Sonodynamic Effects of a Novel Ether-Group Modified Porphyrin Derivative Combined With Pulsed Low-Intensity Ultrasound on PC-9 Cells

Sonodynamic therapy (SDT) is a developing modality for cancer treatment based on the synergistic effect of ultrasound and chemical compounds which are known as sonosensitizers. The development of more efficient sonosensitizers has become an urgent issue in this field. In this study, a novel porphyrin derivative (BBTPP) mediated SDT was evaluated on PC-9 cells. Pulsed low-intensity ultrasound (PLIU) was used for its little thermal and mechanical damage. The accumulation of drugs in cells was evaluated through porphyrin fluorescence, and the cytotoxicity of BBTPP was evaluated using a cell counting kit-8 assay. The sonodynamic effect was investigated by Hoechst 33342/PI and Annexin V-FITC/PI double staining, which showed an apoptotic rate of 18.87% in the BBTPP-SDT group, as compared with 1.71%, 1.4%, 1.57%, 3.61%, 11.18% in the control, BBTPP, hematoporphyrin monomethyl ether (HMME), ultrasound, and HMME-SDT groups, respectively. The sono-toxic effect of BBTPP was significantly superior to HMME. Our results showed that BBTPP-SDT resulted in much higher intracellular reactive oxygen species (ROS) and lipid peroxidation levels which were evaluated by 2′,7′-dichlorodihydrofluorescein diacetate (H2DCFDA) and Liperfluo assay, respectively. The expressions of Bax, Bcl-2, caspase-9, caspase-8, and cleaved caspase-3 proteins were evaluated to investigate the apoptotic mechanism of BBTPP-SDT. The results of this study showed that the combination of BBTPP and PLIU induced the generation of ROS, resulting in lipid peroxidation, and activated both the extrinsic and intrinsic apoptotic pathways of PC-9 cells. Our results also suggested that the ether group introduced in the side chain of porphyrin could enhance the sono-toxicity of porphyrin-based sensitizers under the sonication of PLIU. These results supported the possibility of BBTPP as a promising sonosensitizer, and an appropriate side chain could enhance the sono-sensitivity of porphyrins.

Carbon Dioxide Separation by Polyethylene Glycol and Glutamic Acid/Polyvinyl Alcohol Composite Membrane

In this study, Polyvinyl alcohol (PVA) blended with Polyethylene glycol (PEG), Monosodium glutamate (MSG) and Glutamic acid (GA) was cast on a reverse osmosis membrane to form a composite membrane. It is expected that the ether group can increase the CO2 affinity of the membrane. Sodium tetraborate (Borax) as a crosslinker can increase membrane basicity and glutamic acid (salt) can provide an enhanced transport mechanism, thereby improving the permeability and selectivity of carbon dioxide. FTIR spectra show that the thickness of coating is sufficiently low, while SEM results show that PVA-PEG series have a dense surface, and particles are observed on the surface of MSG/GA series. The gas permeance and separation performance of the composite membrane was tested using a single gas. Results showed that CO2 had higher permeance (GPU) at lower pressure differential. PEG with an ether group had the greatest effect on improving CO2 permeance and selectivity. However, MSG and GA with amine groups could not effectively improve CO2 selectivity due to solubility. The best coating solution was provided by PVA-PEG-1.2. The CO2 selectivity of the composite membrane was 10.05 with a pressure differential of 1.00 bar in a humid environment and no obvious deterioration was observed over a 10-day period. Borax can improve selectivity, water absorption, and thermal stability while avoiding the need for high temperature and long crosslinking time of aldehydes, which makes it possible to be used in a PVA carbon dioxide separation membrane.

Diastereoselective Addition of Prochiral Nucleophilic Alkenes to a-Chiral N-Sulfonyl Imines

The Lewis acid catalyzed addition of prochiral E and Z allyl nucleophiles to chiral -alkoxy N-tosyl imines is described. Alkene geometry is selectively transferred to the newly formed carbon-carbon bond, resulting in stereochemical control of C2, C3, and C4 of the resulting 2-alkoxy-3-N-tosyl-4-alkyl-5-hexenes. The C3 and C4 diastereoselectivity (dr) is influenced by the geometry of the alkene, size of N-sulfonyl substituent, and steric bulk of the substituted -alkoxy ether group. This work demonstrates that three of the four possible diastereomers can be synthesized in high diastereoselectivity and high yields using the current methods. A mechanistic computational analysis to elucidate the high selectivity is also presented.

