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Hesperetin glucosides such as hesperidin and hesperetin-7-glucoside are abundantly present in citrus fruits and have various pharmacological properties. However, the potential toxicity of hesperetin glucosides remains unclear. An initial assessment of the safety of hesperetin-7-glucoside–β-cyclodextrin inclusion complex (HPTGCD) as a functional food ingredient was undertaken to assess toxicity and mutagenic potential. A bacterial reverse mutation assay (Ames test) using Salmonella typhimurium (strains TA98, TA1535, TA100, and TA1537) and Escherichia coli (strain WP2 uvrA) with HPTGCD (up to 5000 µg/plate) in the absence and presence of metabolic activation was negative. In a single oral (gavage) toxicity study in male and female rats, HPTGCD at dose up to 2000 mg/kg did not produce mortality nor clinical signs of toxicity or change in body weight. In a subchronic oral (dietary admix) toxicity study in rats receiving 0, 1.5, 3, and 5% HPTGCD for 13 weeks, no adverse effects were noted and the no-observed-adverse-effect level (NOAEL) was 5% in the diet (equivalent to 3267.7 mg/kg/day for males and to 3652.4 mg/kg/day for females). These results provide initial evidence of the safety of HPTGCD.

Diosmin (DSN) is found mainly in citrus fruits, and has potent antioxidant effects. This study aimed to evaluate pharmacokinetics of diosmetin-7-glucoside-γ-cyclodextrin (DIOSG-CD) inclusion complex. The area under the curve values from AUC0-24 of DIOSG-CD, prepared by reacting DSN and naringinase with γ-CD, were approximately 800-fold higher than those of DSN following their administration in Sprague-Dawley rats.

Ginkgo biloba extract (GBE) is an essential herbal supplement for diverse health perspectives. The present study aims to improve the oral bioavailability of GBE flavonoids. We formulated the GBE flavonoids-cyclodextrin (GBE-CD) complex by reacting GBE flavonoids with naringinase in the presence of γ-cyclodextrin (CD) using a patented method. The results showed an enhanced bioavailability of quercetin (QCT), kaempferol (KAE), and isorhamnetin (ISR) after β-glucuronidase catalysis of flavonoid glucuronide conjugates in plasma after GBE-CD (25 μmol/kg as QCT equivalence) administration, that was 5.4, 6.1, and 10.4-folds, respectively, compared to GBE administration (25 μmol/kg as QCT equivalence) in Sprague–Dawley rats. In summary, the GBE inclusion into the γ-CD cavity is found suitable to improve oral bioavailability and could be applicable to several health benefits and disease prevention.

Flavonoids such as quercetin and its glucosides, especially isoquercitrin are well known as anti-inflammatory, anti-allergic, and anti-carcinogenic, etc. The safety of isoquercitrin formulations needs to be established prior to their use in functional food applications. The mutagenicity and genotoxicity of the IQC-γCD inclusion complex were assessed with three standard assays of the bacterial reverse mutation assay (Ames test) and using a combined in-vivo micronucleus and comet assay under the Organisation for Economic Co-operation and Development (OECD) guidelines. In combined rat bone marrow micronucleus and rat liver comet assay performed in male Sprague Dawley (SD) rats, the various doses of IQC-γCD inclusion complex (max. 2000 mg/kg bw) and positive controls ethyl methanesulfonate (EMS) and mitomycin C (MMC), respectively, and negative control (vehicle) were administrated. The results of the Salmonella typhimurium mutagenicity assay (strains TA100, TA1535, WP2uvrA, TA98, and TA1537) after exposure to the IQC-γCD inclusion complex with the absence and presence of the metabolic activation system (S9 fraction from rat liver) revealed a weakly positive response but with no biologically relevant mutagenicity at the conditions examined according to recommended regulatory guidelines. The combined micronucleus and comet assay results reveal that the IQC-γCD inclusion complex did not induce in-vivo genotoxic potential or indication of any oxidative DNA damage in rat liver tissues. Altogether, considering the results of the study, it is unlikely that the consumption of IQC-γCD inclusion complex as food or supplement would present any concern for humans regarding the mutagenicity and genotoxicity.

