A new series of 6-substituted 2-aminobenzothiazole derivatives were synthesized and screened in vitro as potential antimicrobials. Almost all the compounds showed antifungal activity. In particular, compounds 1n,o, designed on the basis of molecular modeling studies, were the best of the series, showing MIC values of 4e8 mg/mL against Candida albicans, Candida parapsilosis and Candida tropicalis. None of the two compounds did show any cytotoxicity effect on human THP-1 cells.

llypcrtbrin ir a natural phloroglucinol tlraî hao baen knswn for îhe trc6lm{:!î of dsprer'niop. llyperforin clisplay* alro antibacr€rial. antiprolifcranr and ontiangiogenic activity. Synrhetie dsrivatives ofhypcrlnrin have also recsfltly been reportsd lo porisc$j incrcared bioactivity. The clinicnl applicttiols arE lirnitcd by tlre hydrophobie characteristics and the irstability nfthc molecule, In this rcview wc diserss abqut somc of thc dcrivrtive$ of hyperforin (nrirtoforin, tetrohydrohyperfbrin onil octalrydrohperlbrin) that dcmonsrratcd promising antitunror uetivity. Anrong the${], octahyrJrohyper{orin alsn pa$set$cf antibsdîsrial aqtivity 4Baif|rit both the planktonic and biofilm saatc$ ofbact$ria.

Bacterial biofilms are organized communities of microorganisms, embedded in a self-produced matrix, growing on a biotic surface and resistant to many antimicrobial agents when associated with a medical device. These biofilms require the development of new strategies for the prevention and treatment of infectious disease, including the potential use of natural products. One interesting natural product example is Hypericum, a plant genus that contains species known to have antimicrobial properties. The major constituent of Hypericum perforatum is an unstable compound named hyperforin (1); for this reason it was not believed to play a significant role in the pharmacological effects. In this investigation a hydrogenated hyperforin analogue (2) was tested on several ATCC and clinical isolate strains, in their planktonic and biofilm form (Staphylococcus aureus, MRSA, and Enterococcus faecalis). Compound 2 was effective against planktonic and biofilm cultures, probably due to higher stability, showing the percentage of cells killed in the range from 45% to 52%. These results are noteworthy from the point of view of future development of these polyprenylated phloroglucinols as potential antibiotics.

We determined the in vitro antifungal activity of liposomal amphotericin B (L-AmB) against 604 clinical yeast isolates. Amphotericin B deoxycholate (D-AmB) was tested in parallel against all the isolates. Susceptibility testing was performed according to the Clinical and Laboratory Standards Institute (CLSI) M27-A3 method. Overall, L-AmB was highly active against the isolates (mean MIC = 0.42 μg/ml; MIC90= 1μg/ml; 97.2% of MICs were ≤ 1μg/ml) and comparable to D-AmB (mean MIC = 0.48μg/ml; MIC90= 1μg/ml; 97.3% of MICs were ≤ 1μg/ml). The in vitro activity of D-AmB and L-AmB was correlated (R2 = 0.61; exp (Coef.) = 2.3; 95% IC= 2.19-2.44, p<0.001). Candida albicans (mean MICs of D-AmB and L-AmB, 0.39 μg/ml and 0.31 μg/ml, respectively) and Candida parapsilosis (mean MICs of D-AmB and L-AmB, 0.38 μg/ml and 0.35 μg/ml, respectively) were the species most susceptible to the agents tested, while Candida krusei (currently named Issatchenkia orientalis) (mean MICs of D-AmB and L-AmB, 1.27 μg/ml and 1.13 μg/ml, respectively) was the least susceptible. The excellent in vitro activity of L-AmB may have important implications for empirical treatment approaches and support its role in treatment of a wide range of invasive infections due to yeasts

