IAMPE: NMR-Assisted Computational Prediction of Antimicrobial Peptides.

Antimicrobial peptides (AMPs) are at the focus of attention due to their therapeutic importance and developing computational tools for the identification of efficient antibiotics from the primary structure. Here, we utilized the 13CNMR spectral of amino acids and clustered them into various groups. These clusters were used to build feature vectors for the AMP sequences based on the composition, transition, and distribution of cluster members. These features, along with the physicochemical properties of AMPs were exploited to learn computational models to predict active AMPs solely from their sequences. Naïve Bayes (NB), k-nearest neighbors (KNN), support-vector machine (SVM), random forest (RF), and eXtreme Gradient Boosting (XGBoost) were employed to build the classification system using the collected AMP datasets from the CAMP, LAMP, ADAM, and AntiBP databases. Our results were validated and compared with the CAMP and ADAM prediction systems and indicated that the synergistic combination of the 13CNMR features with the physicochemical descriptors enables the proposed ensemble mechanism to improve the prediction performance of active AMP sequences. Our web-based AMP prediction platform, IAMPE, is available at http://cbb1.ut.ac.ir/.

Synthesis of (2-mercaptoacetyl)-L-[2-14 C]tryptophan as a selective metallo-ß-lactamase inhibitor via [2-14 C]indole based on chiral pool strategy.

Metallo-beta-lactamase enzymes make bacteria resistant to a broad range of commonly used beta-lactam antibiotics. Several thiol derivatives of L-amino acids have been shown their inhibitory effects against the metallo-ß-lactamase IMP-1. In this study, (2-mercaptoacetyl)-L-tryptophan as a new inhibitor of metallo-ß-lactamases labeled with carbon-14 in the 2-position of the indole ring was prepared from [2-14 C]indole as a key synthetic intermediate based on chiral pool strategy. The overall synthesis was performed in 10 steps with the overall radiochemical yield 3.6% on the basis of the barium [14 C]carbonate as a starting material.

Synthesis of 2-(methylsulfonyl)-5-(4-(methylsulfonyl) phenyl)-4-phenyl-1H-[5-(14)C]imidazole, a selective COX-2 inhibitor, via asymmetrical benzoins.

4,5-Diarylimidazoles labeled with carbon-14 in the 5-position of the imidazole ring were prepared as a part of three-step sequence from 2-hydroxy-1-(4-(methylthio)phenyl)-2-phenyl[1-(14) C]ethanone as a key synthetic intermediate which has been synthesized from potassium [(14) C]cyanide.

High performance compatible thiazole-based polymeric blend cellulose acetate membrane as selective CO2 absorbent and molecular sieve.

Green blend membranes comprise of high thermal resistance ortho-linked thiazole-based polyimine (PM-4) including thioether linkage were fabricated in combination of glassy cellulose acetate (CA). The thermal stabilities of PMs were examined using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Morphological aspects and functional groups of the membranes were investigated via field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) analysis respectively. X-ray diffraction (XRD) and mechanical strength were determined as well. The effects of polyimine content, pressure and temperature were studied on CO2 permeability (P) and selectivity. The pressure changes revealed exponentially increases on CO2 permeability by plasticization, facilitated transfer and solution-diffusion mechanisms, but decreases on CH4 and N2 permeations. Remarkable permeation (P = 3000 Barrer) of CA/PM-4 (1:3 % w/w) and ideal selectivity ratios of CO2/N2 = 59, CO2/CH4 = 33.7 were obtained at 3 bar and 35 °C versus neat CA membrane.

Chemiluminescence characteristics of cumarin derivatives as blue fluorescers in peroxyoxalate-hydrogen peroxide system.

The chemiluminescence characteristics of seven different cumarin derivatives were studied in detail. The fluorescence and chemiluminescence spectra were compared; all cumarins used were found to act as blue fluorescers. The intensity and kinetic parameters for the chemiluminescent systems were evaluated from computer fitting of the resulting intensity-time plots. Among different cumarin derivatives used, 7-amino-4-trifluoromethylcumarin revealed the most promising characteristics as an efficient blue fluorescent emitter.

