【作者】 陈丛瑾；

【导师】 黄克瀛； 李德良；

【作者基本信息】 中南林业科技大学 ， 林产化学加工工程， 2010， 博士

【摘要】 以有效综合利用香椿资源为出发点,比较研究了香椿芽挥发油的提取方法,香椿芽、叶的挥发性成分的快速检测方法,不同产地、月份、不同部位香椿油的成分和活性；结合香椿叶提取物不同极性成分群的活性跟踪分析了乙酸乙酯部位的部分化学成分；测定了香椿的微量元素；比较研究了香椿叶总黄酮的测定、提取、纯化方法；研究了香椿芽挥发油和总黄酮的联合提取方法等。主要研究结果如下：(1)采用超临界C02萃取、超声波辅助乙醚萃取、微波辅助乙醚萃取微波水蒸气蒸馏4种方法提取香椿芽挥发油并用气相色谱-质谱(GC-MS)方法分析比较其化学成分时,各萃取方法得到的挥发油的得率、外观和化学组成存在差异：其中,超临界流体C02萃取精油得率最高(13.3 mL·kg-1),颜色和香味仅次于微波水蒸气蒸馏萃取法(得率3.1 mL·kg-1)。(2)用顶空微固相萃取(HS-SPME)/GC-MS法分析比较了香椿芽和香椿叶的挥发性化学成分,从香椿芽、叶中分别鉴定出26和46个成分,占各自挥发性组分总质量的74.86%和91.20%(质量分数,下同),主要成分都是β-石竹烯,分别为10.12%和46.87%。该法用于香椿挥发性化学成分检测,方便快捷。(3)用同时蒸馏萃取(SDE)/GC-MS法分析比较了不同产地、月份香椿叶片精油,不同产地、月份香椿叶轴精油,同一产地、月份、不同部位香椿精油；发现精油的提取率都不同,其中广西南丹8月产香椿叶片精油提取率最高,为7.33 mL·kg-1；所得精油的化学组成也存在差异,但都以倍半萜类化合物为主要组分。(4)用水蒸气蒸馏(HD)/GC-MS法分析比较了广西南宁11月产香椿叶片、叶轴和香椿皮挥发性物质的化学组成。结果它们的化学组成存在差异,但都含有9种相同的化合物(主要是倍半萜含氧化合物),且各组分的含量有差异(5)在活性跟踪的指导下对香椿叶提取物的乙酸乙酯部位进行了分离纯化,通过常压硅胶柱层析,重结晶,葡聚糖凝胶SephadexLH-20柱层析等方法,分离得到7个化合物。运用化学定性,IR、UV、LC-ESI-MS、1H-NMR、13C－NMR波谱解析和与文献对照等方法,鉴定它们分别是东莨菪素(Ⅰ),山柰酚(Ⅱ),没食子酸乙酯(Ⅲ),槲皮素(Ⅳ),没食子酸(Ⅴ),芦丁(Ⅵ),槲皮素-3-O-α-L鼠李糖苷(Ⅶ)。(6)用电感耦合等离子体原子发射光谱法(ICP－AES法)同时测定不同月份香椿不同部位中的Fe、Mn、Cu、Zn、Ca、Mg、Na、K、Al、Pb、Cd、和Ni 12种元素的含量,方法的加标回收率为93.6%～109.0%,相对标准偏差RSD为0.51%～4.87%。该法测定结果表明香椿中含有丰富的Ca、Mg、Fe、Zn和K等元素,Na、Mn、Cu的含量也相对丰富,且各元素的含量随月份及部位变化而变化。(7)建立了香椿叶总黄酮含量的AlCl3显色分光光度法和NaNO2-Al(NO3)3显色分光光度法的测定方法,结果是前者更适合测定香椿叶提取物黄酮含量。(8)建立了香椿叶提取物清除DPPH·能力的测定方法,提出以IM50值来评价抗氧化剂的自由基清除能力,IM50的物理意义为：当DPPH·达到50%清除率时,单位质量抗氧化剂所清除DPPH·的质量(9)以总黄酮提取率和清除DPPH·的IM50为指标,研究、比较了香椿叶总黄酮的超临界CO2提取、微波辅助提取、超声波辅助提取、酶法辅助提取、半仿生法提取和常规溶剂回流提取六种工艺条件。发现微波法优于酶法,微波法高效、省时,特别适用于香椿叶总黄酮的提取；酶法条件温和,效果较好,提取率高,也适用于提取香椿叶总黄酮。超声提取法和常规溶剂回流法(效果相差小)都次于微波法和酶法,尚可用于提取香椿叶总黄酮；而超临界CO2提取、半仿生提取法总黄酮提取率低,不适合提取香椿叶总黄酮。优化的微波法和酶法提取工艺条件如下：微波辅助提取工艺条件：香椿叶粉20 g,以料液比1：12(g·mL-1)加入φ(C2H5OH)=70%的乙醇溶液,在磁力搅拌转速1000 r·min-1,80℃下每次提取20 min,提取4次,总黄酮提取率为99.08%,提取物以总黄酮计的清除DPPH·的IM50值为37.107 3g DPPH··g-1黄酮。酶法辅助提取工艺条件是：25 g香椿叶粉、175 mg纤维素酶和200 mL pH值为4.0的HAc-NaAc缓冲液混匀后,在150 r·min-1的摇床中,50℃下酶解2 h后,加入400 mLφ(C2H5OH)=95%的乙醇在70℃浸提1h,过滤,滤渣加入400 mLφ(C2H5OH)=65%乙醇溶液提取,每次1h,共提取5次,总黄酮提取率为95.00%,提取物以总黄酮计的清除DPPH·的IM50值为28.0907g DPPH··g-1黄酮。(10)采用超临界和微波联合提取香椿芽有效成分时,超临界CO2萃取香椿油的得率为13.3 mL.kg-1,芽渣微波提取总黄酮的最佳工艺条件：溶剂乙醇溶液浓度φ=50%,1g香椿芽渣用溶剂12mL,提取温度70℃,每次提取时间15min,提取3至4次。在此条件下1g香椿芽渣可提取总黄酮65.1140 mg至72.9344 mg。(11)研究、比较了X-5树脂纯化、聚乙二醇-硫酸铵双水相富集分离、超滤纯化香椿提取液总黄酮的工艺条件。结果前2种方法效果较好；SCM300杯式超滤器超滤浓缩、纯化香椿提取液黄酮效果不明显。较好纯化方法的工艺条件如下：X-5树脂分离纯化较佳工艺条件为,吸附：室温,流速3 BV/h,溶液处理量6 BV/次,上柱液pH值在5-6；脱附：脱附剂为φ(C2H5OH)=70％乙醇溶液,流速3 BV/h,脱附剂用量6 BV/次。在此条件下,树脂使用1次时,总黄酮的收率达95.5%,总黄酮的纯度由7.2%提高到43.5%；树脂重复使用5次时,总黄酮的收率仍达80%以上,总黄酮的纯度可由7.2%提高到20%以上。聚乙二醇-硫酸铵双水相萃取的适宜工艺条件为：在8 mL黄酮浓缩液中,加入2.5 g聚乙二醇,2.5 g硫酸铵,在自然pH值(5.35),不断振摇下40℃分相3 h。在此条件下,浓缩液的黄酮浓度从3238.011 mg-1提高到4024.036 mg·L-1(上相),总黄酮的收率达99.92%,分配系数为1406.564。(12)采用管碟法测得香椿叶提取物不同极性部位对大肠杆菌、枯草芽孢杆菌具有一定的抑制作用,对青霉和油茶炭疽菌的抑菌活性小。乙酸乙酯部位对大肠杆菌和枯草芽孢杆菌的活性最强,最低抑菌浓度(MIC)分别为0.3 mg.mL-1和0.6 mg.mL-1,最低杀菌浓度(MBC)都为0.6 mg.mL-1。其次是S-8树脂吸附部位,MIC和MBC都为0.8 mg.mL-1。正丁醇部位抑制青霉和油茶炭疽菌的活性最强,MIC和MB C都为7.1 mg.mL-1。采用喷雾法和浸虫法测试香椿叶提取物及其不同极性溶剂萃取部位在总固物浓度为10 mg.mL-1时对小菜蛾、斜纹夜蛾和烟蚜的杀虫活性低。