As part of the United States Pharmacopeia’s ongoing review of dietary supplement safety data, a new comprehensive systematic review on green tea extracts (GTE) has been completed. GTEs may contain hepatotoxic solvent residues, pesticide residues, pyrrolizidine alkaloids and elemental impurities, but no evidence of their involvement in GTE-induced liver injury was found during this review. GTE catechin profiles vary significantly with manufacturing processes. Animal and human data indicate that repeated oral administration of bolus doses of GTE during fasting significantly increases bioavailability of catechins, specifically EGCG, possibly involving saturation of first-pass elimination mechanisms. Toxicological studies show a hepatocellular pattern of liver injury. Published adverse event case reports associate hepatotoxicity with EGCG intake amounts from 140 mg to ∼1000 mg/day and substantial inter-individual variability in susceptibility, possibly due to genetic factors. Based on these findings, USP included a cautionary labeling requirement in its Powdered Decaffeinated Green Tea Extract monograph that reads as follows: “Do not take on an empty stomach. Take with food. Do not use if you have a liver problem and discontinue use and consult a healthcare practitioner if you develop symptoms of liver trouble, such as abdominal pain, dark urine, or jaundice (yellowing of the skin or eyes).”

The pharmacokinetics of compounds comprising hesperetin-7-glucoside with β-cyclodextrin and physically mixed hesperidin/dextrin was compared in 8 healthy adult male subjects in a nonrandomized, double-blind, cross-over, controlled study. For 0-24 h, the area under the curve of the total plasma hesperetin concentration after hesperetin-7-glucoside with β-cyclodextrin consumption was >100-fold higher than that after hesperidin/dextrin consumption.

Flavonoids such as quercetin and its glycoside Isoquercitrin and are abundantly present in the diet and have various pharmacological effects. However, limited data about its potential toxicity is available. In this study, we aim to evaluate the subchronic toxicity of the isoquercitrin-γ-cyclodextrin (IQC-γCD) molecular inclusion complex (SunActive® QCD/EN) in Sprague-Dawley (SD) rats. The IQC-γCD was administrated orally to 40 male and 40 female SD rats at dietary doses up to 5.0 % for 13 consecutive weeks. During the experiment periods, the general clinical signs, mortality, hematological, urinalysis values, biochemical, and histopathological parameters were examined. All animals survived until the scheduled necropsy, and no statistically significant or clinical sign of toxicologically relevant differences including pathology parameters, and histopathological endpoints were observed in any of the IQC-γCD treatment groups, compared with the control group. However, certain observations were noted in the male rats treated with the highest concentration (5.0 %), but these were not seen in female rats. A slight inhibition of weight gain was observed, probably linked to a fall in red blood cells, and hematocrit index in female rats. Statistically significant changes were noted in some clinical measures, such as plasma bilirubin level, alkaline phosphatase total bile acid without evidence of systemic clinical toxicity. The results support no observed adverse effect level (NOAEL) of IQC-γCD of 5.0 % in the diet for males (3338.55 mg/kg/day), and 3.0 % in the diet for females (2177.33 mg/kg/day) SD rats. Therefore, in this 13 weeks repeated-dose SD rat study there were no treatment-related adverse clinical or pathological findings for IQC-γCD of 5.0 % in the diet for males, and 3.0 % in the diet for females SD rats. The results of the present study support the safe use of IQC-γCD as a functional food, food additive, and natural ingredient.

Isoquercitrin has a higher bioavailability than quercetin and has various pharmacological effects. In the present study, we aim to elucidate the structure of the novel isoquercitrin-γ-cyclodextrin (IQC-γCD) inclusion complex derived through controlled enzymatic hydrolysis of rutin into isoquercitrin in-situ included in γ-cyclodextrin. Several vibrational, electronic and analytical spectral measurement techniques (FTIR, 1H-NMR, 13C-NMR, UV-Vis, DSC, PXRD, Raman spectroscopy, and SEM) were employed. The detailed structural comparison of the IQC-γCD inclusion complex with isolated isoquercitrin revealed the shielding of isoquercitrin –OH groups inside the γ-CD cavity, and thus, confirmed the successful formation of the inclusion complex that exhibit distinct spectroscopic features from both guest and host molecules. The phase-solubility studies showed that isoquercitrin formed a 1:1 stoichiometric inclusion complex with γ-CD. The aqueous solubility of isoquercitrin was significantly enhanced by complexation with γ-CD complex possibly due to increased isoquercitrin dissolution rate compared to the isolated isoquercitrin. The IQC-γCD inclusion could have enhanced pharmacokinetics that will be useful for future applications in functional foods and health benefits.

