Performance comparison of chlorinated chiral stationary phases in supercritical fluid chromatography for separation of selected pyrrolidone derivatives / 药物分析学报

The effects of two chlorinated chiral stationary phases, namely, Lux Cellulose-2 and Lux i-Cellulose-5, flow-rate, percentage of co-solvent and chemical structures of the compounds on retention and reso-lution were studied within this article. In this work a backpressure of 150 bar, a temperature of 40 ℃ and 10％ of methanol as co-solvent were chosen as operating conditions. The optimum flow-rate was 2 mL/min. The percentage of co-solvent was studied between 7.5％ and 15％. We have observed that 15％ of methanol gave the best results for most of the compounds. For all the derivatives, the Lux Cellulose-2 provided better resolutions going from 1.50 to 3.59 compared with Lux i-Cellulose-5.

Identification and partial purification of antibacterial compounds against Streptococcus mutans from Galla Rhois / 대한구강보건학회지

OBJECTIVES: This study aims to identify and partially purify antibacterial compounds against Streptococcus mutans from Galla Rhois extract. METHODS: Galla Rhois was extracted with n-hexane or ethanol and concentrated in a rotary evaporator. The antibacterial effect of the Galla Rhois extract against S. mutans was determined by the paper discdiffusion method with n-hexane, ethanol, methanol, ethyl acetate, dimethyl sulfoxide (DMSO), acetone, and distilled water as the solvents. The active compounds were purified by partition chromatography, thin-layer chromatography (TLC), and high-performance liquid chromatography (HPLC). RESULTS: The antibacterial effect of the n-hexane extract was more effective against S. mutans than the ethanol extract (P<0.05). The antibacterial component of Galla Rhois was partially purified using partition chromatography and HPLC, and the antibacterial activity was confirmed. CONCLUSIONS: The partially purified component of Galla Rhois showed strong antibacterial effect against S. mutans. These results confirm that the antibacterial compounds of Galla Rhois can be used for the prevention of dental caries.

Antibacterial effect of Herniaria hirsuta, Prunus avium, Rubia tinctorum and Sempervivum tectorum plant extracts on multiple antibiotic resistant Escherichia coli / Efeito antibacteriano de Herniaria hirsuta, Prunus avium, Rubia tinctorum e Sempervivum tectorum extratos vegetais em vários resistentes a antibióticos Escherichia coli

The emergence of Escherichia coli isolates with multiple antibiotic resistant phenotypes is considered as a severe health concern. In the present work the antibacterial effect of following plants (Herniaria hirsuta, Prunus avium, Rubia tinctorum and Sempervivum tectorum) was examined. The bacterial model used for estimation of bacterial susceptibility is hospital multiple antibiotic resistant E. coli strain. E. coli ATCC 25922 was used for standard comparison of bacterial susceptibility. Leaves of H. hirsuta, R. tinctorum and S. tectorum as well as petioles of P. avium were collected. Ethanol and aqueous extract of each plant was prepared. Antibacterial activity was examined using the agar well diffusion method. Concentration of total phenols, flavonoids, tannins, antocyanins and saponins was determined in plant extracts. E. coli strain is resistant to four unrelated families of antibiotics. Antibacterial effect is proven for all examined plants. Ethanol extracts of H. hirsuta and P. avium have a more potent antibacterial effect than their aqueous extracts. Aqueous extracts of R. tinctorum and S. tectorum have higher antibacterial potential than theirs ethanol extracts. Examined plant extracts represent good candidates for more extensive research in view of their application in the treatment of multiple antibiotic resistant E.coli strains.

