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Two new coordination polymers namely, [(AgCN)4LS]n (1) and [(AgCN)3LN]n (2), were successfully synthesized by the reaction of AgNO3 and cyanide as a co-anion with LS[1,1′-(hexane-1,4-diyl)bis(3-methylimidazoline-2-thione] and LN[1,1,3,3-tetrakis(3,5-dimethyl-1-pyrazole)propane] ligands in order to use them for the preparation of magnetic nanocomposites with MnFe2O4 nanoparticles by an efficient and facile method. They were then well characterized via numerous techniques, including elemental analysis, FT-IR spectroscopy, TGA, PXRD, SEM, TEM, EDX, VSM, BET, ICP, and single-crystal X-ray diffraction. The considered polymers and their magnetic nanocomposites with nearly the same antibacterial activity demonstrated a highly inhibitive effect on the growth of Gram-negative (Escherichia coli, Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus, Bacillus subtilis) bacteria. By considering the simple separation and recyclable characters of the magnetic nanocomposites, these materials are suitable to be used in biological applications.

Five dinuclear organotin(IV) complexes, R4Sn2La (R = Me, Ph) and R4Sn2Lb (R = Me, Ph and Bu) have been synthesized from reaction of R2SnCl2 with 2,4′- and 2,2′-bis-substituted diphenylamine arylidene hydrazones, H4La and H4Lb, respectively. The synthesized compounds have been investigated by elemental analysis and IR, 1H NMR, and 119Sn NMR spectroscopy. The structures of Me4Sn2Lb and Ph4Sn2Lb have been also confirmed by X-ray crystallography. The results show that the fully deprotonated bis-hydrazone ligand provides two contiguous ONO tridentate domains that coordinate to the two SnR2 moieties in the enolate form. Each tin atom in the complexes adopts a five-coordinate environment. Ligands and complexes showed no antibacterial activity against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. However, both ligands and their methyl complexes were found to degrade DNA, an observation that adapt with the mode of interaction suggested by molecular docking.

The TiO 2 hollow spheres were synthesized using a green, cheap, and easy process, in which carbonaceous spheres were chosen as the removable template. The prepared materials were characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Energy-dispersive X-ray spectroscopy (EDX), Atomic force microscopy (AFM), Fourier Transform Infrared Spectroscopy (FTIR), and Brunauer–Emmett–Teller (BET) analysis. According to the results, the obtained mesoporous TiO 2 hollow spheres demonstrated an external diameters less than 200 nm with shell thickness around 40 nm. The antibacterial activities of the TiO 2 hollow spheres were evaluated against gram-positive ( Bacillus subtilis and Staphylococcus aureus ) and gram-negative ( Escherichia coli and Pseudomonas aeruginosa ). No antibacterial activity was found for TiO 2 hollow spheres in the used concentrations. TiO 2 hollow spheres were loaded with gentamycin as a selected antibiotic to magnify their benefits in biomedical applications. TiO 2 hollow spheres exhibited good antibiotic carrier activity for the direct delivery of gentamicin, which was attributed to interaction between gentamicin and surface due to their larger specific surface area, more abundant porous structure, and their spherical morphology. The application of TiO 2 hollow spheres as gentamicin carrier undoubtedly opens an avenue to use hollow sphere materials in other drug delivery applications.

Mesoporous silica nanoparticles (MSNs) were prepared by sol-gel method and functionalized with 3-aminopropyltriethoxysilane. Schiff base grafted mesoporous silica nanoparticle was synthesized by the condensation of 2-hydroxy-3-methoxybenzaldehyde and amine-functionalized MSNs. The latter material was then treated with Cu(II) and Ni(II) salts separately to obtain copper and nickel complexes anchored mesoporous composites. The newly prepared hybrid organic-inorganic nanocomposites have been characterized by several techniques such as FT-IR, LA-XRD, FE-SEM, TEM, EDS, BET and TGA. The results showed all samples have MCM-41 type ordered mesoporous structure and functionalization occurs mainly inside the mesopore channel. The presence of all elements in synthesized nanocomposites and the coordination of Schiff base via imine nitrogen and phenolate oxygen were confirmed. MSNs and all functionalized MSNs have uniform spherical nanoparticles with a mean diameter less than 100 nm. The as-synthesized mesoporous nanocomposites were investigated for antibacterial activity against Gram-positive (B. subtilis and S. aureus) and Gram-negative (E. coli and P. aeruginosa) bacteria, as carrier for gentamicin and also for immobilization of DNase, coagulase and amylase enzymes. MSN-SB-Ni indicated bacteriocidal effect against S.aureus and all compounds were found to be good carrier for gentamicin. Results of enzyme immobilization for DNase and coagulase and α-amylase revealed that supported metal complexes efficiently immobilized enzymes.