Catechins are a part of the chemical family of flavonoids, a naturally occurring antioxidant, and a secondary metabolite in certain plants. Green tea catechins are well recognized for their essential anti-inflammatory, photo-protective, antioxidant, and chemo-preventive functions. Ultraviolet radiation is a principal cause of damage to the skin. Studies observed that regular intake of green tea catechins increased the minimal dose of radiation required to induce erythema. The objectives of this systematic review and meta-analysis are to determine the effectiveness of green tea catechins in cutaneous erythema and elucidate whether green tea catechin consumption protects against erythema (sunburn) inflammation. A comprehensive literature search was conducted to identify the relevant studies. Two researchers carried out independent screening, data extraction, and quality assessment according to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). The pooled effect of green tea catechins on protection against erythema was assessed using approaches fixed-effects or random-effects model to quantify the effectiveness of green tea catechins in the erythema dose–response. Studies not be included in meta-analyses were summarized narratively. Six randomized controlled studies of enrolled studies regularly administrated green tea catechins orally for 6 to 12 weeks involving healthy volunteers comprising a total of 100 participants were included in the analysis. The results revealed green tea catechins have favorable protection against erythema inflammation even at increased minimal erythema dose (MED) of ultraviolet radiation. Meta-analysis results confirm oral supplementation of green tea catechins is highly effective at low-intensity ultraviolet radiation-induced erythema response (MED range; 1.25–1.30) compared to placebo, showing a significant pooling difference (p = 0.002) in erythema index (SMD: −0.35; 95% CI, −0.57 to −0.13; I2 = 4%, p = 0.40) in the random-effects model. The pro-inflammatory signaling pathways through oral supplementation with green tea catechins are an attractive strategy for photo-protection in healthy human subjects and could represent a complementary approach to topical sunscreens. Therefore, studies that involved green tea catechin in topical applications to human subjects were also evaluated separately, and their meta-analysis is presented as a reference. The evidence indicates that regular green tea catechin supplementation is associated with protection against UV-induced damage due to erythema inflammation.

Dietary fiber is part of the diet of many people worldwide and is commonly recognized as a health food. The aim of this study was to quantitatively evaluate the impact of partially hydrolyzed guar gum (PHGG) supplementation on constipation prevention related outcomes in apparently healthy individuals. An extensive electronic and manual bibliographic search of controlled trials was undertaken in PubMed, Embase, the Cochrane Library, and JST database as part of a wider scoping review from inception to September 2016, and a systematic review and meta-analysis was performed. The pooled effect of PHGG supplementation on constipation was assessed using fixed-effects or random-effects model. The outcomes of interest were fecal defecation frequency (FDF), fecal weight (FW), fecal moisture (FM), fecal volume (FV) and fecal excretory feeling (FEF). Fifteen trials of seven enrolled studies (4 RCTs & 3 non-RCTs) administrated PHGG involving only healthy volunteers comprising a total of 325 participants, indicated that PHGG has a favorable efficacy success rate of constipation reduction, while no adverse events were observed in context of the studies included. Trials revealed a highly significant statistically pooling difference (P

Green tea catechins (GTCs) are known to improve fat oxidation (FOX) during fasted, rested and exercise conditions wherein epigallocatechin-3-gallate (EGCG) is thought to be the most pharmacologically active and has been studied extensively. From the available data of randomized controlled trials (RCTs) on EGCG, we carried out a systematic review and meta-analysis to elucidate whether EGCG consumption indeed increase energy expenditure (EE) and promote FOX. A systematic review of the literature was conducted using electronic databases (PubMed, Embase, Cochrane Library, CINAHL, JICST, JSTPLUS, and JMEDPLUS and others) and eight RCTs were included. RCTs were reviewed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and methodological quality was assessed. After data extraction, results were aggregated using fixed- and random-effect approaches and expressed to quantify the relationship between the dose of EGCG for respiratory quotient (RQ), EE and rate of FOX to compare the EGCG and placebo treatments. The meta-analysis results of verities of studies in terms of dose and length of duration revealed that EGCG supplementation provided significant mean difference (MD) when compared with placebo for RQ [MD: -0.02; 95% confidence intervals (95% CI), -0.04 to 0.00; I2=67%; P=.01] and EE [MD: 158.05 kJ/day; 95% CI, 4.72 to 311.38; I2=0%; P=.04] in fixed-effect approach. Changes in FOX did not reach the level of statistical significance. Meta-analyses of EGCG influence on the body mass index, waist circumference and total body fat mass (TBFM) were also examined and their impact on the promotion of FOX is reported. Effect of EGCG doses was also systematically reviewed. Finding showed that EGCG intake moderately accelerates EE and reduces RQ. The analyses revealed that the EGCG resulted in difference in RQ and EE but the effect on the other measures of energy metabolism was relatively mild. Possibly, EGCG alone has the potential to increase metabolic rate at 300 mg dose. Collectively, the outcome supports the findings that EGCG has an effect on metabolic parameters. However, the large prospective trials are needed to confirm the findings.

