Heterogeneous Non-noble Catalyst for Highly Selective Production of Linear α-Olefins from Fatty Acids: A Discovery of NiFe/C.

Catalytic deoxygenation of even-numbered fatty acids into odd-chain linear α-olefins (LAOs) has emerged as a complementary strategy to oligomerization of ethylene, which only affords even-chain LAOs. Although enzymes and homogeneous catalysts have shown promising potential for this application, industrial production of LAOs through these catalytic systems is still very difficult to accomplish to date. A recent breakthrough involves the use of an expensive noble-metal catalyst, Pd/C, through a phosphine ligands-assisted method for LAOs production from fatty acid conversion. This study presents a unique, cost-friendly, non-noble bimetallic NiFe/C catalyst for highly selective LAOs production from fatty acids through decarbonylative dehydration. In the presence of acetic anhydride and phosphine ligand, a remarkable improvement in the yield of 1-heptadecene from the conversion of stearic acid was found over the supported bimetallic catalyst (NiFe/C) as compared to corresponding monometallic counterparts (Ni/C and Fe/C). Through optimization of the reaction conditions, a 70.1 % heptadecene yield with selectivity to 1-heptadecene as high as 92.8 % could be achieved over the bimetallic catalyst at just 190 °C. This unique bimetallic NiFe/C catalyst is composed of NiFe alloy in the material bulk phase and a surface mixture of NiFe alloy and oxidized NiFeδ+ species, which offer a synergized contribution towards decarbonylative dehydration of stearic acid for 1-heptadecene production.

Optimization of mesoporous carbons for efficient adsorption of berberine hydrochloride from aqueous solutions.

Sixteen mesoporous carbon adsorbents were synthesized by varying the ratio of soft to hard templates in order to optimize the pore textural properties of these adsorbents. The mesoporous carbon adsorbents have a high BET specific surface area (1590.3-2193.5 m(2)/g), large pore volume (1.72-2.56 cm(3)/g), and uniform pore size distribution with a median pore diameter ranging from 3.51 nm to 4.52 nm. It was observed that pore textural properties of the carbon adsorbents critically depend on the molar ratio of carbon sources to templates, and the hard template plays a more important role than the soft template in manipulating the pore textures. Adsorption isotherms of berberine hydrochloride at 303 K were measured to evaluate the adsorption efficacy of these adsorbents. The adsorption of berberine hydrochloride from aqueous solutions on the sixteen mesoporous carbon adsorbents synthesized in this work is very efficient, and the adsorption equilibrium capacities on all samples are more than double the adsorption capacities of berberine hydrochloride of the benchmark adsorbents (polymer resins and spherical activated carbons) at similar conditions. It was observed from the adsorption experiments that the equilibrium adsorption amounts of berberine hydrochloride are strongly correlated with the BET specific surface area and pore volume of the adsorbents. The adsorbent with the highest BET of 2193.5 m(2)/g displayed the largest adsorption capacity of 574 mg/g at an equilibrium concentration of 0.10mg/mL of berberine hydrochloride in an aqueous solution.

Analysis of hexavalent chromium in Colla corii asini with on-line sample pretreatment valve-switching ion chromatography.

An ion chromatography (IC) system with on-line sample pretreatment using valve-switching technique was developed for the determination of hexavalent chromium (Cr(VI)) in Colla corii asini. Colla corii asini is a complicated sample with organics as main matrix. In this work, a polymer-based reversed-phase column was used as a pretreatment column. Via valve-switching technique, sample solution with target ions were eluted from a collection loop to analytical columns, with matrix eliminated on-line. Under the optimized separation conditions, the method showed good linearity (r=0.9998) in the range of 0.004-1.0mg/L and satisfactory repeatability (RSD<3%, n=6). The limit of detection (LOD) was 1.4µg/L (S/N=3). The average spiked recoveries of Cr(VI) were 93.4-102.0%. The result showed that the on-line sample pretreatment IC system was convenient and practical for the determination of trace Cr(VI) in Colla corii asini samples.

Hypercrosslinked poly(styrene-co-divinylbenzene) resin as a specific polymeric adsorbent for purification of berberine hydrochloride from aqueous solutions.

A hypercrosslinked poly(styrene-co-divinylbenzene) resin (TEPA) was synthesized and characterized as a specific polymeric adsorbent for concentrating berberine hydrochloride from aqueous solutions. Three organic molecules of different sizes (2-naphthol, berberine hydrochloride, and Congo red) were used as target molecules to elucidate the molecular sieving effect of the TEPA adsorbent. Because the TEPA adsorbent has a pore structure consisting mainly of micropores and mesopores, the adsorption of 2-naphthol from aqueous solutions is very efficient due to the micropore filling effect. The adsorption of berberine hydrochloride mostly takes place in the mesopores as well as macropores, while the adsorption of Congo red mainly occurs in the macropores. The smaller adsorbate molecule (2-naphthol) reaches the adsorption equilibrium much faster than the larger ones (berberine hydrochloride and Congo red). An adsorption breakthrough experiment with an aqueous solution containing 2-naphthol and berberine hydrochloride demonstrated that the TEPA adsorbent could effectively remove 2-naphthol from berberine hydrochloride at 0-107 BV (bed volume, 1 BV=10 ml), and the berberine hydrochloride concentration was increased from 66.7% to 99.4%, suggesting that this polymeric adsorbent is promising for purifying berberine hydrochloride and similar alkaloids from herbal plant extracts.

