Architecture of the rings of 5-arylidenerhodanine derivatives versus P-gp inhibition

5-Arylidene derivatives of rhodanine show various biological activities. The new crystal structures of five derivatives investigated towards ABCB1 efflux pump modulation are reported, namely, 2-[5-([1,1′-biphenyl]-4-ylmethylidene]-4-oxo-2-thioxothiazolidin-3-yl)acetic acid dimethyl sulfoxide monosolvate, C₁₈H₁₃NO₃S₂·C₂H₆OS ( 1 ), 4-[5-([1,1′-biphenyl]-4-ylmethylidene]-4-oxo-2-thioxothiazolidin-3-yl)butanoic acid, C₂₀H₁₇NO₃S₂ ( 2 ), 5-[4-(benzyloxy)benzylidene]-2-thioxothiazolidin-4-one, C₁₇H₁₃NO₂S₂ ( 3 ), 4-{5-[4-(benzyloxy)benzylidene]-4-oxo-2-thioxothiazolidin-3-yl}butanoic acid, C₂₁H₁₉NO₄S₂ ( 4 ), and 5-[4-(diphenylamino)benzylidene]-2-thioxothiazolidin-4-one, C₂₂H₁₆N₂OS₂ ( 5 ). Compounds 1 and 3 – 5 crystallize in the triclinic space group P, while 2 crystallizes in the monoclinic space group P2₁/n, where the biphenyl moiety is observed in two positions (A and B). Two molecules are present in the asymmetric unit of 5 and, for the other four compounds, there is only one molecule; moreover, 1 crystallizes with one dimethyl sulfoxide molecule. The packing of the molecules containing a carboxyl group ( 1 , 2 and 4 ) is determined by O—H…O hydrogen bonds, while in the other two compounds ( 3 and 5 ), the packing is determined by N—H…O hydrogen bonds. Additionally, induced-fit docking studies have been performed for the active compounds to investigate their putative binding mode inside the human glycoprotein P (P-gp) binding pocket.     

Antibacterial effect,efflux pump inhibitory (NorA,TetK and MepA) of Staphylococcus aureus and in silico prediction of α, β and δ-damascone compounds

ObjectiveThe present study aimed to evaluate the antibacterial effect and inhibitory capacity against NorA, TetK and MepA efflux pump of Staphylococcus aureus multiresistant by in vitro and in silico approach of α, β and δ-damascone compounds.ResultsThe compounds α, β and δ-damascone showed a clinically relevant effect against S. aureus ATCC 6538 standard strain. A modulating effect was also observed in association with antibiotics against MDR strains. Regarding the inhibition of the efflux pump, the compounds showed a modulating effect with antibiotics, against SA-1199, SA-1199B, SA IS-58 and K2068. Only δ-damascone demonstrated an efflux pump inhibitory effect. Regarding ADME properties, α, β and δ-damascone showed similar physicochemical properties with good pharmacokinetic characteristics, such as lipophilicity, oral bioavailability and low toxicity. In addition, they exhibited the binding energy and Ligand Efficiency (LE) ?81.17 (5.4), ?77.48(-5.4) and ?64.55 (-5.1), which shows good interactions with the critical residues of the MepA receptor.ConclusionsFrom the results it is concluded that the compounds α, β and δ-damascone do not have antibacterial activity, but show a modulating effect in association with antibiotics, as well as not showing direct activity on the efflux pump, but they do have a modulating effect with antibiotics and with EtBr (α and β-damascone).     

Adjustable low dynamic pumps based on hydrogels

This paper discusses the suitability of hydrogel actuators as drives of automatic pumps for long-term drug release. We demonstrate that such actuators can execute a defined task if several functional units are connected serially. Investigated functions of this pump are the adjustability of the time-delay from the initial operation up to the beginning of the drug release, opening the sterile drug ampoule, and the drug release at a specified timeframe. The described parameters to influence the pump behaviour are satisfying only for realization of continuous working devices. An outlook of the development of programmable pulsate pumps is given.