Analysis of Volatile Components in Fresh Fruit of Morinda citrifolia L.from Different Origins Based on HS-SPME-GC/MS

[Objectives]This study was conducted to clarify the differences of volatile components in fresh fruit of Morinda citrifolia L.from different origins.[Methods]The method of HS-SPME-GC/MS detection was used to determine the volatile chemical components in fresh fruit of M.citrifolia.[Results]52,52 and 45 volatile components were identified from the fresh fruit of M.citrifolia from Xisha,Wanning and Haikou,respectively.Among them,the number and content of the identified esters were relatively high,mainly methyl caprylate,ethyl caprylate,4-pentenyl caproate,3-methylbuten-2-enyl caprylate,methyl caproate,and ethyl caproate.There were also fatty acids,alcohols,phenols,ketones,aldehydes and other substances.There were 33 common ingredients in the fruit from the three origins,mainly including caprylic acid,caproic acid,capric acid,methyl caprylate,ethyl caprylate,4-pentenyl caproate,3-methylbutene-2-enyl caprylate,methyl caproate,ethyl caproate,methyl caprate and hexyl caproate.[Conclusions]The types and contents of volatile components in fresh fruit of M.citrifolia from different origins were significantly different.

Development and Processing of Millettia speciosa Instant Tea

This paper analyzed the effect of raw material crushing fineness,cooking time,ethanol content during ethanol precipitation and other factors on the preparation of raw material extract from Millettia speciosa Champ. instant tea. The raw materials of Millettia speciosa Champ.,Philippine flemingia root and radix fici simplicissimae were crushed into 10 mesh or finer powder,and cooked for 60 min. During ethanol precipitation,the ethanol content was about 50% to 70%,standing 12 h. The ophiopogon root was cooked in 1∶ 15 boiling water for 45 min,and chrysanthemum was leached for 45 min with 1∶ 20 demineralized water at 80 ℃. After concentration,preparation and spray drying,the finished Millettia speciosa Champ. instant tea was created. The detection of each product index indicated that Millettia speciosa Champ. instant tea had good taste and flavor,and there were no heavy metals,harmful substances and excessive microbes,thereby showing that the raw material of Millettia speciosa Champ. instant tea was selected reasonably,the mixture ratio was rational,and the processing technology was of some security,stability and maturity,which provided a theoretical basis for its development and application.

GC-MS Analysis of Liposoluble Constituents from Buds,Flowers and Fruits of Millettia speciosa Champ.

[Objectives] To study the material foundation of liposoluble constituents from buds,flowers and fruits of Millettia speciosa Champ.and provide a reference for the development of flowers and fruits of Millettia speciosa Champ.[Methods]The liposoluble constituents were extracted from buds,flowers and fruits of Millettia speciosa by Soxhlet extraction and solvent extraction method,and analyzed by GC-MS.[Results]24 compounds were identified from the liposoluble constituents of buds,accounting for 88. 31 % of the total liposoluble constituents,mainly comprising alkanes and olefins compounds( 52. 00%) and alcohols compounds( 17. 46%); 29 compounds were identified from the liposoluble constituents of flowers,accounting for 91. 38 % of the total liposoluble constituents,mainly comprising alkanes and olefins compounds( 60. 64%) and alcohols compounds( 17. 17%); 32 compounds were identified from the liposoluble constituents of fruits,accounting for 80. 01 % of the total liposoluble constituents,mainly comprising alkanes and olefins compounds( 32. 56%),phenyl and its derivatives compounds( 22. 46%) and fatty acids compounds( 12. 54%). 6 compounds were common in buds,flowers and fruits. [Conclusions] Although there were some differences in liposoluble constituents from flowers,fruits,leaves and roots of Millettia speciosa Champ.,the different parts of Millettia speciosa Champ. had development value.

Effects of Different Herbicides on the Control of Malachium aquaticum L. and Poa annua L.

