Aim To design a practical synthetic route of anisodine. Methods Starting from3α-hydroxy-6β-acetyltropine, anisodine was synthesized in 11 steps. Result Anisodine wasobtainded with an overall yield of 2.6 % . Conclus...Aim To design a practical synthetic route of anisodine. Methods Starting from3α-hydroxy-6β-acetyltropine, anisodine was synthesized in 11 steps. Result Anisodine wasobtainded with an overall yield of 2.6 % . Conclusion Total synthetic route of anisodine wasachieved which may afford a possible route for commercial preparation of anisodine.展开更多
Aim To study the chemical constituents of Buddleja lindeyana. Methods The constituents were separated and purified by different methods of chromatography, and their structures were elucidated by IR, MS and NMR. Result...Aim To study the chemical constituents of Buddleja lindeyana. Methods The constituents were separated and purified by different methods of chromatography, and their structures were elucidated by IR, MS and NMR. Results Three iridoid glycosides and two other compounds were isolated from Buddleja lindeyana. Their structures were elucidated to be 6-O-feruloylajugol ( 1 ), erythro-6-oxo-4′-( 3-methoxyl-4-hydroxyphenylglycol-8')-feruloylaj-ugol ( 2 ), threo-6-oxo-4′-(3-methoxyl-4-hydroxyphenylglycol-8')-feruloylajugol ( 3 ), tetra-cosanoic acid 2,3-dihydroxypropyl ester (4), and galactitol (5). Conclusion All the compounds have been isolated from this plant for the first time. Compounds 1, 2 and 3 have protective effect agains MPP+ -induced apoptosis.展开更多
In this paper we present a strategy for tuning the crystal morphology of pharmaceutical compounds by the appropriate choice of solvent via an optimization model. A three-stage approach involving a pre-design stage, a ...In this paper we present a strategy for tuning the crystal morphology of pharmaceutical compounds by the appropriate choice of solvent via an optimization model. A three-stage approach involving a pre-design stage, a product design stage and a post-design experimental verification stage is presented. The pre-design stage addresses the tormulation of the property constraint tor crystal morphology. This involves crystallization experiments aria development of property models and constraints for morphology. In the design stage various property requirements for the solvent along with crystal morphology are considered and the product design problem is formulated as a mixed integer nonlinear programming model.The design stage provides an optimal solvent/list of candidate solvents. Similar to the pre-design stage, in the post design experimental verification stage, the morphology of the crystals （precipitated from the designed solvent） is verified through crystallization experiments followed by product characterization via scanni＇ng electron microscopy, powder X-ray diffraction imaging and Fourier transform spectra analysis.展开更多
It has long been recognized that plant invasions may alter carbon （C） and nitrogen （N） cycles, but the direction and magnitude of such alterations have been rarely quantified. In this study, we quantified the effe...It has long been recognized that plant invasions may alter carbon （C） and nitrogen （N） cycles, but the direction and magnitude of such alterations have been rarely quantified. In this study, we quantified the effects caused by the invasion of a noxious exotic plant, Kalanchoe daigrernontiana （Crassulaceae）, on C and N mineralization and enzymatic and microbial activities in the soil of a semiarid locality in Venezuela. We compared soil parameters associated with these processes （C and N mineralization time and the cumulative values, fluorescein diacetate hydrolytic activity, and activities of dehydrogenase, β-glucosidase, glucosaminidase, and urease） between invaded and adjacent non-invaded sites. In addition, correlations among these parameters and the soil physical-chemical properties were also examined to determine if a positive feedback exists between nutrient availability and K. daigremontiana invasion. Overall, our results showed that C mineralization and transformation of organic compounds to NH4^＋ were favored at sites colonized by K. daigrernontiana. With this species, we found the highest cumulative amounts of NH4^＋-N and C and the lowest mineralization time. These results could be explained by higher activities of urease and glueosaminidase in soils under the influence of K. daigremontiana. In addition, higher amounts of organic matter and moisture content in invaded soils might favor C and N mineralization. In conclusion, invasion of Neotropical semiarid zones by K. daigrernontiana may influence the chemical and biological properties of the soils covered by this species, increasing nutrient bioavailability, which, in time, can facilitate the invasion process.展开更多
Since aptamer and its in vitro selection process called SELEX were independently described by Ellington and Gold in 1990, extensive research has been undertaken and numerous isolated aptamers for various targets have ...Since aptamer and its in vitro selection process called SELEX were independently described by Ellington and Gold in 1990, extensive research has been undertaken and numerous isolated aptamers for various targets have been applied. Aptamers can bind to a wide range of targets that include small organic molecules, inorganic compounds, haptens and even whole cells with high binding affinity and specificity. Aptamers for a wide range of targets have been selected currently. In addition, aptamers are thermo stable and can also be regenerated easily within a few minutes denaturation, which makes them easy to store or handle. These advantages make aptamers extremely suitable for applications based on molecular recognition as analytical, diagnostic and therapeutic tools. In this review, the recent applications of aptamers for chemistry analysis, medicine and food security, along with the future trend will be discussed.展开更多
文摘Aim To design a practical synthetic route of anisodine. Methods Starting from3α-hydroxy-6β-acetyltropine, anisodine was synthesized in 11 steps. Result Anisodine wasobtainded with an overall yield of 2.6 % . Conclusion Total synthetic route of anisodine wasachieved which may afford a possible route for commercial preparation of anisodine.
