ABSTRACT
Methotrexate (MTX) is a folate antagonist drug used for several diseases, such as cancers, various ma-lignancies, rheumatoid arthritis (RA) and inflammatory bowel disease. Due to its structural features, including the presence of two carboxylic acid groups and its low native fluorescence, there are some challenges to develop analytical methods for its determination. MTX is metabolized to 7-hydroxymethotrexate (7-OH-MTX), 2,4-diamino-N10-methylpteroic acid (DAMPA), and the active MTX polyglutamates (MTXPGs) in the liver, intestine, and red blood cells (RBCs), respectively. Additionally, the drug has a narrow therapeutic range; hence, its therapeutic drug monitoring (TDM) is necessary to regulate the pharmacokinetics of the drug and to decrease the risk of toxicity. Due to environmental toxicity of MTX; its sensitive, fast and low cost determination in workplace environments is of great interest. A large number of methodologies including high performance liquid chromatography equipped with UV-visible, fluorescence, or electrochemical detection, liquid chromatography-mass spectroscopy, capillary electrophoresis, UV-visible spectrophotometry, and electrochemical methods have been developed for the quantitation of MTX and its metabolites in pharmaceutical, biological, and environ-mental samples. This paper will attempt to review several published methodologies and the instru-mental conditions, which have been applied to measure MTX and its metabolites within the last decade.
ABSTRACT
In the present study, the effects of hypo-osmotic and hyper-osmotic shock on β-carotene and glycerol production by a native strain of Dunaliella salina isolated from Maharlu Salt Lake, Fars province, Iran, were investigated. The amount of β-carotene and glycerol at 1 h, 2 h, 8 h and 24 h after initiating hypo-osmotic (1 M NaCl) and hyper-osmotic shocks (3 M NaCl); and at normal condition (2 M NaCl) were measured. At hyper-osmotic medium, β-carotene concentration reached to maximum amount after 2 h and remained constant up to 24 h. Even so, increasing of glycerol concentration was initiated after 2 h and reached the highest value at 24 h after salinity stress induction. At hypo-osmotic shock, β-carotene and glycerol concentrations were decreased. There are lots of lakes and salt marshes in Iran, which can be suitable environments for growing D. salina. So it seems that the isolated D. salina is potentially useful for planting in small locations to promote the commercial production of β-carotene and glycerol.