Enrichment and purification of madecassoside and asiaticoside from Centella asiatica extracts with macroporous resins.

In present study, the performance and separation characteristics of five macroporous resins for the enrichment and purification of asiaticoside and madecassoside from Centella asiatica extracts have been evaluated. The adsorption and desorption properties of total triterpene saponins (80% purity) on macroporous resins including HPD100, HPD300, X-5, AB-8 and D101 have been compared. According to our results, HPD100 offered higher adsorption and desorption capacities and higher adsorption speed for asiaticoside and madecassoside than other resins. Column packed with HPD100 resin was used to perform dynamic adsorption and desorption tests to optimize the separation process of asiaticoside and madecassoside from C. asiatica extracts. After the treatment with gradient elution on HPD100 resin, the content of madecassoside in the product increased from 3.9 to 39.7%, and the recovery yield was 70.4%; for asiaticoside the content increased from 2.0 to 21.5%, and the recovery yield was 72.0%. The results showed that HPD100 resin revealed a good ability to separate madecassoside and asiaticoside, and the method can be referenced for the separation of other triterpene saponins from herbal raw materials.

Investigation on influencing factors of 5-HMF content in Schisandra.

In order to investigate the influencing factors of 5-hydroxymethyl-2-furaldehyde (5-HMF) content in Schisandra, confirm the theory of 5-HMF deriving mainly from Schisandra processing course, and give some suggestions about the Schisandra processing method, the 5-HMF contents in decoctions of Schisandra under different heating temperature, decocting time, soaking time, processing methods and treatment with different solvents before decocting the Schisandra were measured by RP-HPLC method. The results showed that there is great difference of 5-HMF level in decoctions from differently processed Schisandra and unprocessed Schisandra; decocting time of 60 min has some effects on 5-HMF level in decoctions and there is certain quantity 5-HMF in processed Schisandra itself and very little 5-HMF in unprocessed Schisandra. Heating time, heating temperature and treating solvents all have effect on 5-HMF level in decoction of Schisandra. 5-HMF in Schisandra was mainly from processing course. Both long heating time and high heating temperature can increase 5-HMF level in Schisandra. The production of 5-HMF in Schisandra may have some relationships with some polar components, which can dissolve in water, ethanol and acetone, especially in ethanol. To control processing temperature, processing time and treatment with some solvent is very important for controlling 5-HMF level in Schisandra.

[Research advances in coordination chemistry of traditional Chinese medicine].

The coordination chemistry theory of traditional Chinese medicine (TCM) plays a very important role on the research of traditional Chinese medicine. The significances of this theory applied in toxicology, pharmacology and the improvement, separation, preparation and analysis of active components in traditional Chinese medicine were summarized in this paper. The conclusions were drawn that the research on thermodynamics and dynamics of TCM coordination chemistry, the relation between existing status of microelements in TCM and toxicity or activity of TCM and the exploitation on adsorbents or chromatographic columns of high performance and high sensitivity analysis methods using the coordination effect may be the key steps in the course of modernization of TCM.

[Study on content variation of chemical constituents during combination of rhizoma coptidis alkaloids with fructus evodiae flavonoids by high performance liquid chromatography].

In order to study the compatibility of Chinese herbal drugs, a method was proposed by investigating chemical reactions with combination of chemical constituents or major groups of chemical compounds of Chinese herbal drugs. The content variation of chemical constituents during combination of rhizoma coptidis alkaloids with fructus evodiae flavonoids was analyzed by high performance liquid chromatography (HPLC). The experimental results showed that only small changes of the relative peak areas of different chemical constituents were observed and no new peaks were detected. No chemical reactions were observed during the compatibility test of rhizoma coptidis alkaloids with fructus evodiae flavonoids.

Investigation on the origin of 5-HMF in Shengmaiyin decoction by RP-HPLC method.

The origin of 5-HMF (5-hydroxymethyl-2-furaldehyde) in a Shengmaiyin decoction was investigated by the RP-HPLC method below. A C(18) column (250 mm x 4.6 mm, i.d. 5 microm) with a column temperature of 25 degrees C was used. The mobile phase was a mixture of ultra-pure water-acetonitrile (95:5, V/V) and the flow rate was 1.0 ml/min. The detection wavelength was 280 nm. The injection volume was 1 microl and the running time was about 20 min. The addition of Schisandra was regulated to assess the contribution of an acid environment to the production of 5-HMF. In order to confirm the role of saccharides in the production of 5-HMF, different amount of fructose was used. The 5-HMF level in decoctions of processed and unprocessed Schisandra was investigated in order to determine the origin of 5-HMF. The results showed that 5-HMF was derived mainly from the decoction of Schisandra only and not the mixed decoction of Ophionpogon and Schisandra. The appearance of 5-HMF is not simply the result of the decomposition of saccharides under the acid environment created by Schisandra, but the processing procedure plays an important role in the production of 5-HMF.

[Application potentials of on-line near infrared spectroscopy technology in manufacturing of traditional Chinese medicine].

The characteristics of On-line Near Infrared Spectroscopy Technology are introduced and its applications in various industries, such as petro-chemical, pharmaceutical, agriculture and food are reviewed. Considering the features in TCM manufacturing, the application potentials of On-line Near Infrared Spectroscopy Technology in Manufacturing TCM are forecasted and the key problems to be solved are discussed.