A 23-member library of pyrrolobenzodiazepine derivatives with vasopressin agonist activity was purified on a 100-mg per injection scale using normal-phase (NP) automated mass-directed HPLC. Analytical NP APCI-LC/MS on an experimental monolith silica CN column utilizing gradients of methanol in ethoxynonafluorobutane (hexane-like solvent) was used to provide data on chromatographic purity and ionization of the solutes. The analytical data collected were used to program a preparative LC/MS instrument for "smart" fraction collection based on the protonated molecular ion of the component of interest. Preparative HPLC was carried out on a preparative cyano column with gradients of polar organic solvents in heptane containing n-propylamine as a basic additive. Flow rates twice as high as conventional ones were used for purification of library compounds. Small aliquots of the preparative flow were mixed with makeup solvent and introduced into an APCI source of a quadrupole mass spectrometer, which triggered collection of solutes. Two methods with fixed instrument parameters were used for purification. The system utilized commercially available instrumentation and software, which provided excellent recovery and purity of the library components and appeared to be useful as a fast and efficient alternative to traditional purification technologies based on reversed-phase LC/MS.

Novel compounds combining a 5-HT 1A moiety (3-aminochroman scaffold) and a 5-HT transporter (indole analogues) linked through a common basic nitrogen via an alkyl chain attached at the 1- or 3-position of the indole were evaluated for dual affinity at both the 5-HT reuptake site and the 5-HT 1A receptor. Compounds of most interest were found to have a 5-carbamoyl-8-fluoro-3-amino-3,4-dihydro-2 H-1-benzopyran linked to a 3-alkylindole (straight chain), more specifically substituted with a 5-fluoro (( R)-(-)- 35c), 5-cyano ((-)- 52a), or 5,7-difluoro ((-)- 52g). Several factors contributed to 5-HT 1A affinity, serotonin rat transporter affinity, and functional antagonism in vitro. Although most of our analogues showed good to excellent affinities at both targets, specific features such as cyclobutyl substitution on the basic nitrogen and stereochemistry at the 3-position of the chroman moiety seemed necessary for antagonism at the 5-HT 1A receptor. Branched linkers seemed to impart antagonism even as racemates; however, the potency of these analogues in the functional assay was not desirable enough to further pursue these compounds.

Cyclic nucleotide phosphodiesterases (PDEs) play critical roles in maintaining the cellular concentration cGMP and cAMP. These key secondary messengers modify the activation of cyclic nucleotide dependent protein kinases that phosphorylate various substrates including ion channels and transcription factors to regulate a myriad of physiological processes. PDE4 is a cAMP specific phosphodiesterase which has been suggested to play a key role in the regulation of PKA/CREB pathway. The PKA/CREB pathway impacts a wide range of physiological responses, including those involved in learning and memory. Inhibition of PDE4 is therefore an attractive approach to development of novel therapies for neurodegenerative disease such as Alzheimer’s disease. To discover novel potent inhibitors of PDE4, we have expressed and purified the catalytic domain of human PDE4B. The purified protein was analyzed by N-terminal sequencing, mass spectral analysis and stability studies. Our findings indicated that PDE4B catalytic domain was unstable and partially degraded to a smaller more stable conformation. The purified PDE4B preparation, therefore, consisted of a mixture of intact and degraded protein, which may be problematic for activity and crystallization studies. We developed a scheme to generate a stable PDE4B catalytic domain by driving the degradation to completion. The resulting preparation was homogenous and of high specific activity. This high quality PDE4B protein was used for binding assays and structural studies.

Over 195 4-alkyl and 4,4-dialkyl 1,2-bis(4-chlorophenyl)pyrazolidine-3,5-dione derivatives were synthesized, utilizing microwave accelerated synthesis, for evaluation as new inhibitors of bacterial cell wall biosynthesis. Many of them demonstrated good activity against MurB in vitro and low MIC values against Gram-positive bacteria, particularly penicillin-resistant Streptococcus pneumoniae (PRSP). Derivative 7l demonstrated antibacterial activity against both Gram-positive and Gram-negative bacteria. Derivatives 7f and 10a also demonstrated potent nanomolar Kd values in their binding to MurB.

Several photolabile sirolimus analogs have been synthesized. All ot the compounds showed an antiproliferative effect in a mitogen-induced thymocyte proliferation assay. Compounds 3 and 4 were shown to be equipotent to sirolimus in a murine skin allograft model; they should thus be useful for investigating the in viva details of the signal transduction pathway(s) modulated by sirolimus. The immunosuppressive effect of analogs 3-5 is corroborated by their ability, as part of an FKBP12 complex, to bind a sirolimus effector protein (SEP).

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTConformational Changes of Rapamycin and Analogs upon Complexing with FKBP Associated with Activity: An Application of Second Derivative CD SpectroscopyYanqiu Chen, Peng Zhou, Nina Berova, Hongzhi Zhang, Koji Nakanishi, Amedeo Failli, Robert J. Steffan, Katherine Molnar-Kimber, and Thomas J. CaggianoCite this: J. Am. Chem. Soc. 1994, 116, 6, 2683–2684Publication Date (Print):March 1, 1994Publication History Published online1 May 2002Published inissue 1 March 1994https://doi.org/10.1021/ja00085a084Request reuse permissions Article Views150Altmetric-Citations10LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (281 KB) Get e-Alertsclose Get e-Alerts