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Zusammenfassung Einige organische Borverbindungen werden im Vergleich zu Borsaure auf ihre fungistatische, fungizide und trichomonastatische Qualitat gepruft. Den besten MHK-Wert gegenuber Dermatophyten mit ca. 5 ppm Borgehalt zeigte Diphenylborsaure-2-aminoathylester. Gegenuber Trichomonas vaginalis wirkte Natrium-tetraphenylborat am besten (MHK 1,6 ppm Borgehalt). Fungizide Qualitaten konnten bei der Borsaure nicht entdeckt werden, wahrend Phenylborsaure in 1 %iger Losung Mikrosporon gypseum und Trichophyton mentagrophytes in 5 Stunden totet. Ein Zusatz von Sorbit zu Borsaurelosungen zwecks Steigerung der Loslichkeit fuhrt zum Verlust der schon schwachen Wirkung der Borsaure. Die unterschiedlichen MHK-Werte der Borsaure gegenuber verschiedenen Dermatophyten werden aufgezeigt. Summary The fungistatic, fungicidal and trichomonastatic properties of some organoboron compounds have been tested in comparison to boric acid. The best MIC-value against dermatophytes (5 ppm boron content) was shown by 2-aminoethyl diphenylborate. Sodium tetraphenylborate with a MIC-value of 1.6 ppm boron content was the most effective against Trichomonas vaginalis. Whereas boric acid showed no fungicidal properties, a 1 % solution of phenyl boric acid killed Mikrosporon gypseum and Trichophyton mentagrophytes in 5 hours. The addition of sorbit to the boric acid solutions in order to increase the solubility lead to a loss of the already weak effect of the boric acid. The differing MIC-values of boric acid against dermatophytes are reported.

New boron derivatives of dithiophosphonic acids 3a–c and 5 were obtained in the reactions of Lawesson's reagent 1a and its homologue 1b with trialkyl borates 2a–c and O-isobutyl diphenylborate 4. Low frequency ultrasound irradiation (22 kHz, power 130 W) leads to reduction in reaction temperature and time in the reactions studied. The prepared compounds were identified by IR, 1H, and 31P NMR and mass spectra as well as elemental analyses.

The reactions of tetraphosphorus decasulfide 1 with trialkyl borates 2a,b and O-isobutyl diphenylborate 2c were studied. On the basis of these studies, a novel method of synthesizing S-boron derivatives of dithiophosphoric acids was developed. The use of low frequency ultrasonic irradiation (22 kHz, power 130 W) leads to a reduction in reaction temperature and time required for completion of the reactions studied. © 2000 John Wiley & Sons, Inc. Heteroatom Chem 11:102–106, 2000

The reactions of isobutyl diphenylborate with 0,0-diethyl o-hydroxyphenylphosphonate and o-hydroxyphenylphosphine gave 5,6-benzo-2-phenyl-4-ethoxy-4-oxo 1,3,2,4-dioxaboraphosphorinane and o-diphenylboryloxyphenylphosphine, respectively. The borylation only at theα-hydroxyalkyl fragments of bis(β,β,β-trichloro-α-hydroxyethyl)(o-hydroxyphenyl)phosphine and the conversion of the o-boryloxyphenyl phosphorus derivative to anα-boryloxyalkyl derivative upon the action of chloral indicates the greater stability of compounds with the P-C-O-B fragment than that for compounds with the P-C-C-O-B fragment.

A DFT study of the geometrical, electronic, and energetic parameters of homo- and heterochiral complexes of fluoro derivatives of diphenylborate and isoelectronic structures where the central atom has been substituted by carbon and nitrogen has been carried out. The results have allowed correlation of the relative energies (hetero- minus homochiral complex) versus the presence of fluorine in the different positions on the aromatic rings and the presence of different central atoms. Other correlations between geometrical parameters and the relative energy have also been found. Some of the predictions have been confirmed with the calculation of new derivatives. © 2005 Elsevier Ltd. All rights reserved.

Calcium entry is a component of the processes regulating the proliferative phenotype of some types of cancer. In non-excitable cells, capacitative calcium entry (CCE) and non-capacitative calcium entry (NCCE) are thought to be the main pathways of Ca 2+ influx into cells. Thus, blocking calcium entry may prevent normal and pathological cell proliferation and there is evidence to suggest that molecules blocking calcium entry also have antiproliferative properties. Carboxyamidotriazole (CAI), a novel inhibitor of the non-voltage-dependent calcium entry has been shown to have such properties in model systems in vitro and in vivo. We used Hep G2 and Huh-7 human hepatoma cells to investigate the effects of calcium entry blockers on cell proliferation. CAI (10 μM) and 2-APB (20 μM) completely blocked CCE in thapsigargin-treated Huh-7, and CAI and 2-APB inhibited cell proliferation with IC 50 of 4.5 and 43 μM, respectively. The plateau phase of the [Ca 2+ ] i increases triggered by 10% FCS were abolished in the absence of external Ca 2+ and in the presence of CAI or 2-APB. We, therefore, suggest that CCE is the main pathway involved in regulation of the processes leading to cell proliferation.

