Composition of Peel Oil from Citrus Unshiu.

α-Pinene, terpinolene, δ-elemene, α-copaene, α- and β-humulene, β-sesquiphellandrene, γ-cadinene, acetate of p-menthen-1-ol-9 and acetate of p-menthadien-1, 8(10)-ol-9 were newly identified as the volatile constituents of peel oil from C. Unshiu. Aroma characteristics of C. Unshiu are discussed on the basis of quantitative analysis.

Comparison of aroma patterns of peel oil among various citrus fruits was also carried out with head space analysis.     

Constituents of Cold-Pressed Peel Oil of Citrus natsudaidai Hayata

A study was made on the elaborate separation and identification of the fraction, boiling higher than monoterpene hydrocarbons, of cold-pressed peel oil of Citrus natsudaidai Hayata, by using fractional distillation under reduced pressure, adsorption and gas chromatography, infrared, mass and proton magnetic resonance spectrometry. The following components were identified; in sesquiterpene hydrocarbon series: copaene, β-elemene, β-ylangene, caryophyllene, aromadendrene, farnesene, α-selinene, δ-cadinene, calamenene, α-calacorene; and among oxygenated compounds: n-nonyl alcohol, n-decyl alcohol, linalool, α-terpineol, terpinen-4-ol, nerolidol, elemol, n-octyl aldehyde, n-decyl aldehyde, perillaldehyde, carvone, n-octyl acetate, n-decyl acetate, geranyl acetate, perillyl acetate and acetic ester of p-methadiene-1,8(10)-ol-9.     

Microbial Production of Pectin from Citrus Peel

A new method for the production of pectin from citrus peel was developed. For this purpose, a microorganism which produces a protopectin-solubilizing enzyme was isolated and identified as a variety of Trichosporon penicillatum. The most suitable conditions for the pectin production were determined as follows. Citrus (Citrus unshiu) peel was suspended in water (1:2, wt/vol), the organism was added, and fermentation proceeded over 15 to 20 h at 30°C. During the fermentation, the pectin in the peel was extracted almost completely without macerating the peel. By this method, 20 to 25 g of pectin was obtained per kg of peel. The pectin obtained was special in that it contained neutral sugar at high levels, which was determined to have a molecular weight suitable for practical applications.     

Isolation and Characterization of Pectin from Peel of Citrus tankan

A pectin was extracted from the peel of Citrus tankan with a yield of 2.75%. The uronic acid content was 80.0%, and the degree of methoxylation was 63.2%. The pectin was composed of D-GalA, D-Gal, L-Ara and L-Rha in the molar ratio of 100:11.3:3.6:2.6. The molecular weight was estimated to be approximately 9.2×10⁴. The pectin formed a gel by conventional procedures.     

一种适合从柑橘果皮提取总RNA的方法

柑橘果皮由于富含果胶、酚类物质等干扰RNA分离的物质,较难提取到纯度高的RNA。本试验建立了一种适于从柑橘果皮提取RNA的方法,从脐橙和蕉柑两种柑橘的果皮提取总RNA,经凝胶电泳、紫外分光光度法检测所提RNA的品质。研究结果表明,该法所提RNA条带清晰、无降解。OD260/OD280接近2.0,具有较高的纯度。RT-PCR试验结果进一步表明,该法提取的RNA纯度高,完全能够用于后续的分子生物学研究。     

Evaluation of Characteristic Aroma Compounds of Citrus natsudaidai Hayata (Natsudaidai) Cold-Pressed Peel Oil

