【作者】 彭红明；

【导师】 彭镇华；

【作者基本信息】 中国林业科学研究院 ， 园林植物与观赏园艺， 2009， 博士

【摘要】 本研究围绕中国兰花挥发性物质中主要及特征花香成分确定,以中国兰花蕙兰、建兰、寒兰和春兰等,以及热带兰之蝴蝶兰、长萼兰等为研究对象,应用气相色谱-质谱联用(GC/MS)的方法对兰花花香挥发性成分进行了定性和相对定量分析。筛选建立了适合兰花香气成分分析的采样收集方法;通过分析比较国兰代表种之间,以及与几种热带兰的挥发性成分差异,初步确定了国兰的特征香气成分;同时,分析和比较了萃取时间、萃取温度,以及不同花期、花色对兰花挥发性成分测定的影响和组成的差异。研究主要内容和获得结果如下:1、针对兰花花香强度和挥发特点,通过试验比较了顶空固相微萃取(SPME)、动态顶空密闭循环式吸附(TCT)以及吹扫捕集(P&T)三种收集方法,确定了以顶空固相微萃取法(SPME)为主,动态顶空密闭循环式吸附法(TCT)法为辅的有效的兰花挥发性成分收集方法。比较分析了不同萃取头,不同萃取时间对兰花香气成分分析的影响。确定了100μmPDMS萃取头、萃取60min是最佳分析条件。2、分析比较国兰之间以及国兰与热带兰挥发性成分的区别。经多种材料的固相微萃取分析测定,常温下,国兰种类中共检测到99种挥发性成分,其中酯类物质相对百分含量较高;热带兰共检测到113种挥发性成分,其中萜烯类物质种类丰富,含量较高。重要的是,国兰挥发性成分中茉莉酸甲酯、3-氧代-2-(2-戊炔基)-环戊基乙酸甲酯、酯类物质C普遍存在且含量较高,但在热带兰中未检测到同类物质。上述酯类物质在国兰的普遍存在以及与热带兰的显著差异提示我们,酯类物质是决定国兰与热带兰香气差异的主要或重要因素,可能是中国兰花的特征香气成分。3、野生种群中蕙兰、寒兰花色上存在明显差别。蕙兰有绿蕙兰、黄紫蕙兰、黄绿蕙兰、紫蕙兰等;寒兰有绿寒兰、紫寒兰等。本研究初步分析比较了同种不同花色中国兰花的挥发性成分。1)SPME-GC/MS分析常温下开放的黄紫蕙兰、绿蕙兰挥发性成分组成。黄紫蕙兰检测到25种化合物,绿蕙兰检测到23种化合物。其中共有组分17种,黄紫蕙兰特有组分8种,绿蕙兰特有组分6种。两种蕙兰主要挥发性成分差异不大,但黄紫蕙兰增加了罗勒烯与香叶基丙酮,绿蕙兰中增加了Z,Z,Z-1,4,6,9-十九碳四烯和2,5-十八碳二炔酸甲酯。2)TCT- GC/MS分析四种不同花色蕙兰挥发性成分的组成。黄紫蕙兰共检测到内三环[5,2,1,0(2,6)]癸烷、茉莉酸甲酯A、茉莉酸甲酯B、金合欢醇、2-丙基戊醇等48种化合物。绿蕙兰共检测到金合欢醇、茉莉酸甲酯B、内三环[5,2,1,0(2,6)]癸烷、罗勒烯、异佛尔酮、2-丙基戊醇等40种化合物;黄绿蕙兰检测到异佛尔酮、3-氧代-2-(2-戊炔基)-环戊基乙酸甲酯、金合欢醇、茉莉酸甲酯B等31种化合物;紫蕙兰共检测到金合欢醇、2-丙基戊醇、内三环[5,2,1,0(2,6)]癸烷、茉莉酸甲酯B、罗勒烯、芳樟醇等24种化合物;柠檬烯、长叶烯、金合欢烯等化合物在四种蕙兰中的相对含量差别较小,异佛尔酮、金合欢醇、芳樟醇、罗勒烯、茉莉酸甲酯等差别较大。3)SPME-GC/MS分析常温下不同花色寒兰的挥发性成分变化。绿寒兰共分离得到酯类物质C、茉莉酸甲酯B、2,5-十八碳二炔酸甲酯、乙酸金合欢酯等22种挥发性成分。紫寒兰中共分离得到酯类物质C、3-氧代-2-(2-戊炔基)-环戊基乙酸甲酯、乙酸金合欢酯、茉莉酸甲酯B等18种挥发性成分。绿寒兰中酯类物质种类较多,紫寒兰中酯类物质较少,挥发性组分总数也不高。绿寒兰中的2,5-十八碳二炔酸甲酯和Z,Z,Z-1,4,6,9-十九碳四烯与紫寒兰中的4,7-二甲基-4-辛醇和香叶基丙酮含量变化最大,是不同花色寒兰香气差异的主要原因。4、针对花期等因素对兰花香气释放的影响,本研究将蕙兰花期分为五个时期。利用SPME-GC/MS方法分别分析了黄紫蕙兰、绿蕙兰、建兰不同花期的挥发性成分变化;同时利用TCT-GC/MS方法分析了黄紫蕙兰挥发性成分的日变化。1)黄紫蕙兰花期结果分析显示:花蕾期主要香气成分为罗勒烯和α-金合欢烯;半开期(E、E)-金合欢醇、茉莉酸甲酯、酯类物质C为主要香气成分;盛开期(E、E)-金合欢醇的相对含量>茉莉酸甲酯>罗勒烯。盛开末期(E、E)-金合欢醇的相对含量>酯类物质C>香叶基丙酮>罗勒烯。衰败期共检出化合物10种,其中烷烃含量较大,种类最多,不存在酯类物质。罗勒烯在半开期合成释放增多;香叶基丙酮在盛开期以后合成释放增加;(E、E)-金合欢醇一直作为含量最高的成分存在香气较淡的花蕾期和盛开末期之外的其它时期,对黄紫蕙兰香气贡献较大。2)分析绿蕙兰花期结果显示:花蕾期主要香气成分反式-罗勒烯和芳樟醇;绿蕙兰半开期酯类物质C和茉莉酸甲酯的相对百分含量达70%;盛开期罗勒烯和酯类物质C的相对百分含量达60%;盛开末期金合欢醇和酯类物质C的相对百分含量达50%;衰败期共检出化合物8种,主要有壬醛、癸醛等,对花香贡献不大。试验表明罗勒烯的相对百分含量随花期变化较大,说明罗勒烯的合成、释放与花期直接相关;酯类物质C在半开、盛开、盛开末期中一直作为主要物质存在,受花期影响较少,是绿蕙兰香气的主要贡献成分。3)分析建兰花期结果显示:建兰挥发性成分总量的变化趋势为:从花蕾期开始,挥发性成分总量随时间增长而增大,第2天、第4天总量变化不大,达到最高峰,之后,挥发性成分总量开始下降。在整个花期过程中,正十五烷与桉树脑的含量几乎没有变化,表明正十五烷与桉树脑对建兰花香没有直接影响。茉莉酸甲酯B、3-氧代-2-(2-戊炔基)-环戊基乙酸甲酯等五种酯类物质从半开期出现后到开花第四天基本上呈递增趋势,之后开始下降;12-[4.4.3.0(1,6)]氧杂三环十三烷-3,11-二酮、Z,Z,Z-1,4,6,9-十九碳四烯也是建兰主要挥发性物质,这三种物质在开花第二天达到含量最高峰,之后呈递减趋势。4)分析蕙兰挥发性日变化得出:醇类物质在下午3时的挥发量较高;酯类物质在上午11时左右的挥发量较高。茉莉酸甲酯的两种同分异构体A、B,茉莉酸甲酯A上午的挥发量要高于下午,茉莉酸甲酯B则相反,但是,两种物质在全天的挥发量均较高;长叶烯的挥发性日变化不是很明显,罗勒烯的挥发量在上午约是下午的4-5倍;醛类、酮类及其它物质,在蕙兰的挥发性成分中含量相对要少,变化不显著。更多还原