不同极性部位对小菜蛾3龄幼虫在72 h内没有杀虫效果；叶片提取物乙酸乙酯部位对斜纹夜蛾2龄幼虫杀虫活性最高,处理72 h后死亡率为44%；叶片提取物正丁醇部位对烟蚜无翅孤雌成蚜杀虫活性最高,处理48 h后死亡率为23.6%。采用分光光度法测得香椿叶提取物及其不同极性萃取部位都有一定的DPPH·的清除能力,但能力不同。香椿叶片和叶轴都是乙酸乙酯部位对DPPH·的清除能力最强,其次是90%乙醇提取物,再其次是正丁醇部位,且这三个部位都是叶轴对DPPH·的清除能力比叶片强。(13)采用管碟法测得广西南丹和东南8月产香椿叶片、广西东南8月产叶轴精油对大肠杆菌、枯草芽孢杆菌、青霉、油茶炭疽菌都具有显著的抑制作用,对供试细菌的抑菌圈直径为26 mm-60 mm,对供试真菌的抑菌圈直径为11 mm-50 mm。香椿叶3个油样对大肠杆菌、枯草芽孢杆菌的MIC和MBC都小于0.03125%,对青霉的MIC都为0.2500%,MBC都为0.5000%,对油茶炭疽菌的MIC都为0.06250%,MBC都为0.2500%。香椿精油对DPPH·的清除能力弱。更多还原

【Abstract】 In order to utilize effectively nature source of Toona sinensis (A.Juss.) Roem leaves, extraction methods of volatile oil from Toona sinensis sprouts and rapid determination of volatile compounds in Toona sinensis sprouts and leaves were studied. The essential oil components and their activities of different parts, producing areaes and seasons of Toona sinensis were studied; the chemical composition of the ethyl acetate extracts was isolated and identified by tracking the activitives of different polar fractions of Toona sinensis leaf extracts. Trace elements from Toona sinensis were determined. The different determination, extraction and purification methods of total flavonoids in Toona sinensis leaves were compared. Combined extracting methods of Toona sinensis sprouts volatile oil and total flavonoids were studied. The main results were as follows:(1) Supercritical CO2 extraction, ultrasonic-assisted extraction with ether, microwave-assisted extraction with ether and microwave-water vapour distillation were employed to extract the volatile oil from Toona sinensis sprouts and its compositions were analyzed by gas chromatography-mass spectrometry(GC-MS). Results showed that the chemical compositions, yield, appearance of volatile oil were extacted by four methods are different; the yield of essential oils extracted by supercritical fluid CO2 is the highest (13.3 mL·kg-1), and the color and fragrance of the oil is only inferior to that of essential oils extracted by microwave distillation extraction (yield 3.1 mL·kg-1).(2) The volatile compounds from Toona sinensis sprouts and leaves were analyzed by headspace-solid phase microextraction(HS-SPME) /GC-MS,26 and 46 kinds volatile compounds were identified and accounted for 74.86% and 91.20% of total volatile compounds, respectively (mass fraction, same as below), the major volatile compound from sprouts and leaves isβ-Caryophyllene, which accounts for 10.12% and 46.87%, respectively. HS-SPME/GC-MS is a simple, time-saving and solvent-free method, and it is a potential analytic tool for the determination of the volatile compounds of Toona sinensis.(3) Essential oils were extracted from different parts of Toona sinensis, Toona sinensis leaves in different sensons and different producing areaes by simultaneous distillation extraction (SDE)/GC-MS method were studied. The results showed that the yield of essential oil is different, The yield from Guangxi Nandan in August is the highest (7.33 mL·kg-1); the chemical compositions of all essential oils are different, but the main components are sesquiterpenoids.