Dietary fibre intakes have consistently been associated with reduced risk of diabetes and metabolic syndrome. We investigated in 12 healthy subjects if administration of dietary fibre partially hydrolysed guar gum (PHGG) induces beneficial impact on hyperglycaemia, hyperlipidaemia and incretins metabolic hormones. Administration of 6 g/PHGG with each meal for 12 months significantly lowered the postprandial plasma glucose (PG), reduced both the fasting and postprandial insulin (IRI) and triacylglycerol (TG) levels (p = 0.05). Low-density lipoprotein (LDL) was lower, whereas high-density lipoprotein (HDL) level was significantly increased (p

OBJECTIVES: The widespread impact of the gut microbiota in human health has emerged in recent years. Changes in diet and exercise can alter the gut microbiomes of active athletes. We performed a randomized, controlled study to evaluate the relationship between the partially hydrolyzed guar gum (PHGG) prebiotic dietary fiber and the relative abundance of the gut microbiomes in the context of changes in lifestyle-related factors, and their significant correlation with fecal defecation characteristics in healthy athletes. METHODS: Subjects followed a daily 6 grams dietary intake of either PHGG or placebo for four weeks, following a three weeks washout period, subjects followed another four weeks of crossover alternative administration. Fecal defecation characteristics were assessed using a questionnaire along with the quality of life (QOL) questions and gut microbiome abundance was determined by 16S rRNA gene sequencing and real-time PCR analysis. RESULTS: The alteration in gastrointestinal microbiomes relative abundance was correlated to representative changes in fecal defecation characteristics, especially in ameliorating diarrhea (P = 0.035) and fecal excretory feeling (P = 0.038). The PHGG intake led to a significant increase in phylum Actinobacterium (P = 0.04), along with a significant decrease in Bacteroidetes (P = 0.036). A trending decrease in Firmicutes (P = 0.09) Awas noticed. Also, a significant alteration in the relative abundance of Bifidobacterium (P = 0.047) and Clostridium subcluster XI (P = 0.044) were observed with PHGG intake compared with placebo. Principal component analysis and hierarchical clustering analysis represented a clear overview of the distribution of quality of life covariates evaluated in the study. CONCLUSIONS: Improved diarrhea was associated with the relative abundance of phylum Firmicutes/Bacteroidetes ratio and genera Bacteroides/Prevotella ratio for the PHGG intervention compared to placebo. The finding reveals that even at relatively low dosage, intake of prebiotic PHGG fiber modulates gut microbiomes, and thus improves gastrointestinal health. Overall, the quality of lifestyle factors was significantly improved with PHGG consumption. FUNDING SOURCES: Taiyo Kagaku, University of Tsukuba, and Otsuma Women's University equally contributed to the study.

Partially hydrolysed guar gum (PHGG), a soluble dietary fibre, has been shown to provide many health benefits. Previous studies had suggested that the combination of PHGG with protein provided a significant satiation effect on visual analogue scales (VAS). What was lacking was only the effect of administration of small doses of PHGG on post-meal satiation and subsequent energy intake. The objectives of the present investigations were to find the subjective perception of post-meal satiety with acute and long term administration of small amounts of PHGG alone with food, its effects on subsequent energy intake and the comparative effects among different types of soluble fibres. The following three separate studies were conducted: in study 1, healthy subjects (n 12) consumed PHGG along with breakfast, lunch and an evening snack; in study 2, healthy subjects (n 24) consumed 2 g of PHGG or dextrin along with yogurt as breakfast for 2 weeks; in study 3, healthy subjects (n 6) took 6 g each of either PHGG or indigestible dextrin or inulin along with lunch. In all the studies, various satiety parameters were measured on VAS before and after consumption of PHGG. The addition of PHGG showed significant (PP

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 present study reports the divergent synthesis, characterization and catalytic properties of different generation of triazine based aromatic amine dendritic mesoporous silicas derived via a stepwise functionalization of mesoporous silica substrates of different pore sizes with 2,4,6 tricholorotriazine and ethylene diamine. Mesoporous dendritic silicas up to second generation (2G) are grown in side the channels of mesoporous silica materials with 4 and 7 nm pore sizes. The catalytic properties of resulted dendritic materials in Knoevenagel condensation reaction were compared to the aliphatic polyamidoamine dendrimers that are also grown up to second generation (2G) inside the mesoporous channels. The reusability study of both aliphatic and aromatic dendritic mesoporous silica systems is also compared.