The adverse effects of methoxsalen on the oogenesis of BALB/c mice.

OBJECTIVE: Methoxsalen is a natural photoactive compound which is found in many seed plants. A number of epidermal proliferative disorders can be treated by methoxsalen along with long wave ultraviolet A (UVA). MATERIALS AND METHODS: In an experimental study, we aimed to demonstrate the effect of methoxsalen, UVA and their combination on oogenesis Balb/C mice. There were two experimental groups and a control group. The experimental groups were composed of i. a short term group with treatment duration of 15 days and ii. a long term group with treatment duration of 5 weeks. Both the long term and short term experimental groups were further subdivided into a UVA group, a methoxsalen group and a methoxsalen plus UVA group. After treatment, mature females in prosterus phase of ovarian cycle were scarified with ether, while their ovaries were removed and prepared for histological studies. RESULTS: Both macro and microscopic studies showed significant anomalies (p<0.05) among experimental group ovaries as compared to control group. The obtained results showed a significant decrease in the following factors: number and diameter of corpus lutei, Graafian follicles, diameter of granulosa cell layer and oocytes, number of primordial and primary and growing follicles, while we observed an increase in number of atretic follicle. Furthermore, our findings confirmed an increase in theca diameter only through UVA treatment. Methoxsalen also reduced circulating estrogen levels in blood serum, significantly. Other cases of teratogenecity, such as follicles with three oocytes and disorganization in corpus luteum cells were observed. CONCLUSION: The result suggests that UVA, methoxsalen and their combination cause health problems and cell injuries.

Switching the reactivity of dihydrothiopyran-4-one with aldehydes by aqueous organocatalysis: Baylis-Hillman, aldol, or aldol condensation reactions.

An aqueous medium containing catalytic amounts of a tertiary amine was employed to direct the chemoselectivity of the reaction of aldehydes with 1a. With DBU, 2 was formed at room temperature as a rare exemplary of Baylis-Hillman reactions in heterocyclic enones. DABCO alternated the pathway toward an aldol reaction to form syn/anti mixtures of 3 with the syn isomers being the major products. With Et(3)N, aldol condensation dominated.

On the cytotoxicity and status of oxidative stress of two novel synthesized tri-aza macrocyclic diamides as studied in the V79 cell lines.

Two tri-aza macrocycles as diamide derivatives of macrocyclic compounds possess a hydrophilic cavity surrounded by hydrophobic ring, which enables them to diffuse cell membrane and interfere with different living systems. In this study, we comparatively evaluated cytotoxicity effects of tri-aza dibenzo sulfoxide (TSD) and dibenzo sulfide (TTS) macrocyclic diamides in a range of doses (0.5-8mM) and the role of oxidative stress in V79 cell culture. We assessed the effects of these substances on ROS level, cellular viability, apoptosis events, activity of antioxidant enzymes including superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT), and on some macromolecules' oxidative damage end-products: malondialdehyde (MDA), dityrosine, and 8-hydroxy-deoxyguanosine (8-OH-dG) that were assessed by spectrometry and HPLC methods. Both compounds revealed cytotoxicity effects on cell culture particularly at doses >1mM after 24-h incubation. They decreased cellular viability and significantly promoted ROS generation, increased enzyme activities, and enhanced oxidative damages in which TSD was more effective. Treatment of cells with each compound alone increased significantly the percent of apoptotic events at 2 and then 4mM. Co-treatment with alpha-tocopherol (alpha-TCP) drastically reduced these events. Cells' exposure with mixture of 30 microM alpha-tocopherol and 8mM of each compound exerted significant decrease in the levels of ROS, enzyme activities, and oxidative damage biomarkers. As conclusion, our study documented the oxidative radical forming ability of the studied compounds and further strengthened the documentation of their cytotoxicity effects through lipids, proteins and DNA oxidation damages.