C2/c, with a = 22.245(4) Å, b = 19.077(4) Å, c = 15.639(3) Å, beta = 128.61(2) degrees, and V = 5286(2) Å(3) for Z = 8. The seven-coordinate complex features a "side-on" bonded, four-electron-donor acetonitrile ligand and a completely 4-brominated L(Br) ligand.

Journal Article↗
PubMed2001

Simple, tunable aziridination catalysts based on poly(pyrazolyl)borate-copper complexes.

[reaction: see text] The in situ generation of a copper-poly(pyrazolyl)borate complex from copper chloride and a sodium poly(pyrazolyl)borate salt results in a catalyst that is effective for the aziridination of olefins. A significant influence of the combination of the starting copper oxidation state and the hapticity of the poly(pyrazolyl)borate ligand on the efficiency of the reaction has been observed.

Journal Article↗
PubMed2004

Manganese(I) poly(mercaptoimidazolyl)borate complexes: spectroscopic and structural characterization of Mn...H-B interactions in solution and in the solid state.

The manganese(I) tricarbonyl complexes (Bm(R))Mn(CO)3(R = Me, Bz, But, p-Tol) and (PhBmMe)Mn(CO)3, the first bis(mercaptoimidazolyl)borate derivatives for this metal, have been readily prepared and fully characterized. In particular, the presence of three-center-two-electron Mn...H-B interactions in these species, both in solution and in the solid state, has been investigated using a combination of IR and NMR spectroscopies and, in the case of the methyl-, tert-butyl- and para-tolyl-substituted derivatives, by X-ray crystallography. To complement these synthetic and structural studies, the tris(mercaptoimidazolyl)borate complexes (TmMe)Mn(CO)3(R = Me, Bz, But, p-Tol) and (PhTm(Me))Mn(CO)3, as well as the related pyrazolylbis(mercaptoimidazolyl)borate (pzBmMe)Mn(CO)3, have also been synthesized and characterized by a combination of analytical and spectroscopic techniques.

Journal Article↗
PubMed1976

The use of sodium borate impregnated silica gel plates for the separation of 3-0-methyl catecholamines from their corresponding catecholamines.

The use of sodium borate impregnated silica gel plates for the chromatographic separation of the catecholamines noradrenaline, adrenaline, and isoprenaline from their respective 3-0-methylated derivatives, normetanephrine, metanephrine, and methoxy-isoprenaline, is described. The parent catecholamines remain at the origin of the plates while the 3-0-methylated derivatives concentrate in discrete bands at the upper edge of the borate impregnated area (the "borate front").

Catecholamines↗
PubMed1970

Effect of borate on the growth of coagulase-positive and coagulase-negative staphylococci.

Of 235 strains of coagulase-positive Staphylococcus aureus studied, 221 or 94% were inhibited by 1.5 x 10(-8)m sodium borate, whereas only 6 of 57 (10.5%) coagulase-negative strains were inhibited by the same borate concentration. Four of the six coagulase-negatives were food poisoning strains and one was a hospital pathogen. Borate sensitivity was found to correlate well with lysozyme and alpha-toxin production by coagulase-positive strains.

Journal Article↗
PubMed1971

Four-directional-development thin-layer chromatography of lipids using trimethyl borate.

Solvent mixtures containing trimethyl borate virtually eliminated the pronounced interconversion of 1,2- and 1,3-dipalmitins during their resolution by thin-layer chromatography on Silica Gel G. With trimethyl borate, an average of 1-2% of 1,2-dipalmitin was converted to 1,3-dipalmitin. A four-directional-development TLC procedure incorporating trimethyl borate resolves cholesteryl glucoside, ceramides, monogalactosyl diglyceride, 1- and 2-monopalmitin, palmitic acid, cholesterol, 1,2- and 1,3-dipalmitin, tripalmitin, methyl palmitate, cholesteryl palmitate, beta-carotene and some of its degradation products, squalene, and tetracosane. Digalactosyl diglyceride, phosphatidic acid, phosphatidylglucose, cerebrosides, and other phospholipids remain near the origin. A mixture containing triolein, 1,2- and 1,3-diolein, 1- and 2- monoolein, oleic acid, and cholesterol was resolved in one dimension. A similar series of palmitic-containing neutral lipids was also resolvable in one dimension. These procedures were applied to the TLC of human sera lipids.

Acetates↗
PubMed2005

Chiral ligand exchange micellar electrokinetic chromatography using borate anion as a central ion.

Three compounds having 1,2-diol structure (1-phenyl-1,2-ethanediol, 3-phenoxy-1,2-propanediol, and 3-benzyloxy-1,2-propanediol) were enantioseparated by ligand exchange MEKC using (5S)-pinanediol (SPD) as a chiral selector and borate anion as a central ion together with SDS. When (S)-1,2-propanediol, (S)-1,2,4-butanetriol, or (S)-3-tert-butylamino-1,2-propanediol were used as the chiral ligand instead of SPD, these three compounds were not enantioseparated. When borate was replaced with 2-aminoethane-1-sulfonate or N-cyclohexyl-3-aminopropanesulfonate, no chiral separation was achieved. Therefore, the hydrophobic interaction between the chiral selector and the chiral analytes within the transient diastereomeric complex may play an important role in the enantioseparation achieved by the proposed method.

Borates↗