Two bis-hydrazone, H4La and H4Lb, have been synthesized from reaction of 5,5′-methylene-bis-salicylaldehyde with benzhydrazide and furan-2-carbohydrazide, respectively. New organotin(IV) complexes, (R2Sn)2L [L = La: R = Me (1), Ph (2); L = Lb: R = Me (3), Ph (4)] have been synthesized by reaction of dihydrazone ligands with R2SnCl2 (R = Me or Ph). The synthesized compounds have been investigated by elemental analysis and IR, 1H NMR, and 119Sn NMR spectroscopy. The structures of 1 and 2 have been also confirmed by X-ray crystallography. The results show that the dihydrazone acts as a tetrabasic ligand in the enolic form and is coordinated to two SnR2 moieties via ONO donor domains by the imine nitrogen and phenolic and enolic oxygen atoms. All complexes are binuclear and the coordination number of both tin is five. The in vitro antibacterial activity of ligands and complexes has been evaluated against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria and compared with standard drugs. The synthesized compounds also have been investigated for the chromosomal and plasmid DNA cleavage activity. The complexes significantly inhibited bacterial growth, while none of compounds showed DNA cleavage activity.

A 3-D cadmium-based coordination polymer, [CdCl2L]n (1) (where L = 1,1-(1,6-hexanediyl)bis(1,3-dihydro-3-methyl-1H-imidazole-2-thione), was synthesized and structurally characterized. The capability of the polymer as an efficient sorbent for Congo red (CR) removal from aqueous solution has been evaluated. Compound 1 has a tetrahedral arrangement with a CdS2Cl2 core. L in 1 is bidentate to two neighboring CdII centers via the methimidazole sulfurs to create 1D chains propagating along the c-axis. The remaining coordination sites are occupied by two terminal chlorides. The chains are further stabilized by intermolecular C–H⋯Cl hydrogen bonds between the chlorides and hydrogens of the imidazole rings. Parallel chains stack in the 3-D structure. The CdII polymer sorbent was characterized by infrared spectroscopy, elemental analysis, UV–vis, solid fluorescence and X-ray single-crystal diffraction. Sorption kinetics were studied by three kinetic models, second order, Elovich and intraparticle diffusion. The results indicate that the mechanism of the sorption process followed Elovich kinetic model. Sorption equilibrium was also studied with Langmuir, Temkin, and Freundlich isotherm models. The sorption process followed the Temkin isotherm. MIC, MBC, and DNA cleavage activities of 1 were also studied. Furthermore, the UV–vis and solid state fluorescence spectra of 1 were measured.

Two new isostructural Zn(II) and Cd(II) coordination polymers, namely {[Zn 2 (bbit) 3 Cl 2 ][ZnCl 4 ]} n ( 1 ) and {[Cd 2 (bbit) 3 Cl 2 ][CdCl 4 ]} n ( 2 ), have been synthesized and structurally characterized. These compounds represent the first examples of cationic coordination polymers with a tetrahedral MS 3 Cl [M = Zn(II) and Cd(II)] repeating unit. Each of these units is bridged to three symmetry-related ones through the bbit ligands. The 2D [M 2 (bbit) 3 Cl 2 ] 2+ cationic networks stack in an ABAB… sequence along the c -direction. From MIC, MBC and DNA cleavage activity studies, it can be concluded that the title compounds possess antibacterial activity.

