The potent dihydropyrazole insecticide RH 3421 (methyl 1-(N-(α,α,α,-trifluoro-p-tolyl)carbamoyl-3-(4-chlorophenyl)-4-methyl-2-pyrazolin-4-ylcarboxylate), which has previously been shown to block voltage-gated and neurotoxin-activated sodium currents through sodium channels in insect nerves an...

The sodium channel blocker tetrodotoxin partially inhibited [3H]batrachotoxinin-A 20-α-benzoate binding to rat brain synaptosomes. This inhibition results from a decrease in the apparent affinity of the radioligand, which indicates that sites 1 and 2 of the sodium channel are not independent as...

Recent investigations in our laboratory showed that voltage-gated sodium channels (VGSCs) in brain are sensitive to inhibition by various synthetic cannabinoids and endocannabinoids. The present experiments examined the effects of the cannabinoid-1 (CB1) receptor agonist CP-55,940 and ethyl arac...

Batrachotoxin and its derivatives have become important tools for the study of membrane excitability by virtue of their effects on voltage-sensitive sodium channels. Recent studies have shown that the 2,4-dimethylpyrrole carboxylate ester normally occurring in the 20-α position of batrachotoxin...

Since ethanol has local anesthetic activity its effect was examined in vitro on the scorpion toxin-enhanced specific binding of [3H]batrachotoxinin A 20-α-benzoate ([3H]BTX-B) to the gating complex in sodium channel preparations from mouse brain cortex by equilibrium and kinetic experiments. Et...

T. L. Casebolt and G. B. Brown. Batrachotoxinin-A-ortho-azidobenzoate: a photoaffinity probe of the batrachotoxin binding site of voltage-sensitive sodium channels. Toxicon31, 1113–1122, 1993.—Batrachotoxin (BTX) is one of a group of potent lipid-soluble neurotoxins which binds voltage-sensiti...

Attempts were made to find whether [3H]batrachotoxinin A 20-α-benzoate provides a specific probe for measuring interactions of local anesthetics with the sodium channel complex. [3H]Batrachotoxinin A 20-α-benzoate binding, [14C]guanidine and 22Na uptake were investigated in rat brain crude syn...

A [3H]batrachotoxinin A-20α-benzoate ([3H]BTX-B) binding assay was used to investigate the interaction of two ginseng aglycones (20(S)protopanaxadiol and 20(S)protopanaxatriol) and Rh2 (a monoglucoside of 20(S)protopanaxadiol) with voltage-gated sodium channels in mouse brain. All compounds inh...

A number of putative endocannabinoids were found to modify the binding of [3H]batrachotoxinin A-20α-benzoate ([3H]BTX-B) to site 2 on voltage-gated sodium channels of mouse brain and achieve functional inhibition of sodium channels in vitro. 2-Arachidonoyl-glycerol (2-AG), arachidonoyl glycerol...

Optoelectronic property enhancement of poly(9,9′-di-n-octylfluorenyl-2.7-diyl) (PFO) by different weight ratios of TiO2 nanoparticles (NPs) is demonstrated. The solution blending method was used to prepare the PFO/TiO2 nanocomposite. The microstructure of the composites was determined using X-r...

Nanocomposite thin films of poly(9,9-di-n-hexylfluorenyl-2,7-diyl) (PHF) with 10–50 wt% perovskite-structured SrTiO3 nanoparticles (designated as PHF:SrTiO3) were prepared by spin coating. The photoluminescence (PL) properties of the nanocomposites thin films were studied. The incorporation of ...

The rapid discovery of a pharmacological chaperone toward human α-Gal A for the treatment of Fabry disease is described. Two polyhydroxylated pyrrolidines with the (3R,4S,5R) configuration pattern underwent rapid substituent diversity by conjugating the primary aminomethyl moiety of each with a...

The light purple heartwood of Acacia saxatilis contains (+)-2,3-trans-3,4-trans- and (+)-2,3-trans-3,4-cis-diastereoisomers of 8-methoxy-7,j',4'-trihydroxy- and 7,3′,4′-trihydroxyflavan-3,4-diols as major components. Evidence was also obtained of the first 3-methyl ether of metabolit...

The formation of the compounds C6H6 · xBN(i-C3H7)2 (x = 1–6) from the reaction of dichloro(diisopropylamino)borane with sodium/potassium alloy in 1,2-dimethoxyethane, has been confirmed by mass spectrometric studies (high resolution, field ionisation and collision activation using “linked sca...

A sample of stored O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothiolate (VX), known to contain many impurities, was studied by combined capillary column gas chromatography-mass spectrometry under both electron impact and chemical ionization conditions. More than twenty sample components...

Packed capillary column liquid chromatography (LC)–electrospray mass spectrometry (ESI–MS) was used for the first time to detect and identify O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothiolate (VX) and its degradation products, including compounds containing a P-CH3 bond, bis(diisop...

Photolysis of 2,5-dichloro-3,6-bis(dialkylamino)-[1,4]benzoquinone (1) at 254 nm or 300–500 nm produces the corresponding cyclized products (2) via the electron transfer-proton transfer sequence in a variety of solvents in quantitative yields within 10 min. In contrast, photolysis of 2,5-dichlo...

Malarial parasites rely on the digestion of hemoglobin during the intra-erythrocytic stage. The enzymatic degradation of hemoglobin yields amino acids for parasite survival, and free heme which is detoxified by conversion to an aggregate of dimeric heme known as hemozoin. Xanthones have been fou...

Formation constants of calcium complexes with malonate (mal2−), in the ranges 10 ⩽ t ⩽ 50°C and 0.05 ⩽ I ⩽ 0.9 mol dm−3, were determined by means of alkalimetric titrations in aqueous solution. The species found in this system were [Ca(mal)]0 and [Ca(Hmal)]+; also, the hydrolysis of Ca2+ was ta...

Heterogeneous chiral Jørgensen–Hayashi catalyst promotes enantioselective Michael addition of malonates at cinnamic aldehydes. In combination with Ca(OTf)2, it provides high yields (up to 78%) and excellent enantiomeric excesses (up to 99%) of the adducts.