(4) Essential oils were extracted from Toona sinensis leaves, leaf axis and bark grown in Nanning, Guangxi in November by steam distillation (HD) and the volatile comounds were identified by GC-MS. The results showed that the chemical compositions of essential oil are different, however each kinds of essential oil contains nine kinds same compounds (sesquiterpenes oxide), but each content is different.(5) According to the results of tracking the activitives of different polar fractions of Toona sinensis leaf extracts, the ethyl acetate extracts were selected to isolate and purify chemical composition. Seven compounds were obtained by isolated and purified through normal pressure silica gel, SephadexLH-20 column chromatography and recrystallization. The structures of these compounds were elucidated by spectroscopic methods (including IR, UV, LC-ESI-MS,1H-NMR,13C-NMR) and compared with reported data. They were identified as scopoletin (1), kaempferol (2), ethyl gallate (3), quercetin (4), gallic acid (5), rutin (6), quercetin-3-O-α-L rhamnoside (7), respectively.(6) A method for the simultaneous determination of elements Fe, Mn, Cu, Zn, Ca, Mg, Na, K, Al, Pb, Cd, and Ni in Toona sinensis (A Juss.) Roem by ICP-AES was studied. The results showed that Toona sinensis (A Juss.) Roem is rich in Ca, Mg, Fe, Zn and relatively rich in K, Na, Mn, Cu, and the elements content changes with seasons and the parts in plants.(7) AICI3 spectrophotometric method and NaNO2-Al(NO3)3 spectrophotometric method for determination of flavonoids in the extracts of Toona sinensis leaves (FETs) were established and compared, the results showed that the former is more suitable for determination of flavonoids content of Toona sinensis leaf extracts.(8) A spectrophotomctric method was determined for determining 2,2-Diphenyl-1-picrylhydrazyl (DPPH·) scavenging activity of Toona sinensis leaves extracts. The evaluating criterion of DPPH·scavenging activity is regarded as "IM50", its physical meaning is:the DPPH·quality removed by the unit mass extracts when DPPH·scavenging rate is 50%.(9) Supercritical CO2 extraction, microwave-assisted extraction, ultrasound-assisted extraction, enzyme-assisted extraction, semi-bionic extraction, conventional solvent extraction, these six process conditions were studied and compared by extractive yield and IM50 of scavenging DPPH·of total flavonoids as index. Results showed that: microwave-assisted extraction is the best, it is efficient, saving time, especially suitable for extraction of Toona sinensis leaf flavonoids(ETsF). Enzyme-assisted extraction is the second. Mild with high extraction yield, it is also suitable for ETsF. Ultrasound-assisted extraction and conventional solvent extraction(there are little difference between their effects) are inferior to microwave-assisted extraction and enzyme-assisted extraction, but still could be used to ETsF. While extraction yield of