Three organotin(IV) complexes, Ph4Sn2L (1), Me2Sn(H2L) (2) and Bu2Sn(H2L) (3) have been formed from reaction of R2SnCl2 (R = Ph, Me and Bu) with a multiprotic dihydrazone, 1,5-bis((2-hydroxynaphthaldehyde) thiocarbohydrazone (H4L). The synthesized compounds have been investigated by elemental analysis, IR, 1H NMR, and 119Sn NMR spectroscopy. The structure of 1 has been also confirmed by X-ray crystallography. The results show 1 is binuclear and fully deprotonated thiocarbohydrazone supplies two different tridentate dianionic domains, NNO and ONS, for coordination to two diphenyltin(IV) moieties. Coordination number of both tin(IV) center is five and it is maintain in solution. In 1 and 2 only one part of ligand as doubly deprotonated ONS donor was coordinated with tin and a mononuclear organotin complex with coordination number of five was formed. The in vitro antibacterial activity of ligand and complexes has been evaluated against Gram-positive (B. subtilis and S. aureus) and Gram-negative (E. coli and P. aeruginosa) bacteria and compared with standard drugs. The synthesized compounds also have been investigated for the chromosomal and plasmid DNA cleavage activity. All complexes significantly inhibited bacterial growth and completely degrade the treated DNA.

International audience; This study shows the inactivation of antibacterial and dye removal in aqueous solution via photocatalysis with an easy fabrication route of silver deposited titanium dioxide/cobalt ferrite composite nanoparticles through a three-stage process applied under ultrasonic irradiation. An adsorption kinetic and equilibrium isotherm were investigated by four kinetic and five isotherm models. Then, photocatalytic potential and antibacterial activity were assessed, respectively, by photodegradation of cationic dye under UV light and four bacteria employing MIC and MBC indices coupled to SPM observation, which illustrated that the bactericidal effect is desirable to inhibit growth. Moreover, the nanocomposite can be easily isolated from the solution via magnetic decantation for removing catalytic pollutants.

Two new diorganotin(IV) complexes, Me2SnL and Ph2SnL, have been synthesized from the reaction of Me2SnCl2 and Ph2SnCl2 with the hydrazone H2L [H2L = (Furan-2-yl) (5-hydroxy-3-methyl-5-phenyl-4,5-dihydro-1H-pyrazol-1-yl)-methanone] derived from furan-2-carbohydrazide and benzoylacetone. The new compounds have been characterized by elemental and spectroscopic analyses. The crystal structures of the monohydrate form of the ligand and of the Me2SnL derivative have been also determined by X-ray crystallography. Experimental evidences confirm the existence of the hydrazone ligand exclusively in cyclic form in both solution and solid state. On coordination to tin the hydrazone undergoes a ring opening reaction and a doubly deprotonation to act as a tridentate ligand via imine nitrogen and enolic oxygens. The tin atom in the complexes is five coordinate with geometry between square-pyramidal and trigonal-bipyramidal. The in vitro antibacterial activity of ligand and its complexes has been evaluated against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. The interaction between compounds with bacterial DNA was also studied by molecular docking. Our findings indicate that diphenyltin(IV) complex, by binding to DNA via minor groove to TATA sequence in genes upstream, has good activities along with the standard antibacterial drugs. Our agarose-gel electrophoresis experiments show that the ligand exert DNA cleavage, while Me2SnL and Ph2SnL did not.

In this research, we report a straightforward route for the synthesis of a cationic supramolecular structure via covalently anchoring an ionic liquid-containing pyridinium moiety onto c-methylcalix[4]resorcinarene. Antibacterial activity of the new functionalized c-methylcalix[4]resorcinarene was evaluated against Gram-positive and Gram-negative bacteria. Surprisingly, this compound exhibited a selective antibacterial effect on Gram-positive bacteria, which is very important from the industrial and medicinal point of view. These preliminary results are attractive for the development of a new antibacterial agent.

In the present contribution, we have described a facile fabrication of silver-deposited silanized cobalt ferrite composite (CoFe2O4/SiO2/Ag) through a three-step procedure. A pre-synthesized CoFe2O4 was first coated with silica using Stober method and then silver nanoparticles were deposited onto the surface of silica shell. After characterization of this three-component composite by various techniques, such as FT-IR, XRD, SEM, EDX, TEM and VSM, it was impregnated with streptomycin antibiotic. The antibacterial activity of CoFe2O4/SiO2/Ag alone and in combination with streptomycin was investigated against some Gram-positive and Gram-negative bacteria employing disc diffusion assay. It was observed that the bactericidal effect of this composite, evaluated through the diameter of inhibition zones, was enhanced in combination with streptomycin. This clearly indicates synergistic effect of streptomycin on CoFe2O4/SiO2@Ag composite. The present study has demonstrated that the newly synthesized CoFe2O4/SiO2/Ag composite, when combined with streptomycin, becomes an excellent antibacterial agent. The as-made composite can be readily isolated from aqueous solution via magnetic decantation avoiding contamination of the environment.