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.

An environmental friendly synthetic method for the rapid mass production of nanometer sized highly ordered mesoporous silica materials is presented. A systematic control in hydrolysis and polycondensation reactions during the synthesis is designed by employing combined acid–base and evaporation approach. The uniformed nanoscale silica particles with bulk average size 100–150 nm could be prepared with highly ordered mesoporous structure, while TEM results indicate that the nano particles even less than 70 nm are abundantly present. Also, the approach is environmentally friendly and minimize the production of waste wherein necessitates aqueous quenching and neutralization steps to remove an acid and washing out the surfactant is not required, and thus effectively reduces the emission of hazardous waste and pollutants and maintains economic viability of the process.

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.

The surfactant assistant syntheses of sulfonic acid functionalized periodic mesoporous organosilicas with large pores are reported. A one-step condensation of tetramethoxysilane (TMOS) with 1,2-bis(trimethoxysilyl)ethane (BTME) and 3-mercaptopropyltrimethoxysilane (MPTMS) in highly acidic medium was performed in the presence of triblock copolymer Pluronic P123 and inorganic salt as additive. During the condensation process, thiol (-SH) group was in situ oxidized to sulfonic acid (-SO(3)H) by hydrogen peroxide (30 wt % H(2)O(2)). X-ray diffraction studies along with nitrogen and water sorption analyses reveal the formation of stable, highly hydrophobic, and well-ordered hexagonal mesoscopic structures in a wide range of -CH(2)CH(2)- concentrations in the mesoporous framework. The resultant materials were also investigated by (29)Si MAS and (13)C CP MAS NMR, thermogravimetric analyses, UV-Raman spectroscopy, and FT-IR spectroscopy. The role of the bridged organic group on the hydrothermal stability of the mesoporous materials was established, which revealed an enhancement in hydrothermal stability of the materials with incorporation of the bridged organic groups in the network. The catalytic performance of -SO(3)H functionalized mesoporous materials was investigated in the esterification of ethanol with acetic acid, and the results demonstrate that the ethane groups incorporated in the mesoporous framework have a positive influence on the catalytic behavior of the materials.

The bridged allylorganosilanes 1,4-bis(diallylethoxysilyl)benzene and 1,4-bis(triallylsilyl)benzene are presented as new precursors for the surfactant-assisted synthesis of ordered mesoporous organosilica with pore walls having crystal-like molecular-scale periodicity. This approach provides a new route to the formation of periodic mesostructures with crystal-like pore walls. The synthesis method presented is applicable to the preparation of mesoporous organosilica with bulky organic groups, the precursors of which are typically impossible to obtain in high purity.

Syntheses of mesoporous zirconium−titanium phosphates (ZTP) are described under a wide range of synthetic parameters. The ZTP materials showed ordered mesophases whose pore walls are either amorphous or show a lack of correspondence between the structures of adjacent pores. However, the materials showed the reasonable thermal and hydrothermal stability, high specific surface areas, narrow pore size distribution, and considerable pore volumes in the mesophases range. UV−visible and XANES results confirmed the presence of tetrahedrally coordinated zirconium and titanium in the mesoporous framework. 31P NMR measurements provide the details on the coordination structure of Ti, Zr, O, and P connectivities in the mesoporous frameworks. Finally, the ZTP materials demonstrated the considerable activity in photocatalytic decomposition of water for hydrogen generation.

The first catalytic applications of sulfonic acid-functionalized hydrophobic mesoporous benzene–silica with lamellar pore wall structure are reported. The mesoporous benzene–silica attached with propylsulfonic groups to the crystal-like periodic pore walls exhibited the catalytic activity in the esterification of acetic acid with ethanol. The catalytic results show the higher conversion compared to the commercial Nafion-H.

