Synthesis and biological evaluation of novel cYY analogues targeting Mycobacterium tuberculosis CYP121A1
摘要:
The rise in multidrug resistant (MDR) cases of tuberculosis (TB) has led to the need for the development of TB drugs with different mechanisms of action. The genome sequence of Mycobacterium tuberculosis (Mtb) revealed twenty different genes coding for cytochrome P450s. CYP121A1 catalyzes a C-C crosslinking reaction of di-cyclotyrosine (cYY) producing mycocyclosin and current research suggests that either mycocyclosin is essential or the overproduction of cYY is toxic to Mtb. A series of 1,4-dibenzyl-2-imidazol-1-yl-methylpiperazine derivatives were designed and synthesised as cYY mimics. The derivatives substituted in the 4-position of the phenyl rings with halides or alkyl group showed promising antimycobacterial activity (MIC 6.25 mu g/mL), with the more lipophilic branched alkyl derivatives displaying optimal binding affinity with CYP121A1 (Pr-i K-D = 1.6 mu M; Bu-t K-D = 1.2 mu M). Computational studies revealed two possible binding modes within the CYP121A1 active site both of which would effectively block cYY from binding.
Design, Synthesis, and Characterizations of a Series of Pt<sub>4</sub> Macrocycles and Fluorescent Sensing of Fe<sup>3+</sup>/Cu<sup>2+</sup>/Ni<sup>2+</sup> Through Metal Coordination
of hard transition metal ions (Fe3+, Cu2+, Ni2+, and Mn2+) into the N4 pocket. The nonresponsive nature of the fluorescence intensity upon the addition of soft metal ions (Zn2+ and Cd2+) having d10 configuration makes it a suitable sensor for transition metal ions. The fluorescence intensity of the Ni2+ bound complex was regained when the metal was removed by a stronger chelating 2,2′-dipyridyl ligand
Axial coordination to metalloporphyrins is an important tool in the supramolecularchemistry of these entities. Metalated 5,10,15,20-tetraphenylporphyrins can be axially linked to each other with the aid of amine and diamine ligands. Seven new crystalline materials consisting of such heterogeneous coordination oligomers and polymers of Zn(II)– or Mn(III)–tetraphenylporphyrins have been prepared and
inductively coupled plasma atomic emission spectroscopy. The catalytic activity of the heterogeneouscatalyst was studied in the epoxidation of various alkenes using tert-butyl hydroperoxide as an oxidant and it showed high selectivity and catalytic reactivity. The graphene-bound copper Schiff base was successfully reused for several runs without significant loss in its catalytic activity.
Tuning of pore function and size (surface area) are two key factors that play important roles in the performance of metal–organic-frameworks (MOFs) as catalysts.
孔功能和大小(表面积)的调节是金属-有机框架(MOFs)作为催化剂性能中起重要作用的两个关键因素。
Building-up novel coordination polymer with Zn(II) porphyrin dimer: Synthesis, structures, surface morphology and effect of axial ligands
作者:S K ASIF IKBAL、SANFAORI BRAHMA、AVINASH DHAMIJA、SANKAR PRASAD RATH
DOI:10.1007/s12039-014-0686-9
日期:2014.9
Highly flexible Zn(II)1,2-bis(meso-octaethylporphyrin)ethane (1) has been used as host in which two porphyrin rings are found to be face-to-face in non-coordinating solvents. Upon addition of one relatively smaller 4,4′-dipyridine (L1) and one extended N,N′-bispyridine-4-yl-methylene ethylenediamine (L2) guest ligands, the syn conformation of 1 is switched to the anti complexes 1∙(L1)2 and 1∙L 2, respectively. Single crystal X-ray structures of all the complexes are reported in which a stable one-dimensional coordination polymer is produced only in 1∙L 2 that is, to the best of our knowledge, the first structural report of 1D-coordination polymer with porphyrin dimer. Solution structures of the complexes along with binding studies in solution between 1 and L have also been investigated. The morphology of the polymeric complex 1∙L 2 on silicon wafer surface was examined by Atomic Force Microscopy (AFM) in which the crystalline islands of well defined facets of size ranging from 200–550 nm perimeter and a height of 20–40 nm have been observed.