Razieh Sadat Solouki Nezhad, Hanieh Asaadi, Yaser Eshaghi Milasi, Sajjad Yazdansetad,
Volume 6, Issue 1 (5-2019)
Abstract
The production of pigments from bacteria is significant due to the low cost, high yield and ease of extract compared with other sources. Carotenoids are one of the most important pigments with antioxidant properties which are the precursor of vitamin A synthesis and have antibody overproduction ability, anti-tumor activity and inhibitory effect on the cardiovascular disease. The present study aimed to isolate and identify carotenoid-producing bacteria by high-performance liquid chromatography (HPLC) analysis of their carotenoid pigments. Twenty soil samples were collected from different regions of Tehran. After serial dilution each sample was cultured on BHI agar medium and incubated at 37°C. The pigment-producing bacteria were selected for further identification and their pigments were extracted by methanol. The screening was carried out at two levels: i) selection of the strains by visual color inspection, ii) analysis of the pigment extracts by UV-VIS spectroscopy and HPLC. The isolates were identified by phenotypic methods and their 16S rDNA gene was amplified by PCR method and sequenced. Staphylococcus epidermidis, Micrococcus aloeverae, Citricoccus alkalitolerans, Rhodococcus zopfii, Arthrobacter agilis, Dietzia natronolimnaea and Rhodococcus ruber were identified as carotenoid-producing strains. The highest rate of absorption was observed using UV-VIS analysis in Staphylococcus epidermidis and Dietzia natronolimnaea. The comparison of HPLC analysis with the standard β-carotene curve showed that the carotenoids were beta-carotene. Micro-organisms are a potential source in the production of pigments. In this study we introduced two genera of bacteria (Staphylococcus epidermidis and Dietzia natronolimnaea) with carotenoid-producing ability.
Golnaz Parvizi Fard, Lale Solouki, Mostafa Zakariazadeh, Hossein Haghaei, Somaieh Soltani,
Volume 9, Issue 3 (12-2022)
Abstract
Human serum albumin is one of the most important blood proteins that has the ability to bind a wide range of compounds and different drugs. Hence, knowing how drugs bind to albumin is crucial to understand their pharmacokinetics and pharmacodynamic properties. The binding of drugs to protein affects the drug's excretion, distribution and interaction in the target tissues. Nicotinamide (NA) is a safe and inexpensive medical supplement that used to prevent and treat vitamin B3 deficiency. In this research, the molecular mechanism of the interaction between nicotinamide and human serum albumin was studied by the utilization of spectroscopic and molecular docking methods. The effects of temperature, acidic/basic pHs, metal ions, urea, and glucose on the interaction between nicotinamide and human serum albumin were also investigated. The spectroscopic studies indicated that the interaction between nicotinamide and human serum albumin is mainly controled by hydrophobic forces and the interaction is spontaneous. The number of binding site and binding constant is 1 and 4.6×104 (L/mol), respectively, which were increased in the presence of glucose. The presence of metallic ions and basic pH decreased the binding constant of nicotinamide to albumin. The obtained results indicated that nicotinamide tend to binds to the similar sites wherever the molecules with acidic moieties bind. The results could be helpful to interpret the mechanisms of actions of nicotinamide in the various physiological phenomena in the human body.
