Polymeric micellar systems are emerging as a very important class of nanopharmaceuticals due to their ability to improve pharmacokinetics and biodistribution of chemotherapy drugs, as well as to reduce related systemic toxicities. While these nanosized delivery systems inherently benefit from passive targeting through the enhanced permeation and retention effect leading to increased accumulation in the tumor, additional active targeting can be achieved through surface modification of micelles with targeting groups specific for overexpressed receptors of tumor cells. In this project, nontoxic, biodegradable, and modularly tunable micellar delivery systems were generated using two types of dendron-polymer conjugates. Either an AB type dendron-polymer construct with 2K PEG or an ABA type dendron-polymer-dendron conjugate with 6K PEG based middle block was used as primary construct; along with an AB type dendron-polymer containing a cRGDfK targeting group to actively target cancer cells overexpressing αβ/αβ integrins. A set of micelles encapsulating docetaxel, a widely employed chemotherapy drug, were prepared with varying feed ratios of primary construct and targeting group containing secondary construct. Critical micelle concentrations of all micellar systems were in the range of 10 M. DLS measurements indicated hydrodynamic size distributions varying between 170 to 200 nm. An increase in docetaxel release at acidic pH was observed for all micelles. Enhanced cellular internalization of Nile red doped micelles by MDA-MB-231 human breast cancer cells suggested that the most efficient uptake was observed with targeted micelles. In vitro cytotoxicity experiments on MDA-MB-231 breast cancer and A549 lung carcinoma cell lines showed improved toxicity for RGD containing micelles. For A549 cell line EC values of drug loaded micellar sets were in the range of 10 M whereas EC value of free docetaxel was around 10 M. For MDA-MB-231 cell line EC value of free docetaxel was 6 × 10 M similar to EC of nontargeted AB type docetaxel doped micellar constructs whereas the EC value of its targeted counterpart decreased to 5.5 × 10 M. Overall, in this comparative study, the targeting group containing micellar construct fabricated with a 2 kDa PEG based diblock dendron-polymer conjugate emerges as an attractive drug delivery vehicle due to the ease of synthesis, high stability of the micelles, and efficient targeting.
Two flavonoid glycosides (compounds 1 and 3) of which one is reported for the first time and a methylinositol (compound 2) were isolated from the aerial parts of Ebenus haussknechtii (Leguminosae). The structures were established as quercetin-7-O-[alpha-L-rhamnopyranosyl(1 --> 6)-beta-D-galactopyranoside] (1), morin-3-O-[4-[5-(4-hydroxyphenyl)pentanoyl]-alpha-L-rhamnopyranosyl(1 --> 6)-beta-D-galactopyranosyl]-7-4'-di-O-methyleter (3), and methylinositol (2) on the basis of chemical and spectroscopic means. The antimicrobial activities of the extracts have also been examined.
The number of known lichen species is about 18.000. Some of their metabolic products appear only in lichens, while others are also present in higher plants and fungi. Their secondary metabolites play a dominant role in their system [1,2]. Lichens have long been used for commercial purposes such as alcohol production and in the perfume, dye, and drug industries, and as food [3,4]. About 60 lichen species are present in different types of antimicrobial, anticancer, antiallergen, immunogical, and expectoral drugs [5][6][7][8][9]. Previous reports on many lichen species have been used to measure air pollution by detecting SO 2 and heavy and radioactive metals. The role of photoactive lichen substances in photosynthesis has been examined in environmental pollution [10,11]. Many scientists have been studying the carbohydrate composition of lichens. β-D-Glucans, which are linked to polyols, are also important in medicine because of their antitumor activities [5,12]. Many microbiological activity studies of some lichens explain the activities on gram (+) and gram (-) bacteria and fungi [13][14][15]. Two studies on Turkish lichens explain the isolation and structural determination of some natural products and their fluorescence emission properties, and some of them describe the volatile compounds of some lichens [16,17]. In the present study, the chemical composition of apolar phases of the above lichens was reported by a gas chromatography-mass spectrometry (GC-MS) combined system, and the results were examined in terms of EFAs and their importance for a healthy diet. In addition to this, volatile compounds were detected for the first time from E. prunastri and L. vulpina.The nineteen known apolar compounds of P. furfuracea, E. prunastri, and L. vulpina are given in Table 1. Besides these, 2-hydroxy-4-methoxy-3,6-dimethylbenzoic acid was isolated for the first time from P. furfuracea. In Table 1, the given compounds are known except cis-4b, 5,9,10-tetrahydro-8-methoxy-5-methylindenol [1,2-b] indole from E. prunastri. This compound was detected for the first time from this lichen species. Detected compounds and their percentages for L. vulpina are given in Table 1. The compound 1,2-benzenedicarboxylic acid bis (2-ethylhexyl) ester [bis(2-ethylhexyl) phthalate] was found for the first time from this material. The GC-MS results showed that the linoleic acid (LA) and α-linolenic acid (ALA) percentages were much higher than for other compounds in these studied lichen species. The percentages of them are also much greater than for higher plants.It is known that some kinds of polyunsaturated fatty acids (PUFA) cannot be synthesized by mammalian cells, and therefore they have to be provided by diet [18]. The intakes of EFAs (LA and ALA) must balance each other. The desirable intake quantities of these two chemicals have been reported as 10.04 and 1.55 grams a day in terms of LA and ALA amounts. The recommended required daily minimum intake ratio of LA to ALA leading to a substantial health change is about 6:1 [18]. The mediterr...
The hexane extracts of eight Cephalaria (Dipsacaceae) species, which were collected from southwestern Anatolia, were obtained by Soxhlet apparatus. The fatty acids were derived to methyl esters and determined by gas chromatography/flame ionization detector (GC/FID) and gas chromatography/mass spectrometry (GC/MS) systems. The dominant fatty acid components and maximum percentages were detected as myristic [in C. joppica (17.48 %)], palmitic [in C. cilicica, C. elmaliensis, C. isaurica, C. scoparia (19.51 %), and C. gazipashaensis], linoleic [in C. joppica (33.02 %), C. elmaliensis, C. dipsacoides, and C. gazipashaensis], α-linolenic (ALA) [in C. cilicica, C. elmaliensis, C. isaurica, C. scoparia, C. lycica, and C. gazipashaensis (47.95 %)] and oleic [in C. isaurica and C. dipsacoides (40.66 %)] acids. The antioxidant activity of all hexane extracts was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferric thiocyanate (FTC), and thiobarbituric acid (TBA) methods. The results indicate that hexane extracts of Cephalaria species possess considerable antioxidant activity. The highest radical scavenging activity was detected in C. isaurica (IC50 = 741 μg/mL). The most effective species on lipid peroxidation are C. lycica and C. gazipashaensis in FTC and TBA assays, respectively. This study reveals that Cephalaria species are attractive sources of fatty acid components, especially the essential ones, as well as of effective natural antioxidants.
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