supercritical carbon dioxide extraction and semi-bionic extraction is small, these two methods are unsuitable for ETsF. Optimization extraction process of the microwave-assisted extraction and enzyme-assisted extraction are determined as follows:Microwave-assisted extraction process is:temperature 80℃, each extraction time 20 min,70% EtOH as extracting solvent, stock ratio 1:12 (g·mL-1, mass:volume), microwave extracting for four times. The extractive yield is 99.08%. IM50 of scavenging DPPH·of total flavonoid is 37.1073 g DPPH··g-1 flavonoids.Enzyme-assisted extraction process is:enzyme dosage 7 mg·g-1 Toona sinensis leaves, enzymatic hydrolysis temperature 50℃, enzymatic hydrolysis time 2 h, enzymatic hydrolysis pH=4.0, extracting temperature 80℃, each extraction time 1 h,65% EtOH as extracting solvent, stock ratio 1:8 (g·mL-1, mass:volume), extracting for five times, the extractive yield was 95.00%, IM50 of scavenging DPPH·of total flavonoid was 28.0907 g DPPH··g-1 flavonoids.(10) Toona sinensis sprouts were extracted by supercritical CO2 to get volatile oil (yield 13.3 mL·kg-1) and then microwave was used to extract total flavonoids. The optimum conditions are:extraction temperature 70℃, ethanol volume (used to extract 1 g Toona sinensis sprouts) 12 mL,50% ethanol as extraction solvent, each extraction time 15 min and microwave extraction for three to four times. The mass of total flavonoids extracted from Toona sinensis sprouts is 65.1140 mg·g-1 to 72.9344 mg·g-1.(11) X-5 macroporous resin adsorption, polyethylene glycol ammonium sulfate aqueous two-phase extraction, ultrafiltration, three purification process conditions were studied and compared, results showed that:the former two motheds workes well, but SCM300 cup ultrafilter’s ultrafiltration, purification has little effects. The results of better purification process showed as follows:X-5 resin separation and purification process conditions are: adsorption:temperature 15℃or so, flowing speed 3 BV/h, solution treatment capacity 6 BV, pH value 5-6. Desorption:total flavonoids adsorbted can be desorbed by 70% alcohol at flowing speed 3 BV/h, dosage 6 BV. Compared to the 7.2% of total flavonoids in crude extracts, the recovery and purity of total flavonoids are 95.5% and 43.5%, respectively. when the fresh resin is used. The recovery and purity of total flavonoids are over 80% and 20%, respectively when the resin is used five times.Polyethylene glycol ammonium sulfate aqueous two-phase extraction for enrichment and separation purification process conditions are:2.5 g PEG (MW600) and 2.5 g ammonium sulfate are added to 8 mL crude extracts, the contents are mixed thoroughly by shaking at 40℃and pH value 5.35 (the inherent pH of extracts system) for equilibration and are allowed for phase separation for 3 h. On the above-mentioned appropriate conditions, the crude extracts flavonoids concentration is enhanced from 3238.011 mg·L-1 to 4024.036 mg·L-1 in top phase, the flavonoids yield reaches 99.92%, the distribution coefficient was 1406.564.