Solid lipid nanoparticles (SLN) for controlled drug delivery - a review of the state of the art.

Flora of Turkey and the East Aegean Islands.

Solid lipid nanoparticles for parenteral drug delivery.

A list of 1719 chemical compounds identified from headspace samples of floral scent is presented. The list has been compiled from some 270 published papers, including analyses of 991 species of flowering plants and a few gymnosperms, a sample including seed plants from 90 families and 38 orders. The compounds belong to seven major compound classes, of which the aliphatics, the benzenoids and phenylpropanoids, and, among the terpenes, the mono- and sesquiterpenes, occur in most orders of seeds plants. C5-branched compounds, irregular terpenes, nitrogen-containing compounds, and a class of miscellaneous cyclic compounds have been recorded in about two-thirds of the orders. Sulfur-containing compounds occur in a third of the orders, whereas diterpenes have been reported from three orders only. The most common single compounds in floral scent are the monoterpenes limonene, (E)-β-ocimene, myrcene, linalool, α- and β-pinene, and the benzenoids benzaldehyde, methyl 2-hydroxybenzoate (methyl salicylate), benzyl alcohol, and 2-phenyl ethanol, which occur in 54–71% of the families investigated so far. The sesquiterpene caryophyllene and the irregular terpene 6-methyl-5-hepten-2-one are also common and occur in more than 50% of the families. Orchidaceae are by far the best investigated family, followed by several families known to have many species with strongly scented flowers, such as Araceae, Arecaceae, Magnoliaceae, and Rosaceae. However, the majority of angiosperm families are still poorly investigated. Relationships between floral scent and pollination, chemistry, evolution, and phylogeny are briefly discussed. It is concluded that floral scent chemistry is of little use for phylogenetic estimates above the genus level, whereas the distribution and combinations of floral scent compounds at species and subspecific levels is a promising field of investigation for the understanding of adaptations and evolutionary processes in angiosperms.

/pdf/diversity-and-distribution-of-floral-scent-3kpxfsqrud.pdf

Diversity and Distribution of Floral Scent

The generation of reactive oxygen radicals in mammalian cells profoundly affects numerous critical cellular functions, and the absence of efficient cellular detoxification mechanisms which remove these radicals can result in several human diseases. Growing evidence suggests that reactive oxygen species (ROS) within cells act as second messengers in intracellular signaling cascades which induce and maintain the oncogenic phenotype of cancer cells. ROS are tumorigenic by virtue of their ability to increase cell proliferation, survival, cellular migration, and also by inducing DNA damage leading to genetic lesions that initiate tumorigenicity and sustain subsequent tumor progression. However, it is also known that ROS can induce cellular senescence and cell death and can therefore function as anti-tumorigenic agents. Therefore, the mechanisms by which cells respond to reactive oxygen species depends on the molecular background of cell and tissues, the location of ROS production and the concentration of individual ROS species. Carcinoma cells produce ROS at elevated rates in vitro, and in vivo many tumors appear persistent to oxidative stress. Thus, the finding that a diet rich in antioxidants or the elimination of ROS by antioxidant compounds prevents the development of certain cancers provided the setting for subsequent investigation of the tumorigenic actions of reactive oxygen species. This review outlines the current knowledge on the various roles of ROS in tumor development and progression.

Reactive oxygen species in tumor progression.

This study was conducted to evaluate the suitability of using hexagonal boron nitride (hBN) as reinforcement in natural fibres obtained from hazelnut shell (F) and poppy straw (H). Raw materials were treated with alkali to enrich the cellulose content by removing lignin and hemicellulose. The nanobiocomposite synthesis was performed with 4% and 8% of hBN. Lignin, cellulose and hemicelluloses contents of biomass were determined. Cellulose content was almost increased 3-fold and 2-fold after pretreatment of hazelnut shell (FCell) and poppy straw (HCell), respectively. Strong bands at 812 and 1380cm-1 corresponding to hBN were observed in the FTIR. SEM images showed that hBN is retained on the pretreated natural fibres. Adsorbed hBN on the structure was highest in the microcrystalline cellulose (Cell) (91.5%), followed by FCell (80.5%) and HCell (50.5%). Nanobiocomposites containing lignocellulose and hBN may be recommended for use in polymer matrix structures where thermal properties need to be altered.

https://dergipark.org.tr/tr/download/article-file/502070

The nanobiocomposites synthesis from biomass and its characterization

Chitosan beads were prepared as a support material for immobilization of pectinases using a sequential layering approach. Glutaraldehyde (GA) was used as an activating agent for covalent binding. Different concentrations of cross-linking agent were examined and the highest specific activity of 7.8 U/mg was observed at 3% GA concentration, which was used in the multilayered immobilization studies. Three layers of pectinases were covalently immobilized on the support. As the layer number increased the total bound protein content and the activity of the chitosan beads increased; however, their specific activity significantly decreased from 9.1 U/mg in the first layer to 2.9 U/mg in the 3-layered structure. The results suggested that increasing the density of pectinases on chitosan support might have decreased the catalytic ability of enzymes due to either restriction to the protein backbone or due to substrate accessibility limitations. Therefore, optimal protein loading should be pursued for utilization of immobilized pectinases with highest specific activity. Keywords : Enzyme Immobilization, Pectinase, Chitosan Support, Glutaraldehyde

/pdf/immobilization-of-pectinases-by-sequential-layering-on-3uua9lc4kf.pdf

Berrin Bozan

Papers

The nanobiocomposites synthesis from biomass and its characterization

Immobilization of Pectinases by Sequential Layering on Chitosan Beads