A three-component composite consisted of graphene oxide, cobalt ferrite, and silver nanoparticles has been prepared by a facile method and fully characterized. The antibacterial activity of this composite has been greatly enhanced after being combined with ciprofloxacin drug. This clearly showed the occurrence of a strong synergistic effect between ciprofloxacin and the Ag NPs in the composite. The ciprofloxacin-conjugated composite was found to be a potent antimicrobial agent while having rather low cytotoxicity and high stability. The studies based on field emission scanning electron microscopy (FESEM) analysis and zeta potential measurement have revealed that the composite sticks to the bacterial cell wall causing irreversible cell damage. This multifunctional magnetic nanocomposite was also examined as drug delivery system for ciprofloxacin in solutions with different pH. It was observed that the release of ciprofloxacin in this system is pH-sensitive with gradual and controlled manner. Mechanisms for the synergistic effect and drug release behavior, as well as explanation for the antibacterial action, of the nanocomposite were also demonstrated.

The new diorganotin(IV) complexes R2SnL (L = La: R = Me 1, Ph 2; L = Lb: R = Me 3, Ph 4, L = Lc: R = Me 5, Ph 6, Bu 7) have been synthesized by the reaction of the hydrazone ligands N′-(5-bromo-2-hydroxybenzylidene) isonicotinohydrazide (H2La), N′-((2-hydroxynaphthalen-1-yl)methylene) isonicotinohydrazide (H2Lb) and N′-(2,4-dihydroxybenzylidene) isonicotinohydrazide (H2Lc) with diorganotin(IV) dichloride. The synthesised compounds have been investigated by elemental analysis, together with IR, 1H and 119Sn NMR spectroscopy. The structures of H2La, H2Lb and 3 have also been confirmed by X-ray crystallography. On the basis of these data, H2La and H2Lb are present in the keto-amine tautomeric form and intermolecular N–H⋯N hydrogen bonds form 1D chain structures. The hydrazone ligands act as tridentate dibasic in the enol form and are coordinated via the imine nitrogen, phenolate and enolate oxygen atoms. The in vitro antibacterial activity of the ligands and their complexes has been evaluated against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria and compared with standard antibacterial drugs. The R2SnLc complexes exhibited greater activities than the other compounds.

The organotin(IV) complexes, SnPh2La (1), SnMe2La (2), SnBu2La (3), SnPh2Lb (4), SnMe2Lb (5), SnPh2Lc (6), SnMe2Lc (7), and SnBu2Lc (8) were obtained by reaction of SnR 2Cl2 (R = Ph, Me, and Bu) with 1-(5-bromo-2-hydroxybenzylidene)-4-phenylthiosemicarbazide (H2La), 1-((2-hydroxynaphthalen-1-yl)methylene)-4-phenylthiosemicarbazide (H2Lb), and 1-(2-hydroxy-3-methoxybenzylidene)-4-phenylthiosemicarbazide (H2Lc). The synthesized complexes have been investigated by elemental analysis, IR, 1H NMR, and 119Sn NMR spectroscopy. The data show that the thiosemicarbazone acts as a tridentate dianionic ligand and coordinates via the thiol group, imine nitrogen, and phenolic oxygen. The coordination number of tin is 5. The in vitro antibacterial activities of the ligands and their complexes have been evaluated against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria and compared with the standard antibacterial drugs. [Supplemental materials are availabl...

A new silver coated cobalt ferrite nanocomposite, Ag@CoFe2O4, was prepared by a two-step procedure. In the first step, cobalt ferrite nanoparticles were synthesized by a combustion method using glycine as a fuel. This ferrite was then coated with nanosilver via chemical reduction of Ag+ solution. The as-synthesized Ag@CoFe2O4 was characterized by X-ray diffraction, transmission electron microscopy, and vibrating sample magnetometer. The antibacterial activity of this composite was investigated against some Gram-positive and Gram-negative bacteria and compared with those of silver nanoparticles and some standard antibacterial drugs.

