(2S,3S)-3-(4-Chloro-phen-yl)-8-methyl-tropane-2-carboxylic acid.

In the title compound, C(15)H(18)ClNO(2), the inter-nal torsion angles of the tropane ring are comparable to those of tropane rings in the crystal structures reported for cocaine and its derivatives. There is an intra-molecular hydrogen bond between the N atom in the tropane ring and the O atom of the carboxyl group. The crystal structure is further stabilized by many weak C-H⋯O inter-actions between the mol-ecules in the ab plane, forming a two-dimensional supra-molecular network.

A one-step automated high-radiochemical-yield synthesis of 18F-FECNT from mesylate precursor.

2Beta-carbomethoxy-3beta-(4-chlorophenyl)-8-(2-[(18)F]fluoroethyl)nortropane ((18)F-FECNT) is a potential dopamine transporter imaging agent. In this article, a new mesylate precursor was prepared and a one-step automated synthesis of (18)F-FECNT was developed. The mesylate precursor (4) was synthesized from 2beta-carbomethoxy-3beta-(4-chlorophenyl)tropane (1) by N-demethylation, hydroxyethylation followed by mesylation at a total yield of 47%. [(18)F]fluorination was performed by heating 4mg mesylate precursor and K[(18)F] in 1 ml acetonitrile at 90 degrees C for 20 min. The crude (18)F-FECNT was obtained with a radiolabeling yield of 48%. After purification by preparative high performance liquid chromatography (HPLC), the final (18)F-FECNT product was obtained with a radiochemical purity of 98.4% and a decay corrected radiochemical yield of 33+/-9% (and the uncorrected radiochemical yield was 19+/-5%, n=5). The duration of the total procedure was 80-90 min.

Quantitative analysis of 23-hydroxybetulinic acid in mouse plasma using electrospray liquid chromatography/mass spectrometry.

23-Hydroxybetulinic acid is a newly isolated derivative of betulinic acid. The agent exhibits potential anti-tumor activity and functions in this regard via apoptosis. In support of pharmacokinetic and toxicological evaluations, a new assay based on liquid chromatography/mass spectrometry (LC/MS) was developed for the quantitative analysis of 23-hydroxybetulinic acid. Sample preparation consisted of extraction of the plasma by the addition of methylene chloride followed by centrifugation. Aliquots of the supernatant were analyzed using an isocratic reversed-phase high-performance liquid chromatography (HPLC) system coupled to a negative ion electrospray mass spectrometer. Molecules of 23-hydroxybetulinic acid and the internal standard limonin were detected using selected ion monitoring at m/z 471 and 469, respectively. The limit of detection of 23-hydroxybetulinic acid was 0.05 pg (0.11 fmol) injected on-column (10 pg/mL, 5 microL injection volume), and the limit of quantitation was 10 pg (21.19 fmol, 2 ng/mL, 5 muL injection volume). 23-Hydroxybetulinic acid was stable in plasma samples at -20 degrees C for at least 3 weeks. The intra-day and inter-day coefficients of variation of the assay were 3.0 and 4.8%, respectively. The utility of the assay was demonstrated by measuring 23-hydroxybetulinicacid in mouse plasma following intragastric administration (IG) in vivo. Pharmacokinetic parameters were calculated using the 3P97 pharmacokinetic software package. A two-compartment, first-order model was selected for pharmacokinetic modeling. The result showed that after IG of 200 mg/kg 23-hydroxybetulinic acid, the plasma concentrations reached peaks at 2 h with C(max) of 3.1 microg/mL. The 200 mg/kg 23-hydroxybetulinic acid suspension IG doses were found to have long elimination half-lives of 25.6 h and low bioavailability of 2.3%. No interference was noted due to endogenous substances. These analytical methods should be of value in future studies related to the development and characterization of 23-hydroxybetulinic acid.