Sulfonic acid-functionalized periodic mesoporous organosilicas were synthesized directly by cocondensation of (R′O) 3 Si R Si(OR′) 3 (R = CH 2 CH 2 and C 6 H 4 ; R′ = CH 3 and C 2 H 5 ) with 3-mercaptopropyltrimethoxysilane (MeO) 3 SiCH 2 CH 2 CH 2 SH in the presence of H 2 O 2 using nonionic oligomeric polymer surfactant C 18 H 37 (OCH 2 CH 2 ) 10 OH in acidic medium. The sulfonic acid functionalities ( SO 3 H) were generated in situ by oxidation of the propylthiol using H 2 O 2 as oxidant during the synthesis process. Powder X-ray diffraction patterns and nitrogen sorption indicate the formation of well-ordered mesoporous material with uniform porosity. The highest acid-exchange capacity (acid–base titration methods) was 1.72 H + mmol/g. Complete oxidation of SH to SO 3 H was observed as evidenced by X-ray photoelectron spectroscopy. For comparison, the sulfonic acid-functionalized mesoporous organosilicas were also prepared by a grafting method. The catalytic properties of the materials were investigated in liquid-phase condensation of phenol with acetone to form Bisphenol A. All sulfonic acid-functionalized mesoporous organosilicas show high catalytic activity. The highest TOF obtained for the mesoporous organosilica is 17.2.

A nickel–aluminum layered double hydroxide (LDH), of which structure is similar to that of hydrotalcite, has been synthesized. Liquid-phase carbonylation of methanol to methyl acetate is catalyzed over the LDH in presence of methyl iodide at 473 K. Dimethyl ether is also formed in the reaction, but formation of acetic acid is undetectable. Nickel ions in the LDH can be replaced with tin ions, and the presence of tin significantly promotes the activity of the LDH. Formation of methyl formate depends on the pressure of carbon monoxide in the reaction, suggesting that insertion of carbon monoxide to methyl iodide is a key step of the carbonylation and dimethyl ether reacts with the intermediate to form methyl formate.

Addition of gold to palladium by simultaneous deposition–precipitation on cerium oxide increases the catalytic activity for methanol decomposition to carbon monoxide and hydrogen at 180 °C. No significant promotional effect was observed by addition of rhodium or iridium to palladium. The electronic state or dispersion of palladium is unchanged by the addition of gold, suggesting presence of new active sites. Bimetallic clusters of Pd–Au can be formed by the addition of gold, but an excessive amount of gold results in formation of fairly large gold particles on the support. The increase in the activity does not relate to the number of the gold particles and addition of a small quantity of gold significantly promotes the reaction, suggesting that the bimetallic clusters are highly active in the methanol decomposition.

Synthesis of a highly ordered, two-dimensional hexagonal (P6mm) mesoporous benzene−silica composite having molecular-scale periodicity in the pore wall from the self-assembly of nonlinear symmetric 1,3-bis(triethoxysilyl)benzene and octadecyltrimethylammonium surfactant is described. The synthesis of hybrid organosilicas with mesoscopically ordered pores and molecularly ordered pore walls is not confined only to the symmetrically linear bridged organosilane precursors such as 1,4-bis(triethoxysilyl)benzene but a similar arrangement can also be formed by using nonlinear symmetric bridged organosilane precursors.

Thermally stable mesoporous titanium oxide can be synthesized under non-aqueous conditions by reacting a sodium–glycotitanate(IV) complex and hexadecylamine in ethylene glycol. The mesoporous structure is retained after calcination in air at 350 °C for 5 h. Modification of the compound with palladium by the deposition–precipitation method results in formation of ultrafine palladium particles. Although a fairly large part of the particles are considered to be confined in the blind pores, the catalytic activity for methanol decomposition to carbon monoxide and hydrogen is significantly higher than that of palladium supported on a commercial titanium oxide.

Ultrafine palladium particles can be deposited on mesoporous cerium oxide by a deposition–precipitation method. After reduction with hydrogen at 300 °C, palladium on the mesoporous compound is cationic with a valence close to +1 whereas the particles have a metallic structure. The catalytic activity in selective methanol decomposition to hydrogen and carbon monoxide at 180 °C is significantly higher than that of palladium supported on non-porous cerium oxide, suggesting that the mesoporous structure is advantageous to the reaction. When the palladium content is high, part of mesopores are probably choked with large palladium particles, which will cause saturation of the activity.