Person: DİNCEL, DEMET
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Stachys thirkei C. Koch Bitkisinin Antikolinesteraz Potansiyelinin Araştırılması
An HPLC Method for the Determination of Saxagliptin in Human Plasma with Fluorescence Detection
Spectrophotometric Determination of Erdosteine at Capsule Dosage Forms
Abstract Objective: Two simple, rapid and sensitive methods were developed for determination of Erdosteine (ERD) in pure form as well as in their pharmaceutical formulations. Methods: The methods were based on formation of colored charge transfer complexes with ERD with chloranil (CA) and 7,7,8,8-tetracyanoquinodimethane (TCNQ). The obtained charge-transfer complexes were measured at 454 and 843 nm for CA and TCNQ methods, respectively. Optimization of different experimental conditions were investigated. Results: Beer's plots were obeyed in a general concentration range of 10-500 mu g mL(-1) and 20-600 mu g mL(-1) for CA and TCNQ methods, respectively. The validity of methods in terms of specificity, linearity, accuracy, precision, limit of detection and limit of quantitation were evaluated. Conclusion: The methods were applied successfully in the determination of ERD in capsule dosage forms. Developed new spectrophotometric methods have been found to be very practical and practical. The lack of complex sample preparation increases the applicability of the method.
Fatty acid content of Reseda lutea var. lutea with antioxidant potential.
ANALYTICAL METHODS FOR THE DETERMINATION OF POLYBROMINATED DIPHENYL ETHERS IN HUMAN MILK
Polybrominated diphenyl ethers (PBDEs), which are used as flame retardants, are widely used additives so many different kind of materials that are consumed by public. Current researches reveal a significant increase in the levels of PBDEs in human biological fluids all around the world. According to International Agency for Research on Cancer (IARC), PBDEs are declarated as carcinogenic agents and additionally a considerable risks have been shown in animal studies such as liver damage, alteration of thyroid hormone levels, neurotoxicity and hazardous effects on development of fetus. Due to the simplicity of human exposure routes such as ingestion, inhalation or dermal contact, it gains high importance to quantify PBDEs in biological fluids. The exposure to PBDEs is critic aspecially during pregnancy, fetus development and infancy. Excretion of PBDEs in human milk is the focus area for researchers in recent years.
Ent-kaurane diterpenoids isolated from Sideritis congesta
A new ent-kaurane diterpenoid, together with eight known ent-kauranes, were isolated from the petroleum ether and acetone extracts of the whole plant of Sideritis congesta P. H. Davis & Hub.-Mor. and their structures were elucidated as the new compound ent-7 alpha-acetoxy-16 beta, 18-dihydroxy-kaurane (7-acetyldistanol) (1) and the known compounds ent-3 beta,7 alpha-dihydroxy, 18-acetoxy-15 beta,16 beta-epoxykaurane (epoxyisolinearol) (2), sideroxol (3), sideridiol (4), siderol (5), 7-epicandicandiol (6), foliol (7), linearol (8) and sidol (9). Characterization of compounds 1-9 was based on spectral analyses and comparison with reported data, particularly the new compound 1 was identified by 1D- and 2D-NMR and mass spectroscopic analyses. The antioxidant potential of the extracts, and also of the ent-kauranes except for 7, was investigated by three methods including beta-carotene bleaching method, free radical scavenging activity and superoxide anion scavenging activity. The anticholinesterase activity was also evaluated for the ent-kauranes except for 7, and most of the diterpenes exhibited weak acetylcholinesterase inhibitory activity. However, almost all diterpenes exhibited some inhibitory activity against butyrylcholinesterase; particularly, compounds 3 and 6 exhibited better BChE inhibitory activity than the standard compound galanthamine. (C) 2011 Phytochemical Society of Europe. Published by Elsevier B. V. All rights reserved.