Preparation and analysis of photochromic behavior of carboxymethyl chitin derivatives containing spiropyran moieties.

1'-(2-Acryloxyethyl)-3,3'-dimethyl-6-nitrospiro[2 H-1-benzopyran-2,2'-indoline] (SPA) was synthesized and grafted onto a water-soluble carboxymethyl chitin (CMCH) macromolecule to prepare a photochromic copolymer (CMCH-g-SPA). The structure of CMCH-g-SPA was characterized by Fourier-transform infrared (FT-IR) spectroscopy, thermogravimetric (TG) analysis, X-ray diffraction (XRD) analysis, water-solubility evaluation, and UV-vis spectroscopy. XRD patterns of CMCH-g-SPA revealed that grafting copolymerization disrupts the CMCH semicrystalline structure, thus improving water solubility. UV-vis spectroscopy results supported the negative photochromic behavior of the merocyanine (MC) form of CMCH-g-SPA (CMCH-g-MCA) present in a water solution of the target copolymer. In addition to high solvent polarity, the intermolecular and intramolecular electrostatic attraction between the indolenine cation and the COO- anion were found to be influencing factors, which stabilize these MC form of spiropyran groups grafted onto CMCH. In a water solution, visible light bleaching was completed over a short period (8 minutes) under artificial visible light irradiation and the thermal coloration reaction, whose rate constant at 25 °C was 4.64 × 10-4 s-1, which fit the first-order reaction equation. After ten photochromic cycles in water solution, the relative absorption intensity of CMCH-g-MCA decreased by 7.92%.

Honatisine, a novel diterpenoid alkaloid, and six known alkaloids from Delphinium honanense and their cytotoxic activity.

A novel diterpene alkaloid named honatisine (1) has been isolated from the whole plants of Delphinium honanense, along with six known alkaloids, siwanine E (2), isoatisine (3), atisine (4), delcorinine (5), uraphine (6), and nordhagenine A (7). Their structures were deduced on the basis of their spectral data. All of them were evaluated by a SRB assay for their cytotoxicity, and compound 1 showed a significant cytotoxic activity (IC(50) =3.16 µM) against the MCF-7 cell line.

Diterpenoid alkaloids from a Tibetan medicinal plant Aconitum richardsonianum var. pseudosessiliflorum and their cytotoxic activity.

The chemical constituents from Aconitum richardsonianum var. pseudosessiliflorum were investigated. The roots of this plant were extracted three times with 90% EtOH at the room temperature. The ethanol extracts were combined and concentrated under reduced pressure to yield residue, which was suspended in water and successively partitioned with chloroform. The chloroform extraction was isolated and purified by silica gel and Sephadex LH-20 column chromatography. Six compounds were isolated and elucidated as delelatine (1), isodelpheline (2), 3-acetylaconitine (3), isoatisine (4), nordhagenine A (5) and yunaconitine (6). Compounds 1-5 were obtained from Aconitum Brunneum for the first time. Compound (1) showed significant cytotoxic activities (IC50= 4.36 µM) against the human tumor cell line P388.

Chemical constituents from Delphinium chrysotrichum and their biological activity.

A new diterpene alkaloid named delphatisine C (1) has been isolated from aerial parts of Delphinium chrysotrichum along with three known norditerpenoid alkaloids delpheline (2), delbrunine (3), and delectinine (4). Their structures were characterized on the basis of their spectral data. All of them were determined by SRB assay for their cytotoxicity, and compound (1) showed significant cytotoxic activities (IC(50)=2.36 µmol/L) against the A549 cell line.

[Transport kinetics of Pb(II) through bulk liquid membrane using PC-88A as carrier].

The effects of stirring speed, carrier concentration and reaction temperature on the transport of Pb(II) ion through bulk liquid membrane were studied with chloroform as membrane solvent and 2-ethylhexyl phosphonic acid-mono-2-ethylhexylester as carrier. The Pb(II) ions concentrations of feed phase and stripping phase were assayed by atomic absorption spectroscopy. The kinetic parameters, including apparent rate constants of Pb(II) ion extraction and re-extraction reactions, the maximum concentration of Pb(II) ion in the liquid membrane, the time of the maximum value of maximum concentration of Pb(II) ion in the liquid membrane and the maximum entry and exit fluxes of Pb(II) ion through the liquid membrane of the extraction and stripping reactions, were evaluated. The apparent activation energy value is 31.65 kJ x mol(-1) for extraction and 23.11 kJ mol(-1) for stripping. The results indicate that good agreement between experimental data and theoretical predictions could be achieved and the kinetics of Pb(II) transport could be evaluated by two consecutive irreversible pseudo-first order reactions. In this condition the chemical reaction is a procedure of controlled reaction rates.