【Abstract】 The main and characteristic fragrance components that defined Chinese cymbidium, C. faberi, C. ensifolium, C. Kanran, C. goeringii and tropical orchids, Phalaenopsis , Brassia and more, were studied using gas chormatography/mass spectrometry (GC/MS) method, by the qualitative and quantitative analysis.In this study, sampling methods which were suitable for analysis the fragrance components in cymbidium was screened and established. Through analysis and comparison the differences of volatile components among Chinese cymbidium representatives, and the differences between Chinese cymbidium and tropical orchid, characteristic fragrance components in Chinese cymbidium were definited preliminary. Moreover, the affects of extraction time, extraction temperature, different florescence and flower color in determining the cymbidium volatile components and the differences of components were analyzed and compared.The following conclusions were made from the above studies.1. According to the characteristics of fragrance intensity and volatility in cymbidium, three collecting methods, Solid Phase Microextraction (SPME), Thermal Desorption Cold Trap injector (TCT) and Purge and Trap(P&T), were compared by experiments, with determination of SPME being given priority to TCT as effective method collecting for volatile components of cymbidium. In this study, the affects of fibers, extraction time on analysis fragrance components of cymbidium were analyzed and compared. The optimum extraction condition was: extracting 60min by 100μmPDMS fiber.2. The differences of volatile components, among Chinese cymbidium and between Chinese cymbidium and tropical orchid, were analyzed. Through collecting, detecting diverse samples, the results showed that 99 kinds of volatile components were present in Chinese cymbidium, in which ester compounds were with high relative content. As well as 113 kinds of volatile components were detected in tropical orchid, terpenoid compounds with rich species and high relative content.It is important that methyl jasmonate, cyclopentaneacetic acid, 3-oxo-2-(2-pentynyl)-, methyl ester and compound C were widespread with high relative content in Chinese cymbidium, but they were not detected in tropical orchid. This phenomenon pointed out that ester compounds were the main or important factors which created the fragrance discrepancy between Chinese cymbidium and tropical orchid, and they may be the characteristic fragrance components.3. There are obvious difference in the flower color of populations of wild C. faberi and C. Kanran in nature. The wild C. faberi has colors in green, yellow-purple, yellow-green, purple and others. The C. Kanran has colors in green, purple and others.. In this study, the preliminary analysis and comparison were made on the volatile components of same species Chinese cymbidium with different color.1) The volatile components in yellow-purple and green flower C. faberi were analyzed by using SPME-GC/MS at normal temperature. The results showed that there were 25 components in yellow-purple C. faberi and 23 components in green C. faberi, as well as 17 components in both color flower C. faberi, 8 kinds of special components in yellow-purple C. faberi, and 6 kinds of special components in green C. faberi. There were no significant differences in the main volatile