O surgimento de Escherichia coli isoladas com vários fenótipos resistentes aos antibióticos é considerado como um grave problema de saúde. No presente trabalho o efeito antibacteriano das seguintes plantas (Herniaria hirsuta, Prunus avium, Rubia tinctorum e Sempervivum tectorum) foi analisado. O agente bacteriano modelo utilizado para estimativa de susceptibilidade bacteriana é o hospital vários resistentes a antibióticos E. coli. E. coli ATCC 25922 padrão foi utilizado para comparação de antibiogramas. Folhas de H. hirsuta, R. tinctorum e S. tectorum bem como pecíolos de P. avium foram coletados. Etanol e extrato aquoso de cada planta foi preparado. Atividade antibacteriana foi analisada através do método de difusão em ágar-bem. Total Concentração de fenóis, flavonóides, taninos e saponinas antocyanins determinou-se em extratos de plantas. E. coli estirpe é resistente às quatro famílias de antibióticos independentes. Efeito antibacteriano é comprovado para todas as plantas examinadas. Os extratos etanólicos de H. hirsuta e P. avium têm um efeito mais potente antibacteriano de seus extratos aquosos. Extratos aquosos de R. tinctorum e S. tectorum têm maior potencial antibacteriano que os extratos etanólicos. Extratos vegetais examinados representam bons candidatos para pesquisa mais ampla em vista de sua aplicação no tratamento de vários antibióticos resistentes a cepas de E. coli.

Investigation of Nutrient Content, Phytochemical Content, Antioxidant Activity and Antibacterial Activity of Inedible Portion of Pomegranate (Punica granatum L.).

Pomegranate is a plant with high potential to have antimicrobial and antioxidant compounds. In the present study inedible parts (peel and seed) of pomegranate, variety “Bhagawa” were examined for the presence of phytochemicals, phenolic compounds, flavonoids, anthocyanin, antioxidant and anti-microbial compounds. Further, nutrition value of the samples was also examined. Results of GC-MS analysis carried out using four different solvents showed 12 and 25 fractions for peel and seed extracts respectively. Both peel and seed were with high amount of Anthocyanin, Phenolic compounds and Flavonoids. Both extracts gave 100% free radicals reduction in DPPH assay showing high antioxidant activity. Further, both extracts showed antibacterial activity against eight tested food borne pathogens. Antibacterial activity shown by peel extracts was higher than that of seed extract. Both peel and seed extracts showed highest and lowest antibacterial activity against Staphylococcus aureus and Listeria monocyatogenes respectively. Both extract showed same antibacterial activity which was shown by Kanamycin for Shigella fexneri. According to the present study, pomegranate peel and seed can be used to extract antibacterial, antioxidant compounds and flavonoids for the use in food industry.

In vitro AFM evaluation of Streptococcus mutans membrane exposed to two mouthwashes.

Streptococcus mutans is the primary microorganism of the dental plaque, which causes the caries disease. In addition to tooth brushing, oral care products are usually recommended by dentists to reduce and prevent the plaque formation. The objective of this work was to assess via atomic force microscopy the Streptococcus mutans membrane exposed to two mouthwashes, one containing triclosan, and the other, phenolic essential oils. S. mutans were cultured in brain and heart infusion during 48 hours at 37C. The pellets were harvested by centrifugation (2500 rpm, 3 min), and re-suspended in 4 mL mouthwash. One minute later, the bacterial cells were washed twice times by centrifugation (2500 rpm, 3 min) using saline solution (0.9% NaCl). The cell mass was gently spread over clean glass coverslip and evaluated by atomic force microscopy, in dynamic mode. For microorganisms not exposed to mouthwashes, images showed clustered microcolonies with round-shaped cells in typical string arrangement. Measured mean diameter varied between 0.6 μm and 1.0 μm. Exposure to phenolic essential oils caused no perceptible alterations in the bacterial cells. However, after exposure to triclosan, cell membranes were slightly wrinkled, probably due to the structural perturbations caused in the membrane permeability.

Isolation and characterization of actinomycetes from soil and evaluation of antibacterial activities of actinomycetes against pathogens.

Actinomycetes are one of the most attractive sources of antibiotics. In the present studies, total of 15 strains were isolated from Dr. Ram Manohar Lohia Hospital and RML Park in Lucknow, U.P India. Isolated strains were identified for their antibacterial activity but only six isolate showed good result, they were evaluated for their inhibitory activity on 3 strains of microorganism (E. coli, P. aeruginosa and S. aureus). Isolation of Actinomycetes strain was obtained by serial dilution method and grown on actinomycetes isolation agar. Antibacterial compounds were produced by submerged fermentation and activity of compounds were checked against bacterial culture by antibiogram analysis where intracellular and extracellular compounds showed positive result, compare to intracellular compounds, extracellular compounds was showing best result which was 30 mm zone of inhibition against S. aureus and MIC was found to be 0.0009 mg/ml.