Antibiotics are commonly used to control, treat, or prevent bacterial infections, however bacterial resistance to all known classes of traditional antibiotics has greatly increased in the past years especially in hospitals rendering certain therapies ineffective. To limit this emerging public health problem, there is a need to develop non-incursive, non-toxic, and new antimicrobial techniques that act more effectively and quicker than the current antibiotics. One of these effective techniques is antibacterial photodynamic therapy (aPDT). This review focuses on the application of porphyrins in the photo-inactivation of bacteria. Mechanisms of bacterial resistance and some of the current ‘greener’ methods of synthesis of meso-phenyl porphyrins are discussed. In addition, significance and limitations of aPDT are also discussed. Furthermore, we also elaborate on the current clinical applications and the future perspectives and directions of this non-antibiotic therapeutic strategy in combating infectious diseases.
This study was carried out to determine the pH and levels of caffeine in eight brands of carbonated and energy drinks available in local market in Yenagoa, Nigeria. Quantitative analysis of caffeine was performed by a simple and fast standard UV spectrophotometric method, using carbon tetrachloride as the extracting solvent. Results showed that the pH of the beverages were slightly acidic ranging from 5.92-6.44. The minimum caffeine level was observed in the carbonated soft drink Coca Cola (43.71±0.55 ppm), while the energy drink, Red Bull sample showed the highest caffeine content (58.31±0.35 ppm). The carbonated soft drinks showed caffeine levels in the range of 43.71 and 45.83 ppm with average concentration of 44.52 ppm, whereas in the energy drinks it ranged from 47.56 to 58.31 ppm with a mean concentration of 52.24 ppm. The caffeine content in all the beverage samples analyzed in this study are well below the maximum allowable limits set by the US Food and Drugs Administration.
This study investigated the anti-diabetic activity of the root bark extract of Parquetina nigrescens and the isolated compound, convallatoxin, from the root bark. A powdered sample of the plant was extracted with methanol, and the extract (A) was tested in glucose-loaded normal rats at 100, 200 and 400 mg/kg for the determination of the most active dose. The anti-diabetic activity of A at 200 mg/kg was carried out on streptozotocin-induced diabetic rats. A was further partitioned to obtain its n-hexane (B 1 ), dichloromethane (B 2 ), ethyl acetate (B 3 ) and mother liquor (B 4 ) fractions that were tested for blood glucose lowering activity using glucose-loaded normal rats model. The anti-
Polyethylene Glycol Monoalkyl Ethers, C x H 2x+1 (OC 2 H 4 ) n OH, (PEGMAE), are polar compounds like Polyethylene Glycols (PEG) and they undergo microbial degradation which produces toxic substances that are potentially dangerous to the environment. Therefore, the purpose of this study is to carry out proper identification and characterization of these compounds. The Electron Ionization (EI) and Chemical Ionization (CI) spectra of various PEGMAE were obtained by Gas Chromatography/Mass Spectrometry (GC/MS) and were used to identify and characterize these compounds. The characteristic cleavages in the EI and CI reactions of PEGMAEs were also studied. The results obtained showed that the methane CI mass spectra of the PEGMAE contain MH + ions and fragment ions similar to those found in their EI mass spectra. The relative abundances of the MH + ions are low, variable and increase with increasing sample size across the chromatographic peaks; but do not increase with increasing x or n. The base peaks of the low mass oligomers (x≤3) are PEG related (e.g., m/z 45, 59) but those of higher mass oligomers (x≥4) include the ion at m/z 63 (HOC 2 H 4 OH) H + or m/z 107 (HO (C 2 H 4 O) 2 H) H + . There are no (MH-H 2 O) + ions or protonated dimer ions (n≥2, x≥2) in the spectra of PEGMAE. The Relative Molar Sensitivities (RMS) or the Relative Sensitivity per Gram (RSG) increases linearly with molecular polarizabilty or molecular weight with a non-zero intercept.
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