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Summary The therapy for invasive candidiasis related to biofilms infection remains a difficult medical problem. To overcome this problem, efforts have been made to search for novel antibiofilm agents from various sources. This study investigated the in vitro antibiofilm activity of (1)-N-2-methoxybenzyl-1,10-phenanthrolinium bromide (FEN) against Candida albicans. The minimum biofilm inhibitory concentration (MBIC) and minimum biofilm reduction concentration (MBRC) were determined using the MTT (3-(4-5-dimethylthiazol-2-yl)2,5-dyphenyl tetrazolium bromide) reduction assay. Biofilms on surfaces were visualized using scanning electron microscopy (SEM). This new compound inhibited the growth of C. albicans biofilms by 80 % with an MBIC80 range from 0.5–2.0 μg/mL. The ability of FEN to reduce 50 % of a preformed biofilm was demonstrated by defining a MBRC50 range from 6.25–-12.5 μg/mL. To reduce 80 % of a preformed biofilm required higher concentrations > 200 μg/mL. In addition, SEM images showed disruption of C. albicans biofilms matrix exposed to FEN. These results indicated that (1)-N-2-methoxybenzyl-1,10-phenanthrolinium bromide has the potential to be developed as a new antibiofilm agent against C. albicans.

A rapid and efficient lithium-ion recovery from seawater established by employing calix[4]arene derivatives as extraction reagents in a microreactor system. A tripropyl-monoacetic acid derivative of calix[4]arene (1Ac) exhibited a very high extraction ability for lithium-ion within 2.00 s by using a microreactor system. The complete stripping of the lithium ions achieved with 1.0 M HCl as a stripping reagent. In a competitive metal system containing lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium and barium ions; lithium-ion selectively loaded on 1Ac. Further, lithium recovery from seawater was carried out without any pretreatment or pH adjustment in the three-step process. In the first step of the process, 1Ac extracted 100% lithium and 2.56% sodium ions from the seawater. Both lithium and sodium ions stripped with HCl in the second step and then sodium in the stripped solution selectively re-extracted with monopropyl-triacetic acid calix[4]arene derivative (3Ac) thus yielding pure lithium chloride in the aqueous phase. Both 1Ac and 3Ac calix[4]arene derivatives regenerated after the stripping process.

Removal of Pb(II) ion over several other metal ions with 25,26,27,28-tetrakis(N,N-diethylaminocarbonylmethoxy)-5,11,17,23-tetrakis(1,1,3,3-tetramethylbutyl)calix[4]arene (EATOC) from nitric acid media was investigated in a solvent extraction system. Pb(II) ion was selectively extracted over Fe(III), Co(II), Zn(II), Cu(II) and Ni(II) in the competitive model system. Further, Pb(II) ion was easily stripped from the metal-laden EATOC complex with distilled water as stripping agent. However, Pb(II) extraction and stripping in the batch system took 90 min, 24 h, respectively, to reach an equilibrium in a batch system, but it was only 2.00 s with using droplet microfluidic reactor system, which is remarkable. A rapid and selective removal of Pb(II) from a simulated wastewater effluent was also achieved. Pb(II) complexation mechanism with EATOC was investigated by using ultraviolet, Fourier transform-infrared and proton nuclear magnetic resonance spectroscopies. It was found that the complexation between Pb(II) and EATOC takes place in 1:1 stoichiometric ratio through solvation mechanism. The carbonyl oxygen atoms and phenoxy oxygen atoms of EATOC played a pivotal role in Pb(II) complexation.

International audience; Tithonia diversifolia, Cyclea barbata, Tinospora crispa, Arcangelisia flava, Pycnarrhena cauliflora are plants used in Indonesia for the traditional treatment of malaria. In the search for new antiparasitic drugs, the parts traditionally used of these 5 plants were extracted with ethanol and then fractionated with various solvents and evaluated in vitro against Plasmodium falciparum and also against Babesia divergens and Leishmania infantum. Seven crude plant extracts out of 25 tested displayed high antimalarial activities with IC50

Synthesis of propyl propanoic had been done. Propyl propanoic was synthesized via esterification of propanoic acid and 1-propanol in the presence of sulfuric acid catalyst with mole ratios of 4:3 to produce propyl propanoic. Structural characterization of products was done by means of IR, 1 H-NMR, GC and GC-MS spectrometers. Esterification of propanoic acid with 1-propanol produced propyl propanoate in 72% yield.

