فهرست مطالب maryam khayati

Three species of Tripleurospermum Sch. Bip., are reported for the first time for the flora of Iran, including T. conoclinium (Boiss. & Balansa) Hayek from Ardabil province in North West Iran, T. rosellum var. album (Boiss. & Orph.) Hayek and T. callosum (Boiss. & Heldr.) E. Hossain from West Azarbayejan province. The micromorphology of fruit of these species have also been investigated by SEM. Furthermore, geographical distribution of the new records is discussed.

In this study, a green and efficient method for the synthesis of biologically-active bis(indolyl)methane compounds (BIMs) has been described through the condensation of indole with different carbonyl compounds in the presence of SO3H-functionalized mesoporous silica materials (MCM-41-SO3H) catalyst under ball milling. Synthesis of BIMs is proceed very well in the presence of nano-ordered MCM-41-SO3H under solvent-free conditions using ball-milling technique at room temperature. The MCM-41-SO3H can be used at least four consecutive times under optimized conditions with a slight decrease in its catalytic activity. High to quantitative yields of the desired products, low loading of the catalyst, short reaction times at ambient temperature, reusability of the catalysts, and avoiding the use of toxic solvents are significant advantages of this green protocol.

Organophosphorus (OP) forms an important class of toxic compounds. They inhibit acetyl cholinesterase (AChE, EC 3.1.1.7) that results in respiratory and myocardial malfunctions. Pesticides could be accumulated in vegetables and fruits, so detection of them is very important. The goals of this study are decreasing detection time and detection limit of methyl parathion bioprobe. In this research the methyl parathion bioprobe based on modified glassy carbon (GC) electrode-immobilized AChE is constructed. β-cyclodexterin (β-CD)/chitosan-multiwall carbon nanotube (CS-MCNT) composite, first by polymer wrapping method and then by layer-by-layer self-assembly technique, was prepared. Then different combination of β-CD, CS-MCNT and graphene was deposited on GC electrode. AChE solution (4mg/ml) was deposited on the modified GC electrode and dried in air at room temperature. The electrochemical measurement is based on AChE inhibition by methyl parathion (MPT) in the presence of acetyl choline iodide (ACTI) as substrate with cyclic voltammetry method. The results show that using graphene contributes to considerable increasing in current up to 27 µA. These measurements were done in phosphate buffer (pH = 7.5) and at 25°C. In another part the optimum pH and temperature were measured that were 7.5 and 55°C receptively. Detection limit for MPT was gained 5nM.

Proteases are important enzymes that their role in various industries is undeniable. However, keeping enzymes stable during its activity in harsh conditions is so important. In this study, protease enzyme was immobilized on the porous silica particles and its stability in different temperatures and pHs was evaluated. First silica particles were aminated by 3-aminopropyltriethoxysilane then the protease enzyme was immobilized on the modified silica by glutaraldehyde cross-linking method and the immobilized enzyme’s activity was maintained for more than 40 days. Measuring the free subtilisin carlsberg enzyme activity and immobilized enzyme was performed according to the Lowry method. In another part, the effects of different pHs and temperatures on free and immobilized protease were evaluated. The immobilized protease activity was measured in temperature range between 25-75◦C and pH range 6.5-12. The absorption was read in 660nm. It is shown that the optimum temperature for immobilizaed enzyme is 50°C. The results showed that immobilized protease is more stable than free protease.

Tripleurospermum transcaucasicum (Manden.) Pobed (Asteraceae, Anthemideae) is newly recorded from East Azarbayejan Provice, NW Iran. It is morphologically similar to T. caucasicum (Willd.) Hayek and T. monticolum (Boiss. & A.Huet) Bornm. The morphological and anatomical diagnostic characters of new record are compared with closely related species. The geographical distribution of new records and related species in Iran are presented.

Bacteriorhodopsin (BR) is a retinal protein that is a light-driven proton pump and has an important role in photosynthesis in archaebacterium Halobacterium salinarum. The BR molecule absorbs light and photochemical changes occur in it, and different intermediates will be produced in its photochemical cycle that some of them like P and Q intermediates have a long half-life. There have been many efforts to immobilize BR for constructing data storage devices. In this study the BR suspension-contained film has been immobilized on a polycarbonate and the effects of green and red lasers on it (in different times and temperatures) have been investigated by UV spectrophotometer method, The modified surfaces were characterized by ATR-FTIR and AFM techniques. The results show that with used condition for immobilization of BR on polycarbonate, the 0 and 1 bite that relate to BR and P, Q intermediate, are formed. The red and green lasers convert BR to O and, P or Q intermediates respectively that could be used instead of 0 and 1 bites in popular compact disks.

The Protease enzyme breaks down protein into amino acids as its constructors. Protease immobilization onto appropriate support materials plays an essential role in various fields of technology including the food and detergent industries. Accordingly, improvement of protease immobilization has been highly regarded due to its applications in bio catalysis. Alginate and chitosan are natural polysaccharides that have been studied so extensively in enzyme immobilization.In this research, the physical immobilization of proteases in alginate-chitosan beads showed satisfactory activity and stability. These beads were prepared by adding protease-alginate dropping intoChitosan­ and Calcium chloride solution. Then proteases enzyme encapsulated in alginate-chitosan beads. In the end, the different conditions such as temperature, pH and stability of the enzyme were studied. The immobilized protease was optimized in temperature of 47°C and at pH 8.5. The results demonstrated that the protease enzyme immobilized in alginate-chitosan beads exhibits reasonable stability and good activity.

This study includes 4 reports of chromosome counts in Tripleurospermum Sch. Bip. belonging to the tribe Anthemideae of the family Asteraceae from Iran. Confirming the reported base number of x=9 for this genus، the species studied include diploid and tetraploid species. Chromosome counts for three species are reported for the first time from Iran.