components between the two species of C. faberi., However,ocimene and geranylacetone were found more in yellow-purple C. faberi, Z,Z,Z-1,4,6,9-nonadecatetraene and methyl-2,5-octadecadiynoate were found more in green C. faberi.2) The volatile components in four different color flower C. faberi were analyzed by using TCT-GC/MS. Endo tricyclo[5,2,1,0(2,6)] decane, methyl jasmonate A, methyl jasmonate B, farnesol, 2-propyl-1-pentanol and etc, a total of 48 components were detected in yellow-purple C. faberi. Farnesol, methyl jasmonate B, endo tricyclo[5,2,1,0(2,6)] decane, ocimene, isophorone, 2-propyl-1-pentanol and etc, a total of 40 components were detected in green C. faberi. Isophorone, cyclopentaneacetic acid, 3-oxo-2-(2-pentynyl)-, methyl ester, farnesol, methyl jasmonate B and etc, a total of 31 components were detected in yellow-green C. faberi. Farnesol, 2-propyl-1-pentanol, endo tricyclo[5,2,1,0(2,6)] decane, methyl jasmonateB, ocimene, linalool and etc, a total of 24 components were detected in purple C. faberi. The differences of the relative contents of limonene, longifolene, farnesene, and others, were not obvious. On the contrary, there were obvious differences in relative contents in isophorone, farnesol, linalool, and ocimene.3) The volatile components in different color flower C. Kanran were analyzed by using SPME-GC/MS at normal temperature. There were 22 volatile components detected in green flower C. Kanran and 18 volatile components in purple flower C. Kanran. The species of ester components in green flower C. Kanran were more than purple flower C. Kanran. The changes of the contents of 2,5-octadecadiynoic acid, methyl ester , Z,Z,Z-1,4,6,9-no- adecatetraene in green flower C. Kanran and 4,7-dimethyl-4-octanol, geranyl acetone in purple flower C. Kanran were maximal, it may be the main reason for the fragrance differences between different color C. Kanran.4. According to the affects of florescence, cymbidium fragrance releasing and other factors, C. faberi florescence were divided into five stages. SPME-GC/MS method was used to analyze the changes of volatile components at different blooming stages of yellow-purple C. faberi, green C. faberi and C. ensifolium. Moreover, the daily changes of volatile components in yellow-purple C. faberi were analyzed by using TCT-GC/MS method.1) The analysis results of yellow-purple C. faberi florescence indicated that: Ocimene andα-farnesene were the main fragrance components at bud stage. (E、E)-Farnesol, methyl jasmonate and compound C were the main fragrance components at half opening stage. At full opening stage, the relative content of(E、E)-farnesol> methyl jasmonate>ocimene were high. At the end of full opening stage, the relative content of(E、E)-farnesol>compound C>ocimene were high. There were 10 components detected in the at the decay stage, they were high in alkanes relative content and had variety of species, ester compounds were not detected. The synthesis and release of ocimene increased at