54313-33-6Relevant academic research and scientific papers
Designing new analogs for streamlining the structure of cytotoxic lamellarin natural products
Tangdenpaisal, Kassrin,Worayuthakarn, Rattana,Karnkla, Supatra,Ploypradith, Poonsakdi,Intachote, Pakamas,Sengsai, Suchada,Saimanee, Busakorn,Ruchirawat, Somsak,Chittchang, Montakarn
, p. 925 - 937 (2015/03/31)
Despite the therapeutic potential of marine-derived lamellarin natural products, their preclinical development has been hampered by their lipophilic nature, causing very poor aqueous solubility. In order to develop more drug-like analogs, their structure was streamlined in this study from both the cytotoxic activity and lipophilicity standpoints. First, a modified total synthetic route was successfully devised to construct a library of 59 systematically designed lamellarin analogs, which were then subjected to cytotoxicity and log P determinations. Along with the 25 first-generation lamellarins previously synthesized in our laboratory, the structure-activity and structure-lipophilicity relationships were extensively evaluated. Our results clearly indicated the additional structural requirements around the lamellarin skeleton which, when combined with those reported previously, can provide invaluable guidance for further modifications to increase the aqueous solubility of these compounds.
Facile and Divergent Synthesis of Lamellarins and Lactam-Containing Derivatives with Improved Drug Likeness and Biological Activities
Theppawong, Atiruj,Ploypradith, Poonsakdi,Chuawong, Pitak,Ruchirawat, Somsak,Chittchang, Montakarn
, p. 2631 - 2650 (2016/02/09)
With the goal to improve the aqueous solubility of lamellarins, the lactone ring in their skeleton was replaced with a lactam moiety in azalamellarins. However, the reported synthetic route produced such derivatives in very low yields. Hence, this study focused on developing an efficient simplified total synthetic scheme that could furnish both azalamellarins and the parent lamellarins from the same pyrrole ester intermediates. Subsequent comparative profiling revealed that the introduced lactone-to-lactam replacement rendered these molecules less lipophilic, whereas their cancer cytotoxicity remained equipotent to that of the parent compounds. Interestingly, their inhibitory activity was significantly enhanced towards the multifaceted GSK-3β enzyme. Our results clearly demonstrate the therapeutic potential of this promising class of marine-derived natural products and justify their further development, especially into anticancer agents.
Synthesis and initial preclinical evaluation of the P2X7 receptor antagonist [11C]A-740003 as a novel tracer of neuroinflammation
Janssen, Bieneke,Vugts, Danielle J.,Funke, Uta,Spaans, Arnold,Schuit, Robert C.,Kooijman, Esther,Rongen, Marissa,Perk, Lars R.,Lammertsma, Adriaan A.,Windhorst, Albert D.
, p. 509 - 516 (2014/08/05)
Neuroinflammation, in particular activation of microglia, is thought to play an important role in the progression of neurodegenerative diseases. In activated microglia, the purinergic P2X7 receptor is upregulated. A-740003, a highly affine and
Inverting the regioselectivity of the berberine bridge enzyme by employing customized fluorine-containing substrates
Resch, Verena,Lechner, Horst,Schrittwieser, Joerg H.,Wallner, Silvia,Gruber, Karl,MacHeroux, Peter,Kroutil, Wolfgang
, p. 13173 - 13179 (2013/01/15)
Fluorine is commonly applied in pharmaceuticals to block the degradation of bioactive compounds at a specific site of the molecule. Blocking of the reaction center of the enzyme-catalyzed ring closure of 1,2,3,4- tetrahydrobenzylisoquinolines by a fluoro moiety allowed redirecting the berberine bridge enzyme (BBE)-catalyzed transformation of these compounds to give the formation of an alternative regioisomeric product namely 11-hydroxy-functionalized tetrahydroprotoberberines instead of the commonly formed 9-hydroxy-functionalized products. Alternative strategies to change the regioselectivity of the enzyme, such as protein engineering, were not applicable in this special case due to missing substrate-enzyme interactions. Medium engineering, as another possible strategy, had clear influence on the regioselectivity of the reaction pathway, but did not lead to perfect selectivity. Thus, only substrate tuning by introducing a fluoro moiety at one potential reactive carbon center switched the reaction to the formation of exclusively one regioisomer with perfect enantioselectivity. Custom-made substrates: Employing customized substrates with a fluoro atom at the normally preferred reaction site switched the regioselectivity of the berberine-bridged enzyme. With this strategy, it was possible to get access to (S)-11-hydroxy-functionalized berbines in an asymmetric fashion by using the wild-type enzyme (see scheme). Copyright
Biocatalytic organic synthesis of optically pure (S)-scoulerine and berbine and benzylisoquinoline alkaloids
Schrittwieser, Joerg H.,Resch, Verena,Wallner, Silvia,Lienhart, Wolf-Dieter,Sattler, Johann H.,Resch, Jasmin,MacHeroux, Peter,Kroutil, Wolfgang
, p. 6703 - 6714 (2011/10/18)
A chemoenzymatic approach for the asymmetric total synthesis of the title compounds is described that employs an enantioselective oxidative C-C bond formation catalyzed by berberine bridge enzyme (BBE) in the asymmetric key step. This unique reaction yielded enantiomerically pure (R)-benzylisoquinoline derivatives and (S)-berbines such as the natural product (S)-scoulerine, a sedative and muscle relaxing agent. The racemic substrates rac-1 required for the biotransformation were prepared in 4-8 linear steps using either a Bischler-Napieralski cyclization or a C1-Cα alkylation approach. The chemoenzymatic synthesis was applied to the preparation of fourteen enantiomerically pure alkaloids, including the natural products (S)-scoulerine and (R)-reticuline, and gave overall yields of up to 20% over 5-9 linear steps.