Three new water-soluble organotin complexes R2Sn(5-BrSalGT)Cl [R = Ph, Me] and Ph2Sn(2-OHNaphGT)Cl have been synthesized by the reaction of R2SnCl2 (R = Ph or Me) with Schiff bases derived from condensation of Girard-T reagent with 5-bromosalicylaldehyde and 2-naphthaldehyde, (5-BrH2SalGT)Cl (1) and (2-OHH2NaphGT)Cl (2). The synthesized compounds have been investigated by elemental analysis, conductometric measurements, IR, 1H NMR, and 119Sn NMR spectroscopy. These data show that the deporotonated ligand is coordinated to Sn(IV) via ONO atoms and six-coordinate zwitterionic complexes are formed. The ligands and their complexes were investigated for their in vitro toxicity against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. The results show remarkable antibacterial activity against the studied bacteria. All complexes exhibit more inhibitory effects than the parent ligand. The anticancer activity of all compounds were also performed on HN5 cell line and (2-OHH2NaphGT)Cl with concentration of 1 mg mL−1 was found to show higher anticancer activity than other compounds.

Four new diorganotin(IV) complexes, R2SnL (L = La: R = Me 1, Ph 2; L = Lb: R = Me 3, and Ph 4), have been synthesized by reaction of hydrazone ONO donors, 5-bromo-2-hydroxybenzaldehyde furan-2-carbohydrazone (H2La) and 2-hydroxynaphthaldehyde furan-2-carbohydrazone (H2Lb) with diorganotin(IV) dichloride in the presence of a base. The compounds have been investigated by elemental analysis and IR, 1H NMR, and 119Sn NMR spectroscopies. Spectroscopic studies show that the hydrazone is a tridentate dianionic ligand, coordinating via the imine nitrogen and phenolic and enolic oxygens. The structures of H2Lb and 3 have also been confirmed by X-ray crystallography. The results show that the structure of 3 is a distorted square pyramid with imine nitrogen in apical position. The in vitro antibacterial activities of ligands and complexes have been evaluated against gram-positive (Bacillus cereus and Staphylococcus aureus) and gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. H2La and H2Lb show n...

Five organotin(IV) complexes, were obtained by reaction of SnR 2 Cl 2 (R = Ph, Me, Bu) with ONO donor Schiff bases. The synthesized complexes have been investigated by elemental analysis and IR, 1 H NMR, and 119 Sn NMR spectroscopy. These data show that the Schiff base acts as a tridentate dianionic ligand and coordinates via the imine nitrogen and two oxygen atoms. The X-ray crystallography of complex 4 shows a dimeric structure for this molecule. The in vitro antibacterial activities of the Schiff bases and their complexes have been evaluated against Gram-positive ( Bacillus subtilis and Staphylococcus aureus ) and Gram-negative ( Escherichia coli and Pseudomonas aeruginosa ) bacteria and compared with the standard antibacterial drugs.

The Schiff bases H2La, H2Lb, and H2Lc have been prepared from the reaction of 2-amino-4-chlorophenol with acetylacetone, benzoylacetone, and dibenzoylmethane, respectively. Organotin(IV) complexes [SnPh2(La)] (1), [SnPh2(Lb)] (2), [SnPh2(Lc)] (3), and [SnMe2(Lc)] (4) have been synthesized from the reaction of SnPh2Cl2 and SnMe2Cl2 with these Schiff bases. The synthesized complexes have been characterized by elemental analysis and FT-IR, 1H, 13C, and 119Sn NMR spectroscopy. Spectroscopic data suggest the Schiff bases are completely deprotonated and coordinated tridentate to tin via imine nitrogen and phenolic and enolic oxygen atoms; the coordination number of tin is five. Thermal decomposition of the complexes has been studied by thermogravimetry. The in vitro antibacterial activities of the Schiff bases and their complexes have been evaluated against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. H2La, H2Lc, and all co...