The characteristic aroma compounds of Citrus natsudaidai Hayata essential oil were evaluated by a combination of instrumental and sensory methods. Sixty compounds were identified and quantified, accounting for 94.08% of the total peel oil constituents. Limonene was the most abundant compound (80.68%), followed by γ-terpinene (5.30%), myrcene (2.25%) and α-pinene (1.30%). Nineteen compounds which could not be identified in the original oil were identified in the oxygenated fraction. Myrcene, linalool, α-pinene, β-pinene, limonene, nonanal, γ-terpinene, germacrene D, and perillyl alcohol were the active aroma components (FD-factor > 3⁶), whereas β-copaene, cis-sabinene hydrate and 1-octanol were suggested as characteristic aroma compounds, having a Natsudaidai-like aroma in the GC effluent. Three other compounds, heptyl acetate, (E)-limonene oxide and 2,3-butanediol, which each showed a high RFA value (>35) were considered to be important in the reconstruction of the original Natsudaidai oil from pure odor chemicals. The results indicate that 1-octanol was the aroma impact compound of C. natsudaidai Hayata peel oil.     

Lipid Composition of Citrus Leaves from Plants Resistant and Susceptible to Citrus Bacterial Canker

The contents and composition of lipids in citrus leaves in relation to their general resistance to infection by strains of Xanthomonas campestris pv. citri (Xcc) were determined. The composition and contents of total polar lipids and phospholipids and the degree of fatty acid unsaturation were significantly different between resistant and susceptible species. Leaves from resistant plants had less phospholipids, but more free sterols than those from susceptible plants. The predominant fatty acids in the phospholipids were palmitic (16:0), linoleic (18:2) and α-linolenic acid (18:3). The degree of fatty acid unsaturation was higher in susceptible plants than in resistant plants. Major phospholipids in citrus leaves were phosphatidylchloline (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), and phosphatidylinositol (PI). β-Sitosterol, campesterol and lanosterol were major sterols in the leaves of citrus plants with resistant species having a higher ratio of free sterols to total phospholipids than susceptible species. Differences in lipid metabolism may contribute to differences in Xcc-resistance of citrus leaves.     

Ethylene-controlled Induction of Phenylalanine Ammonia-lyase in Citrus Fruit Peel

l-Phenylalanine ammonia-lyase (PAL) activity is low in the external layers (flavedo) of intact mature grapefruit peel. Flavedo discs evince upon incubation increasing PAL activity and ethylene production. Light has no effect in enhancing PAL activity in discs. Exogenous ethylene stimulates PAL activity in the flavedo of intact mature grapefruits (half maximum stimulation at 15 ppm); such activity rapidly decreases when fruit is removed from the ethylene containing atmosphere. Carbon dioxide inhibits both ethylene production and PAL activity of discs; exogenous ethylene only partly relieves PAL inhibition. Cycloheximide inhibits both PAL activity and ethylene production by flavedo discs. The same concentration of cycloheximide also inhibits PAL activity of discs in the presence of exogenous ethylene. Protein synthesis seems therefore to be needed at both levels of ethylene evolution and enhancement of PAL activity.     

Chemotaxonomic Study of Citrus,Poncirus and Fortunella Genotypes Based on Peel Oil Volatile Compounds - Deciphering the Genetic Origin of Mangshanyegan (Citrus nobilis Lauriro)

Volatile profiles yielded from gas chromatography-mass spectrometry (GC-MS) analysis provide abundant information not only for metabolism-related research, but also for chemotaxonomy. To study the chemotaxonomy of Mangshanyegan, its volatile profiles of fruit and leaf and those of 29 other genotypes of Citrus, Poncirus, and Fortunella were subjected to phylogenetic analyses. Results showed that 145 identified (including 64 tentatively identified) and 15 unidentified volatile compounds were detected from their peel oils. The phylogenetic analysis of peel oils based on hierarchical cluster analysis (HCA) demonstrated a good agreement with the Swingle taxonomy system, in which the three genera of Citrus, Poncirus, and Fortunella were almost completely separated. As to Citrus, HCA indicated that Citrophorum, Cephalocitrus, and Sinocitrus fell into three subgroups, respectively. Also, it revealed that Mangshanyegan contain volatile compounds similar to those from pummelo, though it is genetically believed to be a mandarin. These results were further supported by the principal component analysis of the peel oils and the HCA results of volatile profiles of leaves in the study.     

