We previously isolated a natural product, namely guaiazulene-2,9-dione showing strong antibacterial activity against Vibrio anguillarum, from a gorgonian Muriceides collaris collected in South China Sea. In this exper...We previously isolated a natural product, namely guaiazulene-2,9-dione showing strong antibacterial activity against Vibrio anguillarum, from a gorgonian Muriceides collaris collected in South China Sea. In this experiment, guaiazulene-2,9-dione was quantitatively synthesized with an optimized one-step bromine oxidation method using guaiazulene as the raw material. The key reaction condition including reaction time and temperature, drop rate of bromine, concentration of aqueous THF solution, respective molar ratio of guaiazulene to bromine and acetic acid, and concentration of guaiazulene in aqueous THF solution, were investigated individually at five levels each for optimization. Combined with the verification test to show the absolute yield of each optimization step, the final optimal condition was determined as: when a solution of 0.025 mmol m L-1 guaiazulene in 80% aqueous THF was treated with four volumes of bromine at a drop rate of 0.1 m L min-1 and four volumes of acetic acid at-5℃ for three hours, the yield of guaiazulene-2,9-dione was 23.72%. This was the first report concerning optimized one-step synthesis to provide a convenient method for the large preparation of guaiazulene-2,9-dione.展开更多
The first hyperpolarizabilities of a series of novel azulenic-barbituric acid chromophores have been studied by using 12 excitation wavelengths, ranging from 900 to 1907 nm. The dispersion relation of the first hyperp...The first hyperpolarizabilities of a series of novel azulenic-barbituric acid chromophores have been studied by using 12 excitation wavelengths, ranging from 900 to 1907 nm. The dispersion relation of the first hyperpolariza-bilities of chromophores holds the same tendency as the experimental results. In addition, the static first hyperpo-larizability 0 of molecules was calculated by means of the Sum-Over-States (SOS) expression and the two-level formula respectively. The results show that these molecules possess large static first hyperpolarizabilities and the 0 value increases as the donor or acceptor strength enhances; the distorted degree of molecules has also an important influence on the 0 value.展开更多
基金supported by National Natural Science Foundation of China (No. 21102136)Changjiang Scholars and Innovative Research Team in University (PCSIRT,No. IRT0944)
文摘We previously isolated a natural product, namely guaiazulene-2,9-dione showing strong antibacterial activity against Vibrio anguillarum, from a gorgonian Muriceides collaris collected in South China Sea. In this experiment, guaiazulene-2,9-dione was quantitatively synthesized with an optimized one-step bromine oxidation method using guaiazulene as the raw material. The key reaction condition including reaction time and temperature, drop rate of bromine, concentration of aqueous THF solution, respective molar ratio of guaiazulene to bromine and acetic acid, and concentration of guaiazulene in aqueous THF solution, were investigated individually at five levels each for optimization. Combined with the verification test to show the absolute yield of each optimization step, the final optimal condition was determined as: when a solution of 0.025 mmol m L-1 guaiazulene in 80% aqueous THF was treated with four volumes of bromine at a drop rate of 0.1 m L min-1 and four volumes of acetic acid at-5℃ for three hours, the yield of guaiazulene-2,9-dione was 23.72%. This was the first report concerning optimized one-step synthesis to provide a convenient method for the large preparation of guaiazulene-2,9-dione.
基金the National Natural Science Foundation of China (Nos. 20273023 and 90101026) and the Kay Laboratory for Supramolecular Structure and Material of Ji
文摘The first hyperpolarizabilities of a series of novel azulenic-barbituric acid chromophores have been studied by using 12 excitation wavelengths, ranging from 900 to 1907 nm. The dispersion relation of the first hyperpolariza-bilities of chromophores holds the same tendency as the experimental results. In addition, the static first hyperpo-larizability 0 of molecules was calculated by means of the Sum-Over-States (SOS) expression and the two-level formula respectively. The results show that these molecules possess large static first hyperpolarizabilities and the 0 value increases as the donor or acceptor strength enhances; the distorted degree of molecules has also an important influence on the 0 value.