half opening stage, that of geranylacetone increased after half opening stage. (E、E)-Farnesol had the highest content in the half opening stage, full opening stage and decay stage, it was an important componentin yellow-purple C. faberi fragrance was more.2) The analysis results of green C. faberi florescence indicated that: Trans-ocimene and linalool were the main fragrance components at bud stage. The relative content of compound C and methyl jasmonate was up to 70% at half opening stage. The relative content of ocimene and compound C reached to 60% at full opening stage. At the end of full opening stage, the relative content of farnesol and compound C reached to 50%.There were 8 compounds detected at the decay stage, which had little affects to the fragrance. The relative content of ocimene changed obviously with the florescence, it indicated that the synthesis and release of ocimene is highly correlated. Compound C, was existed in half opening stage, full opening stage, end of full opening stage as main component, and less affected by florescence, which was the main component in green C. faberi fragrance.3) The volatile components of C. ensifolium during different florescence: The variation of the total content of volatile compounds of C. ensifolium was as follow. Since bud stage, the total content of volatile compounds increased with time. The total content of volatile compounds became to descend after reaching the peak. However, the variation of the total content was not obvious at the 2nd and the 4th day. In the all blooming period, the contents of pentadecane and cineole almostly didn’t change. It indicated that pentadecane and cineole didn’t directly affect the fragrance of the flower of C. ensifolium. There were 5 kinds of esters,such as methyl jasmonate B、cyclopentaneacetic acid, 3-oxo-2-(2-pentynyl)-, methyl ester detected at half opening stage. The content of them had been asceding until the 4th day of florescence then started descending. 12-Oxatricyclo[4.4.3.0(1,6)]tridecane-3, 11-dione, Z,Z,Z -1,4,6,9-nonadec- atetraene were also the main volatile components. The content of the 3 volatiles reached to the peak at the 2nd day of blooming then started descending.4) The daily changes of the volatile components of C. faberi: At 15:00, the content of alcohols was higher than other times, while there was a higher content of volatility in esters at about 11:00. Two kinds of methyl jasmonate were detected, which were called methyl jasmonate A and B. They both had high content of volatility in the day. The content of volatility of methyl jasmonate A was higher in the morning than in the afternoon, while methyl jasmonate B was reverse to jasmonate A. There was no an obvious changes in the content of volatile of longifolene. The content of volatile of ocimene was 4-5 times in the morning than in the afternoon. The contents of aldehydes、ketones and other components were low in all of the volatile components of C. faberi, and the variations were not obvious.更多还原