苔藓Bazzania japonica挥发油的化学成分研究

采用水蒸气蒸馏法提取苔藓Bazzania japonica的挥发油,用毛细管色谱法对挥发油进行了分析,采用归一化法确定各组分的相对含量,并用GC-MS联用技术对分离的化学成分进行鉴定。经计算机检索并结合文献调研,共鉴定出38个化合物,占挥发油总量的83％,其中含2个单萜、31个倍半萜（其中11个为含氧倍半萜）和4个二萜（其中1个为含氧二萜）,主要成分为4-epi-11-nor—aristola-1（10）,11-diene（10．5％）,4-epi-11-nor-aristo-la-1,9,11-triene（6．5％）,β-caryophyllene（8．0％）,β—barbatene（7．2％）,globulol（8．8％）,aristol-1（10）-en-12-ol（9．1％）,和tridensenone（8．7％）.     

Mineral Content of the Pulp and Peel of Various Citrus Fruit Cultivars

Biological Trace Element Research - The aim of the study was to compare the mineral content between the peel and the pulp of citrus fruits and to determine which citrus fruit, among orange (Citrus...     

Ethylene-induced Formation of ABA in Citrus Peel as Related to Chloroplast Transformations

When mature green harvested Shamouti oranges (Citrus sinensis L. Osbeck) were exposed to 35 μl/liter of ethylene, a 3-fold increase in free abscisic acid (ABA) of the flavedo could be detected after 12 hours and a 10-fold increase after 24 hours, while chlorophyll destruction did not exceed 20%. The increase in free ABA continued up to 24 hours and leveled off. Bound ABA accumulated strongly after 24 hours suggesting that excess of free ABA was being converted into the bound form. Similar increases in ABA upon exposure to ethylene occurred also in fully mature orange fruits which had already lost all of their chlorophyll, in white and green portions of the flavedo of variegated lemons, and in the colorless albedo of Eureka lemons.     

MPTA对柑橘果皮类胡萝卜素形成的影响

以宽皮柑橘“本地早”为试材 ,研究了 2 (4 甲基苯氧 )三乙基胺 (MPTA)处理对柑橘果实外观颜色的影响 ,并探讨其与相关类胡萝卜素消长的关系及与糖含量变化的可能联系。结果表明 :MPTA处理促进柑橘果皮组织中类胡萝卜素 (主要为番茄红素 )的生物合成 ,使果皮颜色由淡橙黄色转为红色 ;随着番茄红素的积累 ,其上游前体物质葡萄糖含量下降 ,而其下游产物β 隐黄质、玉米黄素的合成不受影响     

Sterol Composition in the Pollens of Citrus unshiu Marcov. and Citrus sinensis Osbeck

Bacillus brevis secretes a large amount of cell wall proteins into the culture medium. For construction of Bacillus brevis expression-secretion vectors of human erythropoietin (EPO) and the extracellular domain of mouse erythropoietin receptor (sEPOR), cDNA for each mature form was inserted into a plasmid containing the promoter region and the signal-peptide encoding region of a cell wall protein. Culture supernatants of transformants were affinity purified using a monoclonal antibody-fixed gel for EPO and an EPO-fixed gel for sEPOR. The affinity purification efficiently removed unwanted proteins, giving samples with sufficiently high purity to analyze amino acid sequences of N-terminal regions and biological activities. Combination of this secretory production and affinity purification may facilitate isolation of a large amount of pure EPO and sEPOR, and is useful for further understanding the molecular mechanism of interaction between EPO and EPOR.     