In this experiment,the effects of 13 kinds of herbicides( or mixtures) on the control of two kinds of weeds were studied by pot cultivation with the broadleaf weed Malachium aquaticum L. and Gramineae weed Poa annua L. as the materials. The results showed that the herbicide MCPA-Na had the best and fastest control effect on M. aquaticum L.,and all the M. aquaticum L. died 7 d after treatment;it was followed by the other four herbicides including MCPA-Na + clethodim,MCPA-Na + quizalofop-p-ethyl,bentazon and nicosulfuron·atrazine,and all the M. aquaticum L. died 14 d after treatment. Atrazine was the best herbicide to control Gramineae weeds,followed by nicosulfuron·atrazine,and mesotrione·nicosulfuron·atrazine. The study on the application of field herbicide found that four herbicides including atrazine,mesotrione·nicosulfuron·atrazine,nicosulfuron·atrazine and bentazon had better control effect on weeds. The best herbicide for flax field was MCPA-Na + clethodim,followed by MCPA-Na and MCPA-Na + quizalofop-p-ethyl. The optimized herbicides and combinations had no harmful effects on the growth of corn and flax.

Liposoluble Constituents from the Flowers of Calotropis Gigantea and Their Antimicrobial Activity

[Objectives] To study the liposoluble constituents and their antimicrobial activity from the flowers of Calotropis gigantea.[Methods]The liposoluble constituents from the flowers of Calotropis gigantea were analyzed by gas chromatography-mass spectrometry(GCMS) method and their relative content was determined by area normalization method; and their antimicrobial activity against 2 pathogens was tested by agar disc diffusion method. [Results]31 compounds were separated and identified,amounting to 85. 14% of the total constituents,27 compounds were reported for the first time in the study of the liposoluble constituents from Calotropis gigantea. The results indicated that the liposoluble constituents from the flowers of Calotropis gigantea exhibited weak antimicrobial activity against Staphylococcus aureus and Canidia albicans. [Conclusions] The research results provided scientific foundation for exploitation and utilization of Calotropis gigantea.

GC-MS Analysis of Liposoluble Constituents from Calotropis gigantea Roots

[Objectives] To effectively develop Calotropis gigantea resources and find the biological active constituents with medicinal value.[Methods]The liposoluble constituents from C. gigantea roots were studied by GC-MS for the first time. [Results] 62 constituents were separated and identified from C. gigantea roots,amounting to 60. 43% of the total constituents,α-amyrin( 4. 18%),ethyl palmitate( 3. 49%),1,7-dimethyl-naphthalene( 3. 06%) were the main liposoluble constituents. [Conclusions] Cardiac glycoside was mainly found in methanol extracts and not detected in liposoluble constituents by extraction of petroleum ether. However,the present study found another component of low toxicity—naphthalene and its derivatives.

量子自旋霍尔绝缘体Bi_(4)Br_(4)体与边缘的可区分的光学性质研究

量子自旋霍尔绝缘体拥有具有带隙的体态和无能隙的一维拓扑边缘态.然而,由于拓扑边缘态局域在纳米尺度,所以很难用光学手段直接观测并区分体态和边缘态,这就限制了对拓扑边缘态独特的光学特性和光电响应等方面的研究和应用.Bi_(4)Br_(4)体材料的台阶存在一维非平庸的边缘态,多个台阶累加的效应使得通过较为宏观的光学和光电分析手段来研究一维边缘态成为可能.该工作利用中远红外显微吸收光谱和泵浦探测光谱,对比研究了Bi_(4)Br_(4)体和边缘的光学响应行为.研究发现Bi_(4)Br_(4)的边缘在小于带隙(约0.22 eV)的波段存在明显的强于体内的红外吸收,且该吸收呈现较强的各向异性.室温下的红外泵浦探测首次观察到边缘处载流子激发态超长的弛豫时间(1.5 ns),该激发态载流子寿命要比体内载流子寿命长两个量级.该工作证实体态和拓扑边缘态具有明显不同的光学和光电响应行为,为未来设计新型红外探测器提供了材料和物理基础.