Substituted Isoquinolinones and Quinazolinones
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Page/Page column 68, (2011/10/10)
The invention relates to substituted nitrogen containing bicyclic heterocycles of the formula (I) wherein Z is CH2 or N—R4 and X, R1, R2, R4, R6, R7 and n are as defined in the description. Such compounds are suitable for the treatment of a disorder or disease which is mediated by the activity of MDM2 and/or MDM4, or variants thereof.
Enantioselective syntheses and X-ray structures of (S)- and (R)-N-norlaudanidine: trace opium constituents
Zein, Ahmed L.,Dakhil, Otman O.,Dawe, Louise N.,Georghiou, Paris E.
experimental part, p. 177 - 180 (2010/03/04)
The enantioselective synthesis of each of the enantiomers of N-norlaudanidine, a minor Papaver somniferum opium benzyltetrahydoisoquinoline alkaloid is described. This was achieved using a chiral auxiliary-mediated Bischler-Napieralski cyclization-sodium borohydride reduction strategy. The X-ray crystal structures of each of these secondary amines are reported.
Enantioselective total synthesis and X-ray structures of the tetrahydroprotoberberine alkaloids (-)-(S)-tetrahydropalmatrubine and (-)-(S)-corytenchine
Zein, Ahmed L.,Dawe, Louise N.,Georghiou, Paris E.
scheme or table, p. 1427 - 1430 (2010/10/21)
Enantioselective total syntheses and X-ray structures of both (S)-tetrahydropalmatrubine (2) and (S)-corytenchine (3) are reported for the first time. They were both derived from (S)-N-norlaudanidine, a benzyltetrahydroisoquinoline that was synthesized with high (>95% ee) enantioselectivity using a chiral auxiliary-assisted Bischler-Napieralski cyclization/reduction approach.
Total synthesis of natural and unnatural lamellarins with saturated and unsaturated D-rings
Ploypradith, Poonsakdi,Petchmanee, Thaninee,Sahakitpichan, Poolsak,Litvinas, Nichole D.,Ruchirawat, Somsak
, p. 9440 - 9448 (2007/10/03)
(Chemical Equation Presented) Twenty-eight natural and unnatural lamellarins with either a saturated or an unsaturated D-ring were synthesized according to our developed synthetic route. The key step involved the Michael addition/ring closure (Mi-RC) of the benzyldihydroisoquinoline and α-nitrocinnamate derivatives, which provided the 2-carboethoxypyrrole intermediates in moderate to good yields (up to 78% yield). Subsequent hydrogenolysis/lactonization furnished lamellarins with a saturated D-ring in excellent yields (up to 93% yield). DDQ oxidation of the saturated lamellarin acetates led directly to the corresponding unsaturated analogues in 54-95% yield. In addition, only two steps in our developed strategy require column chromatography.
2, 6 BISHETEROARYL-4-AMINOPYRIMIDINES AS ADENOSINE RECEPTOR ANTAGONISTS
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Page/Page column 128-129, (2010/02/12)
4-Aminopyrimidine derivatives of formula (I) FORMULA heteroaryl groups, including pharmaceutically acceptable salts thereof, wherein R1 and R2 are adenosine A2A receptor antagonists useful in the treatment of movement disorders such as Parkinson's disease.