Composition of soluble cuticular lipids and water permeability of cuticular membranes from Citrus leaves

Water permeability and composition of soluble cuticular lipids of isolated cuticular membranes from leaves of Citrus aurantium L. were investigated for 3 successive years. The average water permeability coefficient determined using 169 cuticular membranes was 1.09·10^–7 cm s^–1 with a standard deviation of 0.78·10^–7 cm s^–1. There were no significant differences in water permeability between years. Cuticular membranes are characterized by a great variability in water permeability both within and between years. Both water permeability of individual membranes and variability between membranes are shown to be determined by soluble cuticular lipids contained within the cuticular membranes. The soluble cuticular lipids of Citrus leaves are composed of fatty acids, primary alcohols, esters, and hydrocarbons. They occur in amounts of 9.84 g cm^–2, which represents approx. 3% of the total mass of isolated cuticular membranes. The specific weight of cuticular membranes (365.4 g cm^–1) and total amount of soluble cuticular lipids did not vary significantly between years. Significant differences were observed for the amounts and composition of the constituent classes of lipids. Six homologues comprise 86% of the fatty acids (C₁₆; C₁₈; C₁₉; C₂₁; C₂₄; C₂₆), 83% of the primary alcohols (C₂₄; C₂₆; C₂₈; C₃₀; C₃₂; C₃₄) and 88% of the esters (C₃₆; C₃₈; C₄₀; C₄₁; C₄₂; C₄₄). Eleven major homologues amount only to 62% of the total hydrocarbons (C₁₆; C₁₇; C₁₈; C₂₀; C₂₆; C₂₇; C₂₉; C₃₀; C₃₁; C₃₂; C₃₃). Variability in the composition of soluble cuticular lipids between years was much smaller than variability of water permeability and, therefore, no relation between composition of soluble cuticular lipids and water permeability could be found. It is suggested that this may be due to the fact that the lipid composition observed represents the averages of 20 to 30 membranes analyzed so that differences between individual membranes may have been leveled out.Abbreviations CM cuticular membranes - MX polymer matrix - P_d permeability coefficient for diffusion of water - SCL soluble cuticular lipids - MES morpholinoethane sulphonic acid     

石榴籽油的提取及成分分析

采用正交试验方法研究了超临界CO_2萃取石榴(Punica granatum L)籽油的技术体系,并用气相色谱-质谱联用仪对石榴籽油的化学成分进行了分析。结果表明,超临界CO_2萃取石榴籽油的最佳工艺条件为:萃取压力25 MPa,萃取温度30℃,分离温度55℃,萃取时间70min,在此条件下油脂产率为20.4%。GC-MS分析的结果显示,石榴籽油的主要成分是脂肪酸。饱和脂肪酸以棕榈酸为主,不饱和脂肪酸主要是亚麻酸和亚油酸,占脂肪酸总量的86.86%。     

早熟金柚果皮挥发油的提取及GC-MS分析

采用水蒸气蒸馏法提取早熟金柚果皮挥发油,通过正交实验优选获得早熟金柚果皮挥发油提取的工艺参数,结果表明：早熟金柚果皮挥发油的最佳提取工艺是将柚皮粉碎60 s,加水5倍,提取6 h。采用GC-MS联用技术对早熟金柚果皮挥发油的化学成分进行分离鉴定,共分离出44个峰,鉴定出了其中的25种化合物,占峰面积的98.43%。用面积归一化法测定了各个组分的相对百分含量,其主要成分有柠檬烯（65.82%）、β-月桂烯（25.52%）、4-侧柏烯（1.78%）、紫苏烯（0.44%）、氧化芳樟醇（0.42%）。     

裂叶荆芥不同部位香精油组成研究

采用水蒸气蒸馏法,分别从裂叶荆芥的叶、茎和花三个不同部位提取香精油并进行气相色谱/质谱分析.结果发现,叶、茎、花的香精油分别含有23、29、26种组分.叶和花香精油的组成和含量基本相似,主要成分是含量分别为15.09%、14.51%的薄荷酮和29.26%、31.36%的(+)-胡薄荷酮等单萜化合物以及含量分别为17.09%、5.00%的α-律草烯等倍半萜.而茎香精油的萜类化合物含量较低,含薄荷酮为4.15%,(+)-胡薄荷酮为7.68%,但其乙酯含量相对较高,如(E)-9-十六碳烯酸乙酯含量为11.92%,异戊酸乙酯为9.38%.