Synthesis, structure, and photophysics of copper(i) triphenylphosphine complexes with functionalized 3-(2'-pyrimidinyl)-1,2,4-triazole ligands.

A series of new mononuclear and dinuclear copper(i) triphenylphosphine complexes with functionalized 3-(2'-pyrimidinyl)-1,2,4-triazole ligands have been synthesized and characterized, in which functionalized 3-(2'-pyrimidinyl)-1,2,4-triazole adopts neutral mono- and bis-chelating coordination modes and a mono-anionic bis-chelating binding manner due to the 1,2,4-triazolyl-NH deprotonation. All these Cu(i) complexes display a relatively weak low-energy absorption in a CH2Cl2 solution, ascribed to the charge-transfer transitions with appreciable MLCT character, as suggested by TD-DFT analyses. These Cu(i) complexes are all emissive in solution and in the solid state at ambient temperature, and their luminescence properties can be well modulated via the addition of the second {Cu(PPh3)2} unit and modification of 3-(2'-pyrimidinyl)-1,2,4-triazole involving the N-H deprotonation and the substituent variation of the 1,2,4-triazolyl ring. It is also demonstrated that introducing the trifluoromethyl group into the 1,2,4-triazolyl ring is helpful for enhancing the solid-state luminescence properties of the 1,2,4-triazole-based Cu(i) complexes, whereas the introduction of the tert-butyl group into the 1,2,4-triazolyl ring, the 1,2,4-triazolyl-NH deprotonation, and the use of the pyrimidinyl ring instead of the pyridyl ring are all unfavorable.

New and highly efficient column chromatographic extraction and simple purification of camptothecin from Camptotheca acuminata and Nothapodytes pittosporoides.

INTRODUCTION: Camptothecin, a widely used natural anti-cancer drug, is difficult to extract and purify effectively from plants. OBJECTIVE: To develop new and highly efficient extraction and purification methods for analysis and production of camptothecin from leaves and fruits of Camptotheca acuminata and Nothapodytes pittosporoides roots. METHODS: Dried materials were loaded in empty columns with fivefold 60% ethanol for leaves or 70% ethanol for fruits of C. acumnata, and sixfold 70% ethanol for N. pittosporoides roots. The columns were eluted with the same solvents at room temperature. Eluent was collected as extraction solution. Extraction solution from leaves and fruits of C. acuminata was vacuum-evaporated to remove ethanol, precipitated at pH 8.0 to remove alkaline insolubles and fractionated with chloroform at pH 3.0, which yields a crude product with 70% purity. Extraction solution from N. pittosporoides roots was concentrated to 1/10 volume and precipitated at pH 3.0, which yields a crude product with 60% purity. All crude products were purified by crystallisation. All steps were monitored by HPLC. RESULTS: Camptothecin was extracted from the three plant materials at a 98% rate with 15- or 18-fold solvent for content analysis, or at a 97% rate with five- or sixfold solvent for production. All crude products were purified to 98%. The overall recovery rates of camptothecin from plant materials to purified products reached 92% or higher. CONCLUSION: The new procedures are simple and highly efficient, and have multiple advantages for quantitative analysis and large production of camptothecin from plants.

High-efficient column chromatographic extraction of curcumin from Curcuma longa.

Curcumin is an important food additive and a potential therapeutic agent for various diseases from turmeric, the rhizome of Curcuma longa L. High-efficient column chromatographic extraction (CCE) procedures were developed for the extraction of curcumin from turmeric. Turmeric powder was loaded into a column with 2-fold 80% ethanol. The column was eluted with 80% ethanol at room temperature. For quantitative analysis with a non-cyclic CCE, 8-fold eluent was collected as extraction solution. For large preparation with a cyclic CCE, only the first 2-fold of eluent was collected as extraction and other eluent was sequentially circulated to the next columns. More than 99% extraction rates were obtained through both CCE procedures, compared to a 59% extraction rate by the ultrasonic-assisted maceration extraction with 10-fold 80% ethanol. The CCE procedures are high-efficient for the extraction of curcumin from turmeric with minimum use of solvent and high concentration of extraction solution.