Antimicrobial Activity of Gemini Surfactants with Ether Group in the Spacer Part

Due to their large possibility of the structure modification, alkylammonium gemini surfactants are a rapidly growing class of compounds. They exhibit significant surface, aggregation and antimicrobial properties. Due to the fact that, in order to achieve the desired utility effect, the minimal concentration of compounds are used, they are in line with the principle of greenolution (green evolution) in chemistry. In this study, we present innovative synthesis of the homologous series of gemini surfactants modified at the spacer by the ether group, i.e., 3-oxa-1,5-pentane-bis(N-alkyl-N,N-dimethylammonium bromides). The critical micelle concentrations were determined. The minimal inhibitory concentrations of the synthesized compounds were determined against bacteria Escherichia coli ATCC 10536 and Staphylococcus aureus ATCC 6538; yeast Candida albicans ATCC 10231; and molds Aspergillus niger ATCC 16401 and Penicillium chrysogenum ATCC 60739. We also investigated the relationship between antimicrobial activity and alkyl chain length or the nature of the spacer. The obtained results indicate that the synthesized compounds are effective microbicides with a broad spectrum of biocidal activity.

Dynamics of chemiluminescence in the small intestine during anesthetic preconditioning in hemorrhagic hypotension

Введение. Ведущим патогенетическим фактором массивной кровопотери является гипоксия, инициирующая активацию процессов свободнорадикального окисления (СРО) в органах и тканях и системный воспалительный ответ. Показано, что одним из универсальных звеньев формирования множественной органной дисфункции при кровопотере является изменение проницаемости кишечной стенки с транслокацией микрофлоры и токсинов в системный кровоток на фоне реперфузии. В последнее время внимание исследователей привлекает эффект анестетического прекондиционирования, в том числе при операциях, сопровождающихся геморрагической гипотензией (ГГ). Цель исследования - оценка в эксперименте динамики процессов СРО в тонкой кишке при геморрагической гипотензии на фоне применения анестетика севофлурана, обладающего эффектом анестетического прекондиционирования. Методика. Эксперименты проведены на 105 белых крысах-самцах. ГГ моделировали, используя в 1-й группе в качестве анестетика эфир во 2-й - анестетик севофлуран. Контролем служили 2 группы интактных животных: одна - с эфиром, другая - с севофлураном. Для оценки процессов СРО через 15 мин, 30 мин, 1 ч, 2 ч ГГ забирали фрагменты тонкой кишки. Исследование хемилюминесценции (ХЛ) гомогенатов тонкой кишки проводили по методу Р.Р. Фархутдинова, используя хемилюминомер “Флюорат АБЛФ-2Т”. Регистрировались показатели СРО: спонтанная светимость (СС), вспышка (В), светосумма (С∑). Результаты. Через 15 мин ГГ (2-я группа,. севофлуран) обнаружено повышение показателя СС в тощей кишке на 33%; снижение показателя В в 12-пк в 2 раза, в тощей и подвздошной кишке - на 24 и 36% соответственно. Показатель С∑ снижался в 12-пк на 36%, в тощей и подвздошной кишке - на 45% и 52% соответственно по сравнению с 1-й группой (эфир). На 30-й мин показатель СС в тощей кишке повышался на 80%. На фоне ГГ при применении севофлурана отмечено снижение показателя В в 12-пк на 38%, в тощей кишке на 22%, а в подвздошной в 3 раза. Через 1 ч ГГ при использовании севофлурана наблюдалось повышение СС в в тощей кишке в 2 раза, в 12-пк и подвздошной - на на 38% и 15% соответственно. Показатель В снижался в 12-пк на 67, в тощей - на 43%; Показатель С∑ в 12-пк и тощей кишке снижался в 2,6 и 2,5 раза, в подвздошной - на 70% по сравнению с группой «эфир». Через 2 ч ГГ в группе «севофлуран» обнаружено увеличение СС в тощей и подвздошной кишках на 80% и в 3 раза, соответственно, по сравнению с эфирным наркозом. При этом наблюдалось уменьшение С∑ в 12-п и тощей кишке - на на 24% и 15% соответственно. Заключение. На фоне ГГ наблюдается активация процессов СРО в тонкой кишке при использовании эфира; прекондиционирование анестетиком севофлураном способствовало значительному ограничению окислительного стресса в тонкой кишке крыс возможно за счет активации антиоксидантной системы. Introduction. The major pathogenetic factor of massive blood loss is hypoxia, which triggers activation of free-radical oxidation (FRO) processes in organs and tissues and the systemic inflammatory response. A universal factor of multiple