Improved germination in seeds of guayule (Parthenium argentatum Gray) following polyethylene glycol and gibberellic acid pretreatments

Suitable conditions for the pretreatment of seeds of guayule were determined with a view to improving germination. These included the addition of thiram (500 mg litre^-1), and applications of GA₄₊₇ alone, or in combination with polyethylene glycol. Significant improvements in the seed germination were seen following applications of PEG at -0.10 MPa. Simultaneous application of GA₄₊₇ with priming improved soil emergence and germination over a wide range of temperatures. No beneficial effects of PEG priming were evident on seed storage.     

Development of a liquid flow-through system to inhibit browning in callus cultures of guayule (Parthenium argentatum Gray)

Calli of P. argentatum were grown on a newly designed liquid nutrient flow-through system which facilitated the subculturing of calli and delayed browning for 6 weeks. Friable calli were obtained on half-strength Gamborg B5-medium supplemented with 0.05 mgl⁻¹ 2,4-dichlorophenoxyacetic acid. Shoots developed on media supplemented with 0.2 mgl⁻¹ benzylaminopurine but lacking 2,4-dichlorophenocyacetic acid.     

Chemical Studies on the Essential Oils of Foeniculum vulgare

Twenty seven chemical constituents of oils from sweet leaves, flowers and fruits of Foeniculum vulgare Mill. are examined by GC and GC-MS with both different chromatographic columns. They are 1,1-diethoxyethane, α-thujene, α-pinene, camphene, sabinene, β-pinene, myrcene, α- phellandrene, p-cymene, limonene, cineole, γ-terpinene, fenchone, camphor, terpinen-4-ol, α-terpineol, estragole, verbenone, fenchol acetate, carveol, trans-fenchol acetate, carvone, anethole, anisaldehyde, trans-anethole, methoxyphenyl acetone and benzoic acid, 4-methoxy-, othylester. The limonene is 57.8% in the essential oil from leaves, 34.2% from flowers, 13.1% from fruits, The trans-anethole is 21.8% in the essential oil from leaves, 41.2% from flowers, 63.4% from fruits.     

A Study on Chemical Components of Essential Oils from Citrus bergamia and Its Close Relatives and Its Taxonomy

Citrus bergamia Risso. is a rare perfumery plant. Taxonomists have different views on the taxonomy of C. bergamia. Chemical components of leaf and peel essential oils from C. bergamia, and its close relatives, C. limon, C. aurantifolia and three varieties of C. aurantium, were analyzed by GC and GC-MS. The analytical result shows that the chemical compositions of the leaf essential oils from C. bergamia are basically the same as those from three varieties of C. aurantium. Their main components are linalool (29.19-39.75% )and linalyl acetate (24.73-30.24% )etc., and contents of other components are also similar. But their peel essential oils are different. The peel essential oils from C. bergamia contain less limonene (29.94%) than those from C. aurantium (92.55-94.31% ) and less beta-pinene (3.00%) and y-terpinene(3.48% )than those from C. limon or C. aurantifolia (respectiyely 9.16% and 10.42% ) . The peel essential oils from C. bergamia contain not only as much linalool (22.20%) and linalyl acetate (32.66%)as those in the leaf essential oils from C. aurantium, but also as much limonene(29.94% )as that in the peel essential oils from C. limon or C. aurantifolia . The contents of limonene are close to those of the essential oils from C. aurantifolia. This result shows that C. bergamia may be a natural hybrid between C.aurantium and C. aurantifolia, as proposed by Sinclair W. B.     

