590-88-5Relevant academic research and scientific papers
Reinvestigating Old Pharmacophores: Are 4-Aminoquinolines and Tetraoxanes Potential Two-Stage Antimalarials?
Terzi?, Natasa,Konstantinovi?, Jelena,Tot, Miklo?,Burojevi?, Jovana,Djurkovi?-Djakovi?, Olgica,Srbljanovi?, Jelena,?tajner, Tijana,Verbi?, Tatjana,Zlatovi?, Mario,Machado, Marta,Albuquerque, Inês S.,Prudêncio, Miguel,Sciotti, Richard J.,Pecic, Stevan,D'Alessandro, Sarah,Taramelli, Donatella,?olaja, Bogdan A.
supporting information, p. 264 - 281 (2016/01/29)
The syntheses and antiplasmodial activities of various substituted aminoquinolines coupled to an adamantane carrier are described. The compounds exhibited pronounced in vitro and in vivo activity against Plasmodium berghei in the Thompson test. Tethering a fluorine atom to the aminoquinoline C(3) position afforded fluoroaminoquinolines that act as intrahepatocytic parasite inhibitors, with compound 25 having an IC50 = 0.31 μM and reducing the liver load in mice by up to 92% at 80 mg/kg dose. Screening our peroxides as inhibitors of liver stage infection revealed that the tetraoxane pharmacophore itself is also an excellent liver stage P. berghei inhibitor (78: IC50 = 0.33 μM). Up to 91% reduction of the parasite liver load in mice was achieved at 100 mg/kg. Examination of tetraoxane 78 against the transgenic 3D7 strain expressing luciferase under a gametocyte-specific promoter revealed its activity against stage IV-V Plasmodium falciparum gametocytes (IC50 = 1.16 ± 0.37 μM). To the best of our knowledge, compounds 25 and 78 are the first examples of either an 4-aminoquinoline or a tetraoxane liver stage inhibitors.
Positioning and configuration of key atoms influence the topology of [13]-macrodiolides
Ma, Jun,Peczuh, Mark W.
, p. 7414 - 7422 (2013/09/02)
Key atoms at specific positions along the ring govern the shape, or topology of a group of [13]-macrodiolides. Here we report the synthesis of these macrocycles and their characterization by functional and structural methods. The [13]-macrodiolides are organized by three four-atom planar units that help to rigidify them and one hinge atom that enables the planar units to orient themselves. The driving force for the organization of the structures is the minimization of steric strain on groups attached to the key atoms. When the key atom is a stereocenter, a macrocycle with planar chirality is observed. An alternative cup-like topology arises when the key atom bears two alkyl groups. Additionally, the key atoms can work in a coordinated fashion to guide one topology over another. The synthesis relied on an acylation-ring closing metathesis sequence. Rigidity was demonstrated by variable-temperature NMR experiments and diastereoselective epoxidation reactions. X-ray crystal structures of representative [13]-macrodiolides served as the basis of the structural observations made. The results provide a framework for the design of new macrocycles with well-defined structures as well as for understanding some general principles that influence the topology of natural product macrocycles.
Synthesis of tricyclic nitrogen heterocycles by a sequence of palladium-catalyzed N-H and C(sp3)-H arylations
Guyonnet, Mathieu,Baudoin, Olivier
supporting information; experimental part, p. 398 - 401 (2012/02/15)
A range of tricyclic nitrogen heterocycles were synthesized in a straightforward and efficient manner via a sequence involving palladium-catalyzed N-arylation and C(sp3)-H arylation as the key steps. Whereas the C(sp3)-H arylation furnished fused 6,5,6-membered ring systems efficiently, the formation of the more strained 6,5,5-membered systems proved to be more challenging and required a subtle adjustment of the reaction conditions.
Thermally induced opening of the diaziridine ring in 6-aryl-2-methyl-1,5- diazabicyclo[3.1.0]hexanes
Koptelov,Saik
, p. 1501 - 1506 (2007/10/03)
Thermally induced opening of the diaziridine ring in 6-aryl-2-methyl-1,5- diazabicyclo[3.1.0]-hexanes at the carbon-nitrogen bond is characterized by low regioselectivity; isomerization of unstable intermediate azomethine imines leads to mixtures of the corresponding 1-arylmethyl-5-methyl-4,5-dihydro-1H-pyrazoles and 1-arylmethyl-3-methyl-4,5-dihydro-1H-pyrazoles at a ratio of ～6:5. Analogous regioselectivity in opening of the three-membered ring is observed in the presence of phenyl isocyanate. In this case, adducts with cis arrangement of the aryl and methyl groups are formed as the major products (cis/trans ratio ～3:1).
Reduction of Heterocycles with Nickel-Aluminum Alloy
Lunn, George
, p. 1043 - 1046 (2007/10/02)
Pyrazines, pyridazines, isoxazoles, oxazole, 4-methylpyrimidine, and indole are reduced by nickel-aluminum alloy in potassium hydroxide solution.The reaction is simple to carry out and does not require special apparatus or hydrogen atmospheres.The products were the fully hydrogenated species although benzene rings were not attacked. 4-Methylpyrimidine gave 1,3-diaminobutane and oxazole gave 2-(methylamino)ethanol.It was found that the reaction frequently exhibited an induction period.