Objective: To guide for selection of plants with antibacterial activity for further phytochemical works on the isolation and identification of the active compounds. Methods: Ethanolic extracts of 3 species from Malvaceae family were evaluated by agar disc diffusion method for antibacterial activity against some gram-positive and gram-negative bacteria (Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus epidermidis, Staphylococcus a areas, Klehsiella pneumoniae, Salmonella typhi, Bacillus cereus, Bacillus anthracis, Escherichia coil and Streptococcus pyogenes). The extracts were obtained from aerial parts of Hibiscus rosa (H. rosa)-sinensis (leaf and flower). Alcea rosea (A. rosea) L. (leaf and flower) and Malva neglecta (M. neglecta Wallr flower). Results: These extracts had inhibitory effects at different concentrations (0.05. 0.10, 0.20 and 0.40 g/mL) against above mentioned bacteria. Escherichia coil was the most resistant strain. The highest inhibitory zone was showed by ethanolic extract of M. neglecta against Staphylococcus epidermudis (22 mm) and followed by ethanolic extract from flower of H. rosa against Staphylococcus epidermidis and Staphylococcus aureus (20 mm). The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values against Staphylococcus epidermidis were equal (MIC=MBC=5 mg/mL for M. neglecta extract and for H. rosa extract MIC=MBC=20 mg/mL). Conclusions: These findings suggest that these native plants have good antibacterial properties that can be used for infection control and treatment and could also be as new source for antibiotics discovery and infection treatment.

Objective: To explore the antibacterial effect of the alcoholic extracts of aerial parts of Teucrium polium, native in Iran on some pathogenic bacteria. Methods: Antibacterial activity of ethanolic extract (50 to 400 mg/mL) and methanolic extract (400 and 600 mg/mL) was evaluated by disc diffusion method. Results: The ethanolic extract results showed that Bacillus anthracis was the most sensitive species, while Escherichia coli and Proteus mirabilis were more resistant than others. In the case of the methanolic extract, Bordetella bronchiseptica was the most sensitive and Proteus mirabilis and Arcanobacterium pyogenes were the most resistant species. The hydroalcoholic extract of Teucrium polium had a relatively satisfactory effect on Salmonella typhi. The minimal inhibitory concentration (MIC) of Staphylococcus aureus and Salmonella typhi was 40 mg/mL and Bordetella bronchiseptica and Bacillus anthracis was 10 mg/mL. The minimal bactericidal concentration (MBC) against Bacillus anthracis was 10 mg/mL while against other species were not found (＞200 mg/mL). The methanolic extract had also synergistic effect with methicillin, vancomycin against Staphylococcus aureus and with novobiocin against Salmonella typhi. Conclusions: These results suggest that this plant contains relatively good antibacterial activity and it can be used as a source of antiseptic compounds for medicinal uses.

Problem statement: Callistemon citrinus and Albizia lebbeck are two kind of native plants in Khoozestan province in Iran, according to the agree ment that medicinal plant could be replaced the medicine we are trying to determine the antibacteri al effect of the named plants. Approach: The antibacterial properties of ethanolic and methanoli c extract of Callistemon citrinus leaf and Albizia lebbeck leaf was studied against different pathogenic bac teria including Streptococcus pyogenes , Bacillus cereus , Bacillus anthracis , Salmonella typhi , Kelebsiella pneumoniae , Streptococcus epidermidis , Escherichia coli , Pseudomonas aeruginosa and Listeria monocytogenes by disc diffusion method. The samples collected fro m young trees from Ahvaz city at may 2009. Results: The extract of C. citrinus showed significant activity against the majority o f bacteria which is comparable with standard antibiotics. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) for hydroalcoholic extract of Callistemon have been determined also for four bacteria; S. pyogenesis , S. typhy , B. anthrasis , S. typhy , Albizia lebbeck extract despite previous reports didn't have any significant effect . Conclusion: According to the good effects of Callistemon citrinus on Bacillus species it has antiseptic effects and could be use d as a therapeutic agent and therefore, it appears to be a potent anti microbial agents that could be considered as a medicinal plant.

Background: Medicinal plants have now attracted more attention due to their antibacterial activity and also increasing antibiotic resistance among bacteria. Native plants of each region are potential resources for this purpose. Objectives: The aim of the present study was to detect the antibacterial effect of Eucalyptus microtheca (Myrtaceae family) which is currently used as an antibacterial fumigation medicine. Materials and Methods: Using standard disk diffusion method, the antibacterial activity, MIC, and MBC indexes of alcoholic extracts from this plant were tested on some pathogenic bacteria. The structural changes following the exposure to these extracts were also investigated in test bacteria. Results: Significant antibacterial activity was found against gram-positive and gram-negative bacteria, which among them, Escherichia. coli and Pseudomonas. aeruginosa showed the most sensitivity and Staphylococcus. aureus the least. The value of MIC and MBC for both extracts was 8 mg/mL for E. coli, while they were 8 mg/mL and 16 mg/mL for Bacillus cereus, respectively. Both MIC and MBC values of methanolic and ethanolic extracts against P. aeruginosa were 8 and 16 mg/mL respectively. SEM revealed structural changes in the affected bacteria that suggest the cell wall was the main target site of active constituents. Conclusions: It can be concluded that this plant has potential application in infection control, especially against E. coli and P. aeruginosa and regarding their recent reported epidemic, this plant can be a good choice for antibiotic discovery.

