Search

Randomly ordered mesoporous silicas hollow microspheres of 20-50 μm in diameter with distinguished characteristic of interconnected porosity (7-14 nm) of their thin outer walls are developed. Food grade emulsifier polyglycerol esters of fatty acids (PGEFA) are used as a soft-template and n-decane as a swelling agent, which was necessary for the formation of silica doped micelles to improve the mesoporous channel orientation without leading the phase transition. The interconnected pore channels that extend from the outside of the microspheres shell to its inside are used to fill the mesoporous silicas microspheres for enhanced encapsulation of VB3 precursor and cumulative in vitro release of vitamin B3 with considerable rate pharmacokinetics using simple pH trigger mechanism for the delivery systems. Refereed/Peer-reviewed

The adsorption of linear tetrapyrroles and porphyrins to mesoporous silicas with pore diameters of 2.3, 2.7, 4.0, and 7.0 nm from a benzene solution was investigated. As linear tetrapyrroles, 1,15,21,22-tetrahydro-19-benzoyl-5,10,15-triphenyl-15-hydroxybilin-1-one (biladien- ab -one, 1a ), its zinc complexes ( 2 and 3 ), 1,15,21,22-tetrahydro-19-(4-hexyloxybenzoyl)-5,10,15-tri(4-hexyloxy)phenyl-15-hydroxybilin-1-one (C6-biladienone, 1b ), 1,15,21,22-tetrahydro-19-(4-nonyloxybenzoyl)-5,10,15-tri(4-nonyloxy)phenyl-15-hydroxybilin-1-one (C9-biladienone, 1c ), 1,15, 21,22-tetrahydro-19-(4-dodecyloxybenzoyl)-5,10,15-tri(4-dodecyloxy)phenyl-15-hydroxybilin-1-one (C12-biladienone, 1d ), and 1,15,21,22-tetrahydro-19-(3,5-didodecyloxybenzoyl)-5,10,15-tri(3, 5-di-dodecyloxy)phenyl-15-hydroxybilin-1-one ( 1e ) were employed. As porphyrins, 5,10,15,20-tetraphenylporphyrin ( 4a ) and 5,10,15,20-tetra(4-methoxyphenyl)porphyrin ( 4b ) were used. The isothermal adsorption curves were determined, showing that the amount of adsorption decreases in the order, 1a > 1b > 1c > 1d > 2 , while neither 1e , 4a , nor 4b were adsorbed to mesoporous silicas. Mesoporous silica with the diameter of 4.0 nm adsorbed the largest amounts of biladienones. The adsorption was not observed in THF, acetone or ethanol. Neither 1c nor 1d was adsorbed to mesoporous silica with the pore diameter of 2.3 nm. These results indicate that the absorption is driven by polar interactions such as hydrogen bonding, and size exclusion effects are observed even for a molecule with flexible alkyl chains. The amount of adsorbed biladienone increased as the temperature was raised from 25 to 35 °C. The adsorption of biladien- ab -ones at 80 °C caused dehydration of biladien- ab -one to bilatrien- abc -one due to the acidity of the mesoporous silica.

A series of aluminum isopropoxide-grafted mesoporous organosilica having ethane (–CH 2 –CH 2 –) and ethene (–CH CH–) groups in the frame wall positions (ethane–silica, ethene–silica) as well as mesoporous silicas (MCM-41, MCM-48, SBA-15) through siloxide linkages were fabricated. The samples were used as catalysts in the Meerwein-Ponndorf-Verley reduction of ketones and aldehydes of different nature and size using secondary alcohols as the hydrogen transfer agents. Aluminum isopropoxide supported mesoporous silica samples show higher catalytic conversion and among them, the one-dimensionally channel oriented Si-MCM-41 supported aluminum isopropoxide shows better results than the three-dimensional Si-MCM-48 and the large pore Si-SBA-15. Compared to aluminum isopropoxide-grafted mesoporous silica samples, aluminum alkoxide-grafted organosilica samples shows better catalytic activity even in the presence of 10% of water and the better stability is attributed to the presence of integrated hydrophobic organic groups in the frame wall positions.

