New 1,3,4-bisthiadiazolines: Synthesis, characterization and antimicrobial evaluations
摘要:
The bisthiadiazolines 4a-4g have been synthesized in good yields from the cyclization reactions of bisthiosemicarbazones 3a-3g with acetic anhydride. The condensation reaction of dibenzaldehydes 2a-2g with thiosemicarbazide in alcoholic medium provided 3a-3g and former were obtained from the O-alkylation of 3-hydroxybenzaldehyde with suitable 1,omega-dibromoalkanes under alkaline conditions in the presence of dry EtOH/DMF. The intermediates 3a-3g and bishetrocyclics 4a-4g were also screened for their in vitro antimicrobial activities against seven bacterial strains (Klubsellia pneumoniae, Pseudomonas aeruginosa, Escherichia coli, Straphylococcus aureus, Bacillius subtilis, Pseudomonas fluorescens and Streptoccus pyrogens) and five fungi strains (Aspergillius Janus, Pencillium glabrum, Fusarium oxysporum, Aspergillus sclerotiorum, Aspergillus niger). The compounds 3f, 3g, 4f & 4g were found to be significantly active against the tested microorganisms. (C) 2012 Elsevier B.V. All rights reserved.
13C‐NMR, and ESI‐MS). The newly prepared compounds were screened for their antimicrobial activity against seven bacterial and five fungal strains. The DNAphotocleavage potential of these compounds was also evaluated by using agarose gel electrophoresis, and bispyranopyrazoles 4b, 4d and 4e exhibited significant level of DNA photocleavage activity.
Self-assembly of molecular devices containing a ferrocene, a porphyrin and a quinone in a triple macrocyclic architecture
作者:Richard W. Wagner、Philip A. Brown、Thomas E. Johnson、Jonathan S. Lindsey
DOI:10.1039/c39910001463
日期:——
Porphyrinogen self-assembly is compatible with a structurally diverse set of meta-linked dialdehyde building blocks, providing rapid access under gentle conditions to porphyrins bearing redox-active units positioned in a 3-dimensional architecture.
Investigation of the one-flask synthesis of porphyrins bearing meso-linked straps of variable length, rigidity, and redox activity
作者:Richard W. Wagner、Thomas E. Johnson、Jonathan S. Lindsey
DOI:10.1016/s0040-4020(97)00327-x
日期:1997.5
The reactions of 18 dialdehydes have been examined in the two-step one-flask room temperature porphyrin synthesis. Efficient alkylation methods were established for the reaction of diols and diacids with m-bromomethylbenzaldehyde Dialdehydes linked at the o,o'- or m,m'-positions were converted to strapped porphyrins in yields up to 25%, while the one p,p'-linked dialdehyde that was examined failed to give porphyrin. The resulting porphyrins bear straps joining adjacent meso-positions rather than across the face of the porphyrin. Dialdehydes incorporating rigid groups provided improved yields in some but not all cases. The yield of strapped porphyrin exhibited a maximum at 10(-2) M reactant concentrations. The o,o'-strapped porphyrins exist as atropisomers thai are sufficiently stable to interconversion at room temperature to be separable chromatographically. No atropisomers of m,m'-strapped porphyrins could be separated, though some could be observed by H-1 NMR spectroscopy. For two different m,m'-strapped porphyrins, the Delta G double dagger values for interconversion of the atropisomers were found to be 66 and 68 kJ/mol. The outer rings in these strapped porphyrins range in size from 14 to 24 atoms. Five porphyrins with bridging redox-active groups (ferrocene or anthraquinone) have been prepared in one-flask reactions, including a porphyrin bearing one ferrocene and one anthraquinone in straps across adjacent meta-substituted phenyl sites. (C) 1997 Elsevier Science Ltd.
Bis(oxyphenylene)benzimidazoles: A novel class of anti-Plasmodium falciparum agents
作者:Annie Mayence、Jean Jacques Vanden Eynde、Marcel Kaiser、Reto Brun、Nigel Yarlett、Tien L. Huang
DOI:10.1016/j.bmc.2011.10.039
日期:2011.12
A small library of 26 2,2'-[alkane-alpha,omega-diylbis(oxyphenylene)] bis-1H-benzimidazoles has been prepared and evaluated against Giardia intestinalis, Entamoeba histolytica, Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani, and Plasmodium falciparum. Among the tested compounds, eight derivatives (17, 19, 20, 24, 27, 30, 32 and 35) exhibited an anti-Plasmodium falciparum activity characterized by IC50 values in the range of 180-410 nM (0.11-0.21 mu g/mL) and selectivity indexes (IC50 rat skeletal myoblasts L6 cells vs IC50 P. falciparum K1 strain) varying between 92 and more than 450. Two of the eight novel drug leads, namely compounds 19 and 32, were also active against G. intestinalis and L. donovani with selectivity indexes of 122 and > 164 respectively. (C) 2011 Elsevier Ltd. All rights reserved.
Covalently bound dimers of glycopeptide antibiotics