organ dysfunction in blood loss is altered intestinal wall permeability with translocation of microflora and toxins into the systemic circulation during reperfusion. Recently, much of the attention has been focused on effects of anesthetic preconditioning, including during operations associated with hemorrhagic hypotension (HH). The aim of this study was to evaluate in experiment the dynamics of small intestinal FRO in HH during the use of the anesthetic sevoflurane, which has an effect of anesthetic preconditioning. Methods. Experiments were performed on 105 white male rats divided into two groups; groups 1 and 2 were exposed to HH with ether or sevoflurane as the anesthetic, respectively. Two groups of intact animals treated with ether or sevoflurane were used as the controls. Five animals died during the experiment. To evaluate FRO processes, samples of the duodenum, jejunum, and ileum were taken at 15 min, 30 min, 1 h, and 2 h of HH. The chemiluminescence (CL) study of small intestine homogenates was performed according to the Farukhutdinov method on a Fluorate ABLF-2T chemiluninometer. The following FRO indexes were recorded: spontaneous luminosity (SL), flash (F), and light sum (L∑). Significance of differences was determined with the Mann-Whitney test. Results. In the sevoflurane group 2 compared to the ether group after 15 min of HH, SL was increased in the jejunum by 33%; F was decreased in the duodenum by 50%, in the jejunum by 24%, and in the ileum by 36%; L∑ was decreased in the duodenum by 36%, in the jejunum by 45%, and in the ileum by 52%. At 30 min, SL in the jejunum was increased by 80%. In the HH+sevoflurane group, F was decreased in the duodenum by 38%, in the jejunum by 22%, and in the ileum by 27%; L∑ in the duodenum was decreased by 44%, in the jejunum by 45%, and in the ileum by 67%. After 1 h of HH+sevofluran, SL was increased in the jejunum twofold, in the duodenum by 38% and in the ileum by 15%; F was decreased in the duodenum by 67% and in the jejunum by 43%; L∑ in the duodenum was decreased by 62%, in the jejunum by 60%, and in the ileum by 70% compared to the ether group. After 2 h of HH+sevofluran, SL was increased in the jejunum and ileum by 80% and 67%, respectively, compared to the ether group. In this process, L∑ in the duodenum was decreased by 24% and in the jejunum by 15%. Conclusion. The HH+diethyl ether exposure was associated with activation of FRO processes in the small intestine. The sevoflurane preconditioning provided a significant restriction of oxidative stress in the rat small intestine due to activation of the antioxidant system in the duodenum, jejunum, and ileum at 1 h, 15 min, and 30 min of HH, respectively.

Low-Viscosity Ether-Functionalized Ionic Liquids as Solvents for the Enhancement of Lignocellulosic Biomass Dissolution

Due to the substantial usage of fossil fuels, the utilization of lignocellulosic biomass as renewable sources for fuels and chemical production has been widely explored. The dissolution of lignocellulosic biomass in proper solvents is vital prior to the extraction of its important constituents, and ionic liquids (ILs) have been found to be efficient solvents for biomass dissolution. However, the high viscosity of ILs limits the dissolution process. Therefore, with the aim to enhance the dissolution of lignocellulosic biomass, a series of new ether-functionalized ILs with low viscosity values were synthesized and characterized. Their properties, such as density, viscosity and thermal stability, were analyzed and discussed in comparison with a common commercial IL, namely 1-butyl-3-methylimidazolium chloride (BMIMCl). The presence of the ether group in the new ILs reduces the viscosity of the ILs to some appreciable extent in comparison to BMIMCl. 1-2(methoxyethyl)-3-methylimidazolium chloride (MOE-MImCl), which possesses the lowest viscosity value among the other ether-functionalized ILs, demonstrates an ability to be a powerful solvent in the application of biomass dissolution via the sonication method. In addition, an optimization study employing response surface methodology (RSM) was carried out in order to obtain the optimum conditions for maximum dissolution of biomass in the solvents. Results suggested that the maximum biomass dissolution can be achieved by using 3 weight% of initial biomass loading with 40% amplitude of sonication at 32.23 min of sonication period.