文摘Aim To study the chemical constituents of Buddleja lindeyana. Methods The constituents were separated and purified by different methods of chromatography, and their structures were elucidated by IR, MS and NMR. Results Three iridoid glycosides and two other compounds were isolated from Buddleja lindeyana. Their structures were elucidated to be 6-O-feruloylajugol ( 1 ), erythro-6-oxo-4′-( 3-methoxyl-4-hydroxyphenylglycol-8')-feruloylaj-ugol ( 2 ), threo-6-oxo-4′-(3-methoxyl-4-hydroxyphenylglycol-8')-feruloylajugol ( 3 ), tetra-cosanoic acid 2,3-dihydroxypropyl ester (4), and galactitol (5). Conclusion All the compounds have been isolated from this plant for the first time. Compounds 1, 2 and 3 have protective effect agains MPP+ -induced apoptosis.
文摘In this paper we present a strategy for tuning the crystal morphology of pharmaceutical compounds by the appropriate choice of solvent via an optimization model. A three-stage approach involving a pre-design stage, a product design stage and a post-design experimental verification stage is presented. The pre-design stage addresses the tormulation of the property constraint tor crystal morphology. This involves crystallization experiments aria development of property models and constraints for morphology. In the design stage various property requirements for the solvent along with crystal morphology are considered and the product design problem is formulated as a mixed integer nonlinear programming model.The design stage provides an optimal solvent/list of candidate solvents. Similar to the pre-design stage, in the post design experimental verification stage, the morphology of the crystals （precipitated from the designed solvent） is verified through crystallization experiments followed by product characterization via scanni＇ng electron microscopy, powder X-ray diffraction imaging and Fourier transform spectra analysis.
基金supported by the Venezuelan Institute for Scientific Research to the first author
文摘It has long been recognized that plant invasions may alter carbon （C） and nitrogen （N） cycles, but the direction and magnitude of such alterations have been rarely quantified. In this study, we quantified the effects caused by the invasion of a noxious exotic plant, Kalanchoe daigrernontiana （Crassulaceae）, on C and N mineralization and enzymatic and microbial activities in the soil of a semiarid locality in Venezuela. We compared soil parameters associated with these processes （C and N mineralization time and the cumulative values, fluorescein diacetate hydrolytic activity, and activities of dehydrogenase, β-glucosidase, glucosaminidase, and urease） between invaded and adjacent non-invaded sites. In addition, correlations among these parameters and the soil physical-chemical properties were also examined to determine if a positive feedback exists between nutrient availability and K. daigremontiana invasion. Overall, our results showed that C mineralization and transformation of organic compounds to NH4^＋ were favored at sites colonized by K. daigrernontiana. With this species, we found the highest cumulative amounts of NH4^＋-N and C and the lowest mineralization time. These results could be explained by higher activities of urease and glueosaminidase in soils under the influence of K. daigremontiana. In addition, higher amounts of organic matter and moisture content in invaded soils might favor C and N mineralization. In conclusion, invasion of Neotropical semiarid zones by K. daigrernontiana may influence the chemical and biological properties of the soils covered by this species, increasing nutrient bioavailability, which, in time, can facilitate the invasion process.
基金supported by the 863 Project(2012AA022703,2015AA020502)the National Natural Science Foundation of China(61271056)
文摘Since aptamer and its in vitro selection process called SELEX were independently described by Ellington and Gold in 1990, extensive research has been undertaken and numerous isolated aptamers for various targets have been applied. Aptamers can bind to a wide range of targets that include small organic molecules, inorganic compounds, haptens and even whole cells with high binding affinity and specificity. Aptamers for a wide range of targets have been selected currently. In addition, aptamers are thermo stable and can also be regenerated easily within a few minutes denaturation, which makes them easy to store or handle. These advantages make aptamers extremely suitable for applications based on molecular recognition as analytical, diagnostic and therapeutic tools. In this review, the recent applications of aptamers for chemistry analysis, medicine and food security, along with the future trend will be discussed.