Heavy metal ion removal remains a serious challenge to the sustainability of our environment. In this work, a simple adsorbent, i.e., C-phenylcalix[4]pyrogallolarene bearing 12 phenolic functional groups, has been successfully synthesized and evaluated for the simultaneous adsorption of heavy metal ions in acidic media. Results showed that C-phenylcalix[4]pyrogallolarene exhibited good adsorption percentages for heavy metal ions, i.e., lead(II), chromium(III), copper(II), and nickel(II). Given that the adsorption of all metal ions was driven by the ion exchange mechanism, the adsorption process depends on the pH value of the aqueous phase, yielding the optimum pH values of 5.0, 4.9, 5.2, and 7.9 for lead(II), chromium(III), copper(II), and nickel(II) ions, respectively. The kinetics of heavy metal ion adsorption was governed by the pseudo-second order model, whereas the adsorption isotherm behavior was governed by the Langmuir model. The results also showed that the adsorption capacities for lead(II), chromium(III), copper(II), and nickel(II) were 60.97, 14.31, 8.14, and 16.86 mg g−1, respectively. The interaction between heavy metal ions and C-phenylcalix[4]pyrogallolarene was also investigated through UV–vis, FTIR, and 1H-nuclear magnetic resonance (NMR) spectroscopic studies. The findings showed that C-phenylcalix[4]pyrogallolarene is a potential adsorbent material for the simultaneous removal of heavy metal ions.

Calixarene-based cation exchange resin has been developed by methylene crosslinking of calix[6]arene hexacarboxylic acid derivative and the resin has been exploited for solid phase extraction of some toxic heavy metal ions. The selectivity order of the resin towards some metal ions follows the order Pb(II) > Cu(II) > Zn(II), Ni(II), Co(II). The maximum lead ion binding capacity of the resin was found to be 1.30 mmol g −1 resin. The loaded lead was quantitatively eluted with dilute acid solution regenerating the resin. Mutual separation of Pb(II), Cu(II) and Zn(II) was achieved by using the column packed with the resin.

Novel polyvinylcalix[4]arene resin has been synthesized by direct polymerization of calix[4]arene through vinylic groups at upper rim and an ion-exchange resin has been developed by appending carboxylic acid groups onto the resin. Adsorption behavior of the polyvinylcalix[4]arene carboxylic acid resin towards some divalent heavy metal ions has been investigated, together with its corresponding monomeric analogue as a control, in terms of effect of pH on selectivity, equilibrium time of adsorption and maximum uptake capacity. The calixarene resin was found to be superior to the monomeric analogue for adsorption ability and separation efficiency. Pb(II) ions were highly preferred over Cu(II), Zn(II), Co(II) and Ni(II) ions by calixarene resin. Size fit complementarity effect of the host cavity and the guest species was found to be the prevailing factor for specific lead ion selectivity of the resin. Surface reactive adsorption of cation on the resin due to ion exchange with carboxyl groups was sufficiently fast and significant adsorption of Pb(II) ions on the resin was achieved within 15 min. However, the equilibrium of adsorption was achieved within 4 h. Maximum lead loading capacity of calix[4]arene resin was found to be 1.82 mmol g −1 while that of the monomeric analogue was 0.064 mmol g −1 resin. Because of the resin's sensitivity to change in pH, the loaded lead was easily eluted with dilute acid solution and the resin was regenerated without any physical and chemical damage. Separation of trace amount of lead in presence of excess of zinc ions was achieved in column chromatographic experiment.

6,8-Dimethoxypyrrolo[3,2,1-hi]indole 25 has been formed by the dehydrogenation of the related tetrahydro compound 23, which in turn was formed by reduction of the related isatin 22. Approaches to achieve the cyclisation of N-hydroxyethylindoles, N-dimethylacetamidoindoles, and C7-substituted chloroacetylindoles were unsuccessful.

Two 6,8-dimethoxypyrrolo[3,2,1-hi]indole carboxylic esters were hydrolyzed and decarboxylated. In an investigation of their electrophilic substitutions, some pyrroloindoles were formylated using the Vilsmeier reagent, and acylated with oxalyl chloride followed by quenching with dimethylamine to give the glyoxylic amides. The electrophilic substitutions occur at the C2 or C4 position (α to the nitrogen atom) rather than the C1 or C5 position (β to the nitrogen atom). Four of the formyl and acyl products were reduced to the corresponding methanol derivatives. These compounds reacted on treatment with a range of acids, but pure products could not be separated from the complex mixtures.

Pyrrolo[3,2,1-hi]indoles have been formed by the aldol cyclisation of 7-formyl-N-indolylacetates. The synthetic sequence incorporates three steps from suitably activated indoles: these are alkylation at nitrogen with a bromoacetic ester, formylation at C7 and an aldol condensation between these two substituents. An X-ray crystal structure of pyrrolo[3,2,1-hi]indole 24 is described.