The conformational analyses of 2-amino-N-[2-(dimethylphenoxy)ethyl]propan-1-ol derivatives in different environments

Four crystal structures of 2-amino-N-(dimethylphenoxyethyl)propan-1-ol derivatives, characterized by X-ray diffraction analysis, are reported. The free base (R,S)-2-amino-N-[2-(2,3-dimethylphenoxy)ethyl]propan-1-ol, C13H21NO2, 1, crystallizes in the space group P21/n, with two independent molecules in the asymmetric unit. The hydrochloride, (S)-N-[2-(2,6-dimethylphenoxy)ethyl]-1-hydroxypropan-2-aminium chloride, C13H22NO2 +·Cl−, 2c, crystallizes in the space group P21, with one cation and one chloride anion in the asymmetric unit. The asymmetric unit of two salts of 2-picolinic acid, namely, (R,S)-N-[2-(2,3-dimethylphenoxy)ethyl]-1-hydroxypropan-2-aminium pyridine-2-carboxylate, C13H22NO2 +·C6H4NO2 −, 1p, and (R)-N-[2-(2,6-dimethylphenoxy)ethyl]-1-hydroxypropan-2-aminium pyridine-2-carboxylate, C13H22NO2 +·C6H4NO2 −, 2p, consists of one cation and one 2-picolinate anion. Salt 1p crystallizes in the triclinic centrosymmetric space group P\overline 1, while salt 2p crystallizes in the space group P41212. The conformations of the amine fragments are contrasted and that of 2p is found to have an unusual antiperiplanar arrangement about the ether group. The crystal packing of 1 and 2c is dominated by hydrogen-bonded chains, while the structures of the 2-picolinate salts have hydrogen-bonded rings as the major features. In both salts with 2-picolinic acid, the specific R 1 2(5) hydrogen-bonding motif is observed. Structural studies have been enriched by the generation of fingerprint plots derived from Hirshfeld surfaces.

Correlation between Functional Group and Formation of Nanoparticles in PEBAX/Ag Salt/Al Salt Complexes for Olefin Separation

poly ether-block-amide (PEBAX)-2533/metal salt/Al salt membranes were prepared for mixed olefin/paraffin separation. PEBAX-2533 with 80% ether group and 20% amide group was suggested as the polymer matrix for comparison of separation performance according to the functional group ratio in copolymer PEBAX. In addition, Al salts were used to stabilize metal ions for a long time as additives. High permeance was expected with the proportion of high ether groups, since these functional groups provided relatively permeable regions. As a result, the PEBAX-2533 composite membrane showed a selectivity of 5 (propylene/propane) with 10 GPU. However, the permeance of membrane was not unexpectedly improved and the selectivity was reduced. The result was analyzed by using SEM, RAMAN and thermogravimetric analysis (TGA), including Fourier transform infrared (FTIR). The reduction in separation performance was determined by using FT-IR. Based on these results, in order to stabilize the metal ions interacting with the polymer through Al(NO3)3, it was concluded that a specific ratio of the amide group was needed in PEBAX as a polymer matrix.

Correlation between Functional Group and Formation of Nanoparticles in PEBAX/Ag Salt/Al Salt Complexes for Olefin Separation

PEBAX-2533/metal salt/Al salt membranes were prepared for mixed olefin/paraffin separation. PEBAX-2533 with 80% ether group and 20% amide group was suggested as the polymer matrix for comparison of separation performance according to the functional group ratio in copolymer PEBAX. In addition, Al salts were used to stabilize metal ions for a long time as additives. High permeance was expected with the proportion of high ether groups since these functional groups provided relatively permeable regions. As a result, the PEBAX-2533 composite membrane showed a selectivity of 5 (propylene/propane) with 10 GPU. However, the permeance of membrane was not unexpectedly improved and the selectivity was reduced. The result was analyzed by SEM, FT-RAMAN and TGA, including FT-IR. The reduction in separation performance was determined by FT-IR. From these results, in order to stabilize the metal ions interacting with the polymer through Al(NO3)3, it was concluded that specific ratio of amide group was needed in PEBAX as polymer matrix.