This study furnishes deeper insights to previous works on anidulafungin, demonstrating the potent activity against Candida strains planktonic cells and biofilms. Candida sp., associated with many biomaterial-related infections, give rise to infective pathologies typically associated with biofilm formation. We recently determined the in vitro antifungal activities of echinocandin anidulafungin in association with some antifungal drugs against some Candida strains in their planktonic states. A total of 11 Candida strains biofilms were tested in this study: six Candida albicans, three C. parapsilosis and two C. tropicalis. All yeast isolates and ATCC strains were stored at 20 1C in glycerol stocks and were subcultured on antimicrobial agent-free Sabouraud dextrose agar plates. MIC endpoints were determined colorimetrically by using the indicator 2,3-bis(2-methoxy-4-nitro-5- sulphophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide (XTT) with menadione as electron-coupling agent. The activity of anidulafungin was assessed using in vitro microbiological model relevant for clinical practice. Anidulafungin showed a strong activity in vitro against both planktonic and biofilms cells, and our study confirms that high anidulafungin concentrations might establish paradoxical growth effect in C. albicans and C. tropicalis biofilms.

The aim of this study was to verify the existence of synergistic antibacterial effect between four essential oils (Aniba rosaeodora, Melaleuca alternifolia, Origanum vulgare, and Pelargonium graveolens) individually combined with the antibacterial drug Gentamicin. We investigated the effectiveness in vitro of the association of essential oil/Gentamicin, against fifteen different strains of Gram positive and Gram negative bacteria. The antibacterial effects of these oils in combination with Gentamicin were evaluated by using the MHB microdilution method, while gas chromatography (GC) and GC/Mass spectrometry were used to analyze the chemical composition of the oils. A synergistic interaction was ob- served against all tested strains with the associations between the essential oils Aniba rosaeodora/Gentamicin and Pelar- gonium graveolens/Gentamicin. In particular a very strong synergistic interaction was observed against Acinetobacter baumannii ATCC 19606 (FIC index = 0.11). In contrast, the essential oils Origanum vulgare and Melaleuca alternifolia in association with Gentamicin were less effective on bacterial species growth. In vitro interaction can improve the antimi- crobial effectiveness of the Gentamicin and may contribute to reduce its dose correlated to side effects.

In this paper the authors investigated a synergistic antimycotic effect between four antifungal drugs Ampho- tericin B, Fluconazole, Tioconazole, and Flucytosine individually combined with Anidulafungin compound. This latter is considered a drug of choice in the treatment of fungal infections; it has good activity both in vitro and in vivo against yeasts and moulds, as Candida and Aspergillus. The goal of this study was to evaluate the in vitro interaction of Anidula- fungin in the synergic combinations with previous reported drugs against 12 Candida strains according to CLSI M27-A3 protocol. A synergistic interaction was observed against the most antifungal strains; in particular an increasing of the an- timycotic efficacy was obtained from the association between Anidulafungin and Amphotericin B or Fluconazole (Mix- ture 4:6). In contrast the association Tioconazole/Anidulafungin was less effective on fungal species growth. The antimy- cotics MIC reduction values were more evident against some strains as C. glabrata, C. krusei, C. tropicalis and C. parap- silosis.

Enterococcus faecalis is a Gram-positive commensal inhabitant of the intestinal tract of humans, animals, and insects. However, it is also an opportunistic pathogen and has emerged as a leading cause of hospital-acquired extraintestinal infections. Fluoroquinolones have been frequently used to treat E. faecalis infections, and the emergence of fluoroquinolone-resistant E. faecalis strains has recently been reported in several countries. Thus, the identifications of new antibiotics specifically directed to E. faecalis may be envisaged. In this paper, a new series of N-1,3-benzothiazol-2-ylbenzamides have been designed, synthesized, and evaluated for their in vitro antimicrobial activities. Among the tested compounds, 3i was active against E. faecalis. © 2013 Domenico Armenise et al.

By using the Suzuki-Miyaura protocol, a simple straightforward synthesis of functionalized 2-arylaziridines has been developed. By means of this synthetic strategy from readily available ortho-, meta- and para-bromophenylaziridines and aryl-or heteroarylboronic acids, new aziridines could be obtained. The cross-coupling reactions occurred without ring opening of the three membered ring. Preliminary results on the antimicrobial activity of the heterosubstituted biaryl compounds have been also included.