Synthesis of (3-nitro-2-oxo-benzaldehyde thiosemicarbazonato)-zinc(II) complexes: the position of nitro group in phenyl ring alters antimicrobial activity against K. pneumoniae 1, S. typhimurium 2, MRSA and C. albicans.

The basic purpose of this investigation was to explore the effect on antimicrobial activity of a nitro group at an ortho- versus para-position in the 2-hydroxy-phenyl ring of nitro-salicylaldehyde-N-substituted thiosemicarbazone (X-NO2-stscH2-N1HR, X = 3 or 5; stsc-stands for salicyladehyde thiosemicarbazone) complexes with zinc. Reactions of zinc(ii) acetate with 3-nitro-salicylaldehyde-N-substituted thiosemicarbazones (3-NO2-stscH2-N1HR) and 2,2-bipyridine, or 1,10-phenanthroline as co-ligands, yielded complexes of stoichiometry, [Zn(3-NO2-stsc-N1HR)(N,N-L)] {L, R: bipy, H, 1; Me, 2; Et, 3; Ph, 4; phen, H, 5; Me, 6; Et, 7; Ph, 8}. The thio-ligands coordinate to the metal as dianions (deprotonation of -OH and -N2H moieties) through O, N3 and S donor atoms in distorted trigonal bipyramid geometry (4, 5, 7: τ = 0.718-0.576) or in distorted square pyramid geometry (8: τ = 0.349). ESI-mass spectrometry supported the formation of molecular ion peaks. Complexes displayed fluorescence with λmax = 438-473 nm. It was found that these five-coordinated [Zn(3-NO2-stsc-N1HR)(N,N-L)] complexes showed high antimicrobial activity against methicillin resistant S. aureus (MRSA), Klebsiella pneumoniae 1, Salmonella typhimurium 2 and C. albicans vis-à-vis that of 5-NO2-stscH2-N1HR zinc complexes reported earlier. However, in comparison, the antimicrobial activity of 5-nitro complexes against S. aureus was high relative to 3-nitro complexes in the present case.

Recent advances in theranostic polymeric nanoparticles for cancer treatment: A review.

Nanotheranostics is fast-growing pharmaceutical technology for simultaneously monitoring drug release and its distribution, and to evaluate the real time therapeutic efficacy through a single nanoscale for treatment and diagnosis of deadly disease such as cancers. In recent two decades, biodegradable polymers have been discovered as important carriers to accommodate therapeutic and medical imaging agents to facilitate construction of multi-modal formulations. In this review, we summarize various multifunctional polymeric nano-sized formulations such as polymer-based super paramagnetic nanoparticles, ultrasound-triggered polymeric nanoparticles, polymeric nanoparticles bearing radionuclides, and fluorescent polymeric nano-sized formulations for purpose of theranostics. The use of such multi-modal nano-sized formulations for near future clinical trials can assist clinicians to predict therapeutic properties (for instance, depending upon the quantity of drug accumulated at the cancerous site) and observed the progress of tumor growth in patients, thus improving tailored medicines.

Synthesis, structures, spectroscopy and antimicrobial properties of complexes of copper(II) with salicylaldehyde N-substituted thiosemicarbazones and 2,2'-bipyridine or 1,10-phenanthroline.

Among the biometals (Cu, Co, Ni-cofactors in many enzymes), copper derivatives of O, N, S-donor salicylaldehyde thiosemicarbazones have received considerable attention owing to their potential biological applications. Eight new complexes of salicylaldehyde-N-substituted thiosemicarbazones [5-MeO-2-HO-C6H4-C(2)(H)N(3)-N(2)H-C(1)(S)-N(1)HR; R = Me, H2L(1); Et, H2L(1), Ph, H2L(3), H, H2L(4)] with copper(II), namely, [Cu(κ(3)-O,N,S-L)( κ(2)-N,N-L')] {(L)(2-) = (L(1))(2-), L' = bipy, 1, phen, 2; (L)(2-) = (L(2))(2-), L' = bipy, 3, phen, 4; (L)(2-) = (L(3))(2-), L' = bipy, 5, phen, 6; (L)(2-) = (L(4))(2-), L' = bipy, 7, phen, 8} have been isolated. Complexes have slightly distorted square pyramidal geometry around the metal center (τ parameter = 0.243-0.357) and display weak to intense fluorescence in the region, 375-475 nm. These copper complexes have shown significant growth inhibitory activity (antimicrobial activity) against Staphylococcus aureus (MTCC740), methicillin resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae 1 (MTCC109), Shigella flexneri (MTCC1457), Pseudomonas aeruginosa (MTCC741) and Candida albicans (MTCC227). The activity against MRSA is an interesting observation as the commercially available gentamycin is found to be inactive against this bacterial strain. Specifically complex 5 formed by 5-methoxysalicylaldehyde-N-phenylthiosemicatbazone has shown novel antimicrobial activity against various bacteria and yeast investigated.