Cycloaddition of CH3CN to a Ph2B(pz) fragment was discovered during explorations of the reactions of the new ligands Ph2B(pzR,R‘)2- (pz = 3,5-R,R‘-pyrazolyl; R = Ph, R‘ = H and R and R‘ = CH3) with [Cu(CH3CN)4]SbF6. Thus, while treatment of Na[Ph2B(pzPh,H)2] with [Cu(CH3CN)4]SbF6 afforded [Ph2B(pzPh,H)2]Cu(HpzPh,H) that exhibited the expected bidentate coordination of the bis(pyrazolyl)borate ligand in its X-ray crystal structure, the analogous reaction with Na[Ph2B(pzCH3CH3)2] led to the product shown in the figure.

A prepurification procedure for the determination of catecholamines in biological samples was studied to simplify the procedure and increase selectivity and recovery. The procedure is based on liquid/liquid extraction of catecholamine-borate complexes. Under optimal conditions, catecholamines formed complexes with diphenylborate in an alkaline NH 4 Cl/NH 4 OH buffer that were extracted with n-heptanol. Catecholamines were reextracted into an HCl-acidified solution, followed by reversed-phase ion-pair high-performance liquid Chromatographic separation with fluorometric detection. Application of the method to various samples of rat tissues and human urine showed procedural simplicity, high selectivity, and high recovery (about 90% or more for tissue samples). This method can be used for pharmacological studies on catecholamines.

Electrochemical detection of eluted solutes in HPLC is now well established as a selective and highly sensitive technique. Measurement of catecholamines and metabolites has been the most popular application with an exponential increase in literature. Recent improvements include the use of diphenylborate for extractions, the introduction of smaller diameter HPLC materials which improve resolution and sensitivity, and the replacement of carbon paste with glassy carbon which now gives a more stable electrode with similar sensitivity. Applications of HPLC with amperometric detection to the determination of drugs, amino acids and peptides are discussed.

1. In the reaction of phenylphosphine with aldehydes and isobutyl diphenylborate, 2,2,5-triphenyl-4,6-di-R-5-a-hydrozyalkyl-1,3,2,5-dioxaborataphosphoniarinanes were obtained. 2. The reaction of 2,2,5-triphenyl-4,6-di-R-l,3,2,5-dioxaborataphosphoniarinanes with aliphatic aldehydes leads to a displacement of aldehydic fragments with retention of the structure of the molecule. 3. In the reaction of 2,2,5-triphenyl-4,6-di-R-l,3,2,5-dioxaborataphosphoniarinane and ammonium 1,3,2,5-dioxaborataphosphorinanes with nitriles, only one aldehyde fragment is displaced, and diphenylboryloxyalkyl (imidoyl)phenylphosphines are formed.

Hydroxymethyldiphenylboryloxymethylphenylphosphine and 2,5-diphenyl-2-bora-1,3,5-di-oxaphosphorinane, in which the phenyl group at the phosphorus atom is predominantly found in the axial position, are formed in the reaction of di(hydroxymethyl)phenylphosphine with isobutyl diphenylborate.

1. The reaction of methyl(hydroxymethyl)phenylphosphine with isobutyl diphenylborate yields 2,2,5-tri-phenyl-5-methyl-2-boronata-5-phosphonia-1,3-dioxane, which upon distillation, liberates formaldehyde and gives diphenylboryloxymethyl(methyl)phenylphosphine containing an active P-C-O-B system. 2. The reaction of diethylaminomethyl(methyl)phenylphosphine with isobutyl diphenylborate proceeds with intermediate hydride transfer.

The reaction of bis(hydroxymethyl)phenylphosphine oxide with isobutyl diphenylborate catalyzed by secondary and tertiary amines as well as by ammonia leads to ammonium 2,2,5-triphenyl-5-oxo-1, 3,2,5-dioxaborataphosphorinanes.

1. The reaction of methyl(hydroxymethyl)phenylphosphine with isobutyl diphenylborate yields 2,2,5-tri-phenyl-5-methyl-2-boronata-5-phosphonia-1,3-dioxane, which upon distillation, liberates formaldehyde and gives diphenylboryloxymethyl(methyl)phenylphosphine containing an active P-C-O-B system. 2. The reaction of diethylaminomethyl(methyl)phenylphosphine with isobutyl diphenylborate proceeds with intermediate hydride transfer.

This paper describes a technique for selectively extracting catecholamines from body fluids prior to quantification by high-performance liquid chromatography with electrochemical detection. The technique is a two-stage process, the first stage involves the extraction of cations from the sample whilst the second stage is a liquid-liquid extraction involving the complexation of the cationic catecholamines with diphenylborate. This technique provides a very specific extraction procedure which results in chromatograms with no interfering compounds, and gives absolute recoveries of 70–80% for noradrenaline (NA), adrenaline (A) and dihydroxybenzylamine (internal standard), with similar relative recoveries of the 3 compounds. The intra-assay coefficients of variation for the measurement of catecholamines in venous plasma taken from resting subjects, are 8–9% for both NA and A, whilst the inter-assay values are 8% for NA and 20% for A.