A new norditerpenoid alkaloid from Aconitum taipaicum.

To investigate the chemical constituents of the roots of Aconitum taipaicum, silica gel column chromatography was used for the isolation and purification of compounds. A new norditerpenoid alkaloid, isodelelatine (1), along with five known alkaloids, atisine (2), delfissinol (3), liangshanine (4), hypaconitine (5) and delelatine (6) were isolated and identified. The structure of the new compound was elucidated on the basis of spectral data.

[Study on chemical constituents from Delphinium honanense var. piliteram].

OBJECTIVE: To study the chemical constituents from Delphinium honanense var. piliteram. METHOD: The constituents were isolated and purified with chromatographic methods, identified by NMR, MS and IR. RESULT: Six compounds were isolated and elucidated as siwanine E (1), isoatisine (2), 12-epi-napelline (3), acontine (4), ajadelphinine (5) and beta-sitosterol (6). CONCLUSION: Compounds 1-6 are all isolated from the plant for the first time.

[Studies on preparation of CdS/TiO2/float pearls coupled photocatalyst and degradation of beta-cypermethrin].

The coupled photocatalyst of CdS/TiO2/float pearls was prepared by sol-gel-dipping method, and its structure characterization was carried out with SEM and XRD analysis. As a model reaction, the photocatalytic degradation of beta-cypermethrin (BEC) was investigated in CdS/TiO2/float pearls powder suspension irradiated by different light sources. The effects of influence factors on the photocatalytic activity were discussed for the prepared photocatalyst. The results showed that under the following conditions: amount of photocatalyst 3000 mg x L(-1), initial concentration of BEC 45 mg x L(-1), initial pH 6. 5, and air flow rate 200 mL x min(-1), the degradation rate of BEC reached 87.9% (125 W Hg lamp in 1 hour), 79.3% (5 W UV lamp in 1 hour) and 93.4% (solar light in 5 hours), respectively. The photocatalytic degradation of BEC was experimentally demonstrated to follow the Langmuir-Hinshelwood kinetic model, and the reaction rate constant (9.80 mg x (L x min)(-1)) and the adsorption constant (4.36 x 10(-3) L x mg(-1)) were determined, respectively.

[Research development of catalytic-kinetic spectrophotometric determination of trace manganese].

A review of recent research progresses in the determination of trace amount of manganese with catalytic-kinetic spectrophotometric method is presented and discussed in the present paper. Firstly, by comparison it is showed that catalytic-kinetic spectrophotometry has more advantages than atomic absorption spectrophotometry and extraction-spectrophotometry for the determination of trace amounts of manganese. The review and discussion of the recent research developments in the catalytic discoloring spectrophotometry and catalytic coloring spectrophotometry for the determination of trace amounts of manganese are given respectively. Finally the development trends and application perspectives for the catalytic-kinetic spectrophotometry in the future are discussed and probed. Twenty five references are cited.

[A study on preparation and characteristic of RuO2/TiO2 coupled photocatalyst].

RuO2/TiQ2 coupled photocatalyst was prepared by sol-gel-dipping method. Being a model reaction, the photocatalytic degradation of direct fast black G was investigated in RuO2/TiO2 powder suspension irradiated by UV-lamp. The results showed that the addition of RuO2 to TiO2 greatly enhanced its photocatalytic activity, and the optimum dipped content of RuO2 was 0.16%, the optimum value of the calcinations temperature and the addition of RuO2/TiO2 powder were 500 degrees C and 5.00 g x L(-1), respectively. The photocatalytic degradation of direct fast black G was experimentally demonstrated to follow the Langmuir-Hinshelwood kinetic model, and the adsorption constant (14.22 L x mmol(-1)) and the reaction rate constant [4.94 x 10(-3) mmol(L x min)(-1)] were determined, respectively.