The phenylene-bridged hybrid mesoporous silica material with well-defined cubic three-dimensional (Pm3n) symmetry was prepared using a allylorganosilane precursor 1,4-bis(triallylsilyl)benzene and cetyltrimethylammoniumchloride (C16TMACl) surfactant in acidic medium. Sulfonic acid functionalized derivatives of 3d-cubic phenylene-bridged hybrid mesoporous silica materials were prepared and found effective in Friedel–Crafts acylation reaction. The catalytic results were also compared to the sulfonic acid functionalized derivatives of phenylene-bridged mesoporous silica with 2d-hexagonal (P6mn) symmetry, sulfonated SBA-1 (Pm3n) mesoporous silica, and sulfonated phenyltrimethoxy silane (PTMS) grafted SBA-1 (Pm3n) mesoporous silica. The degree of sulfonation could be controlled using the different sulfonating agents as well as the time on sulfonation. It was revealed that 3d-cubic mesoporous hybrids could be functionalized with higher concentration of sulfonic acid moieties. Friedel–Crafts acylation reaction was performed over all sulfonated materials. Mesoporous materials derived from allylorganosilane precursors showed an excellent activity in Friedel–Crafts acylation of aromatic ether anisol using acetic anhydride as acylating agent.

Recent studies indicate that the optimal ratio of ω-6 and ω-3 fatty acids may vary within the pathogenesis of a disease under consideration. This is consistent with the fact that noncommunicable diseases (NCDs) are polygenic and multifactorial. It seems likely that the therapeutic dose of omega-3 fatty acids will depend on the risk factor of the disease as well as on degree of severity of disease resulting from the genetic predisposition. A lower ratio of omega-6/omega-3 fatty acids is more desirable in reducing the risk of many of the NCDs of high prevalence in Western societies, as well as in the developing countries that are rapidly adopting Western dietary habits (1–3). It has been proposed that human beings evolved on a diet with a ratio of omega-6 to omega-3 essential fatty acids (EFA) of ∼1, whereas in Western diets the ratio is 15/1 to 16.7/1 and in Asia the ratio may be 1/50. Modern diets are deficient in omega-3 fatty acids and have excessive amounts of omega-6 fatty acids compared with the diet on which human beings evolved and their genetic patterns were established. Excessive amounts of omega-6 polyunsaturated fatty acids (PUFA) and a very high omega-6/omega-3 ratio, as is found in today’s modern diets, promote the pathogenesis of NCDs, including cardiovascular disease, cancer, and inflammatory and autoimmune diseases, whereas increased levels of omega-3 PUFA (a lower omega-6/omega-3 ratio) exert suppressive effects. In the secondary prevention of cardiovascular disease, a ratio of 4/1 was associated with a 70% decrease in total mortality. A ratio of 2.5/1 reduced rectal cell proliferation in patients with colorectal cancer, whereas a ratio of 4/1 with the same amount of omega-3 PUFA had no effect. The lower omega-6/omega-3 ratio in women with breast cancer was associated with decreased risk. A ratio of 2–3/1 suppressed inflammation in patients with rheumatoid arthritis, and a ratio of 5/1 had a beneficial effect on patients with asthma, whereas a ratio of 10/1 had adverse consequences. It is possible that the intake of wild foods rich in ω-3 and low in ω-6 fatty acids may also be protective, whereas Western diet and lifestyle may enhance the expression of genes related to NCDs. Our genes or pathways are most likely regulated by microRNA (2–4). It is difficult to tell which miRNA sequences might be responsible. It is possible now to apply a simple and accurate real-time PCR technique to identify miRNA expression patterns that correlate with biological phenotypes of the disease. Cardiovascular diseases (CVD), diabetes, obesity, and cancer are polygenic in nature, and their prevalences and mortality vary depending upon genetic susceptibility and presence of phenotype risk factors (1–6).