鼠尾草(Salvia officinalis L.)不同组织精油组分差异比较

利用甲基叔丁醚法结合气相色谱-质谱联用技术比较鼠尾草花、叶片及茎精油的挥发性组分差异。结果表明:鼠尾草不同器官中共检测到4种单萜、17种倍半萜、6种单萜衍生物、2种倍半萜衍生物及2种酯类化合物共31种挥发性物质;不同器官的挥发性组分不尽相同,花器官中的挥发性组分最多为31种化合物;挥发性物质含量最高的是叶片,达到2 334.48 ng/g;吉玛烯、可巴烯、石竹烯及乙酸芳樟酯是鼠尾草不同器官中含量较高的挥发性组分,但其对不同器官挥发性精油的贡献率亦不同。     

Synergies between plant antioxidant blends in preventing peroxidation reactions in model and food oil systems

A study was conducted to investigate the oxidative behavior of various mixtures of rosemary, sage, and citric acid in a linoleic acid model system by oxygen consumption measurement and in a palm olein system by differential scanning calorimetry (DSC) analysis. Response surface methodology was used to optimize the use of the mixtures. Results showed that rosemary and sage were two important factors for the protective index (PI). The two antioxidants were highly significantly (P<0.001) in influencing PI values. There was a significant (P<0.01) synergistic effect between rosemary and sage on PI values. Citric acid was also found to be significant (P<0.05) for PI. With respect to onset time (T _o ), all three antioxidants were significant (P<0.05). However, no significant interaction among antioxidants was found for T _o . Mathematical models for both PI and T _o could be developed with confidence. The R ² values for PI and T _o were 0.992 and 0.926, respectively. A combination of 0.078% rosemary, 0.067% sage and 0.037% citric acid was the optimal combination for PI, whereas a combination of 0.068% rosemary, 0.075% sage, and 0.039% citric acid was required to reach the optimal T _o value.     

一串红色素的提取及其稳定性研究

研究了一串红色素的提取原理和方法,并对该色素的稳定性进行了验证。结果表明：该色素在酸性条件下对热、光均具有良好的稳定性,具有开发应用价值。     

A case study in automated theorem proving: Finding sages in combinatory logic

We present in this article an application of automated theorem proving to a study of a theorem in combinatory logic. The theorem states: the strong fixed point property is satisfied in a system that contains the B and W combinators. The theorem can be stated in terms of Smullyan's forests of birds: a sage exists in a forest that contains a bluebird and a warbler. Proofs of the theorem construct sages from B and W. Prior to the study, one sage, discovered by Statman, was known to exist. During the study, with much assistance from two automated theorem-proving programs, four new sages were discovered. The study was conducted from a syntactic point of view because the authors know very little about combinatory logic. The uses of the automated theorem-proving programs are described in detail.This work was supported by the Applied Mathematical Sciences subprogram of the office of Energy Research, U.S. Department of Energy, under contract W-31-109-Eng-38.     

Antioxidative activity and phenolic composition of pilot-plant and commercial extracts of sage and rosemary

Eight sage (Salvia officinalis) and twenty-four rosemary (Rosmarinus officinalis) extracts, originating from pilot-plant or commercial sources, had different antioxidative activities as measured by accelerated autoxidation of methyl linoleate. Twenty-seven compounds were characterized in the Labiatae family extracts by high-performance liquid chromatography (HPLC) coupled with mass spectrometry, equipped with an atmospheric pressure chemical ionization interface, and by HPLC coupled with a photodiode array spectrophotometer. Twenty-two compounds were identified, including phenolic acids, carnosol derivatives, and flavonoids. The extracts showed great variation in their HPLC profiles, and no correlation was apparent between their antioxidative efficiency and their composition, in twenty specific phenols. Data indicated that the most effective compounds were carnosol, rosmarinic acid, and carnosic acid, followed by caffeic acid, rosmanol, rosmadial, genkwanin, and cirsimaritin.     

电阻阵列冷却用脉管制冷机研制

为解决以电阻阵列器件为基础的动态红外景像产生器中的冷却问题,设计并研制了一台采用线性压缩机驱动的在223 K工作的脉管制冷机。实验结果表明:在500 W的电输入功下,制冷机的最低无负荷制冷温度为99.7 K,在232.8 K获得了181.3 W的制冷量,与理论预测制冷量189.4 W吻合良好,相对卡诺效率达到10.4%,工作对脉管制冷机在普冷温区的应用是一次有益的探索。     

Thermal recovery of antioxidant activity from carnosol quinone,the main antioxidation product of carnosol

The antioxidant reaction of carnosol, a phenolic diterpene of sage and rosemary, produced ortho‐ and para‐quinone derivatives. Although the orthoquinone derivative of carnosol (CARQ) is stable in a lipophilic solution and has a very weak antioxidant activity, the thermal treatment of CARQ in lipid restored strong antioxidant activity. HPLC analysis of the thermal recovery reaction clarified that the strong activity was mainly due to the reproduced carnosol. A possible mechanism for the production of carnosol from CARQ is the self‐redox reaction of CARQ. Two of the oxidation products from CARQ in the thermal recovery reaction were identified to be rosmariquinone and dehydrorosmariquinone. Copyright © 2004 Society of Chemical Industry