(12) Different polar fractions of ethanol (φ=90%) extracts from Toona sinensis leaves and leaf axis exhibit certain growth inhibitory activity against bacteria Escherichia coli and Bacillus subtilis, but has weak growth inhibitory activity against fungi Penicillium citrinum and Colletotrichum gloeosporioides. Among them, ethyl acetate fractions show the strongest antibacterial activity with the minimal inhibitory concentration(MIC) and the minimal bactericidal concentration(MBC) for Escherichia coli 0.3 mg·mL-1 (MIC),0.6 mg·mL-1 (MBC) and for Bacillus subtilis 0.6 mg·mL-1 (MIC),0.6 mg·mL-1 (MBC). S-8 fractions exhibit the second strongest antibacterial activity against bacteria Escherichia coli and Bacillus subtilis, MIC and MBC are both 0.8 mg·mL-1. N-butanol fractions show the most remarkable activity against fungi Penicillium citrinum and Colletotrichum gloeosporioides, MIC and MBC are both 7.1 mg·mL-1.Different polar fractions of ethanol (φ=90%) extracts from Toona sinensis leaves and leaf axis were used to test insecticidal activity against Plutella xylostella L., Spodoptera litura Fab. and Myzus persicae(Sulzer) when the total solid concentration was 10 mg·mL-1 by spray method and dipping method. Results showed that all fractions exhibited weak insecticidal activity against tested insects. All fractions have no insecticidal effect against Plutella xylostella L.; ethyl acetate fraction of leaves show the strongest insecticidal activitiy against Spodoptera litura Fab. with the mortality rate 44% after treated 72 hours; n-butanol fractions of leaves showes the strongest insecticidal activity against Myzus persicae(Sulzer) with the mortality rate 23.6% after treated 48 hours.Toona sinensis leaf or leaf axis extracts and different polar fractions exhibit DPPH·scavenging activity, but they are different. Ethyl acetate extraction fractions of Toona sinensis leaves and leaf-axis show the strongest DPPH·scavenging activity, followed by 90% ethanol extracts, and then followed by n-butanol extraction fractions. DPPH·scavenging activity of these three extraction fractions from the leaf axis are stronger than that from the leaves. (13) Essential oils of Toona sinensis leaves from Guangxi Nandan and Dongnan in August, essential oils of Toona sinensis leaf axis from Guangxi Dongnan in August exhibit significant antibacterial activity against bacteria Escherichia coli and Bacillus subtilis and fungi Penicillium citrinum and Colletotrichum gloeosporioides. The diameter of inhibition zone of essential oils are 26 mm-60 mm against bacteria and 11 mm-50 mm against fungi. MIC and MBC against Escherichia coli and Bacillus subtilis are less than 0.03125%; MIC and MBC against Penicillium citrinum is 0.2500% and 0.5000%; MIC and MBC against Colletotrichum gloeosporioides. is 0.06250% and 0.2500% for all essential oils samples.Essential oils from Toona sinensis leaves exhibit weak DPPH·scavenging activity.更多还原