Background: Cassia fistula, is a flowering plant and a member of Fabaceae family. Its leaves are compound of 4 - 8 pairs of opposite leaflets. There are many Cassia species around the world which are used in herbal medicine. Objectives: This study was designed to examine in vitro anti-bacterial activity of methanolic and ethanolic extracts of C. fistula native to Khuzestan, Iran. Materials and Methods: The microbial inhibitory effect of methanolic and ethanolic extracts of C. fistula was tested on 3 Gram positive: Bacillus cereus, Staphylococcus aureus and S. epidermidis and 5 Gram negative: Salmonella Typhi, Kelebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis bacterial species using disc diffusion method at various concentrations. The minimum inhibitory and bactericidal concentrations (MIC and MBC) were measured by the tube dilution assay. Results: The extract of C. fistula was effective against B. cereus, S. aureus, S. epidermidis, E. coli and K. pneumoniae. The most susceptible microorganisms to ethanolic and methanolic extracts were E. coli and K. pneumoniae, respectively. Also B. cereus and S. aureus showed the least sensitivity to ethanolic and methanolic extracts, respectively. The MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) of ethanolic extracts against S. aureus, E. coli, S. epidermidis and K. pneumoniae were also determined. Conclusions: With respect to the obtained results and regarding to the daily increase of the resistant microbial strains to the commercial antibiotics, it can be concluded that these extracts can be proper candidates of antibacterial substance against pathogenic bacterial species especially S. aureus, E. coli, K. pneumoniae and S. epidermidis.

The aim of this study was to examine the antimicrobial activity of the methanolic extract of Torilis leptophylla was tested on eleven bacteria (Bacillus anthracis, Bacillus subtilis, Bacillus pumilus, Staphylococcus aureus, Bacillus licheniformis, Brucella melitensis, Escherichia coli, Salmonella typhi, Proteus mirabilis, Bordetella bronshiseptica and Pseudomonas aeruginosa). Tested extract was effective against all bacteria but not B. subtilis. Consequently, the ethanolic extract had antibacterial activity on some pathogens thus confirming their use in folk medicine.

Objective To assess the antibacterial activity of eight Iranian plant extracts against Staphylococcus aureus ( S. aureus ) strains which were isolated from infected patients. Methods The studied strains were isolated from urine, stool, blood and wound of infected patients and identified by biochemical tests. In further, the antibacterial activity of 8 ethanolic local plant extracts including Querqus brantii ( Q. brantii ), Ziziphus spina-christi ( Z. spina-christi ), Peganum harmala ( P. harmala ), Oliveira decumbens ( O. decumbens ), Galium tricornutum ( G. tricornutum ), Vitex pseudo negundo ( Vi. pseudo negundo ), Salvia officinalis ( S. officinalis ), Vaccaria pyramidata ( V. pyramidata ) were then evaluated using agar disc diffusion method. Results A total of 9 isolates were isolated and identified as S. aureus . Antibacterial profile of the strains showed that the strains were resistant to methicillin and cefixime. The highest antibacterial activity against the studied strains were belong to Q. brantii, P. harmala, Z. spina-christi and O. decumbens vent extracts with 11-40 mm, 15-28 mm, 8-26 mm and 10-20 mm of diameters, respectively. Intermediate antibacterial activity was exhibited by G. tricornutum and Vi. pseudo negundo against some of the studied strains with 7-20 mm and 7-13 mm of diameters, respectively. Noteworthy, out of 9 studied strains; 6 and 2 of them were resistant to the G. tricornutum and Vi. pseudo negundo extracts, respectively. The S. officinalis and Va. pyramidata , however, showed no antibacterial activity against the studied strains. Conclusions The Q. brantii, P. harmala, Z. spina-christi and O. decumbens extracts were shown to possess strong antibacterial activity against methicillin and cefixime resistant S. aureus strains and can be considered as the promising natural antibiotics for treating the studied strains.