Magnesium ion regulation of in vitro rubber biosynthesis by Parthenium argentatum Gray

Natural rubber is produced by a rubber transferase (a cis-prenyltransferase). Rubber transferase uses allylic pyrophosphate to initiate the rubber molecule and isopentenyl pyrophosphate (IPP) to form the polymer. Rubber biosynthesis also requires a divalent metal cation. Understanding how molecular weight is regulated is important because high molecular weight is required for high quality rubber. We characterized the in vitro effects of Mg(2+) on the biosynthetic rate of rubber produced by an alternative natural rubber crop, Parthenium argentatum (guayule). The affinity of the rubber transferase from P. argentatum for IPP.Mg was shown to depend on the Mg(2+) concentration in a similar fashion to the H. brasiliensis rubber transferase, although to a less extreme degree. Also, in vitro Mg(2+) concentration significantly affects rubber molecular weight of both species, but molecular weight is less sensitive to Mg(2+) concentration in P. argentatum than in H. brasiliensis.     

海南木莲叶挥发油化学成分研究

目的：分析海南木莲叶的挥发油成分。方法：采用水蒸气法提取挥发油,气相色谱-质谱-计算机联用技术分析。结果：共鉴定出49种化合物,占挥发油总量的99．99％,其中主要成分是橙花叔醇（16．44％）;3,7-二甲基-2,6-辛二烯-1-醇（5.27％）;3,7-二甲基1,6-辛二烯-3-醇（5．12％）;α-丁香烯（4．97％）和丁香烯（4．48％）。     

The Chemical Components of Essential Oils from the Leaves of 110 Species and Cultivars of Citrus Plants

Seventy-two chemical components of essential oils from the leaves of 110 species and cultivars of Citrus were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Among the plants analyzed, there are 3 species in papeda, 12 species and cultivars in Osmocitrus, 18 cultivars in C. aurantium L., 15 cultivars in C. sinensis Osbeck, 16 species and cultivars in Citrophorum, 16 species and cuhivars in Cephalocitrus, 30 species and cultivars in Acrumen. As resources of essential oils, some valuable plants were found such as Citrus hystrix D. C., C. junos (Sieb.) Tan. cv. Xiecheng, C. junos (Sieb.) Tan. cv. Luohancheng and C. tankan Hayata. Our study has provided systematic data of the chemical components of the essential oils for the taxonomic work of Citrus plants.     

Stuies on the Chemical Constituents of the Essential Oils from the Leaves of Aglaia odorata Lour

This paper shows the chemical constituents of the essential oils from the leaves of Aglaia odorata Lout. grown in Zhangzhou. By the aid of GC-MS-DS., IR., the following components have been separated and identified: linalool, hendecane, α-copaene, β-elemene, β-caryophyllene, α-humulene, aromadendrene, γ-cadinene, α-himachalene, δ-cadinene, β-guaiene, γ-gurjunene, γ-elemene, humulene epoxide-Ⅰ, humulene epoxide-Ⅱ, β-elemene-9β-ol, β-humulene-7-ol, nerolidol, earyophyllenol-1, farnesol, β-santalol, elemol. This will provide scientific basis for further develophment of the essential oils of the plants of Aglaia Lour.     

The Chemical Constituents of the Essential Oil from the Flowers,Leaves and Peels of Citrus aurantium

Citrus aurantium L. var. amara Engl., is a better species of sour oranges. There are essential oils in the flowers, the peels, the leaves and the branches of C. aurantium. The flower oil can be used in the preparation of perfumes of high quality. The peel oil is used mainly for the flavor-endowing of soft drinks, alcoholic drinks, bread, confectionaries and cakes. In order to control the quality of the essential oils and to improve them, we have systema- tically studied the chemical constituents of the flowers, the leaves and the peals of C. aurantium with our preparation. 12 main components were separated by silica gel column chromatography. The following 33 chemical components were identified by IR, GC-MS and GC retention index: α-thujene, α-pinene, camphene, β-pinene, myrcene, limonene, β-ocimene, trans-linalooloxide (furanoid), cis-linalooloxide (furanoid), linalool, 1,4-p-methadien-7-ol, trans-pinocarveol, camphor, terpinen-4-ol α-terpineol, nerol, citral-b, geraniol, linalylacetate, citrala, trans-linalooloxide (pyranoid), methyl anthranilate, terpinyl acetate, cis-linalooloxide (pyranoid), neryl acetate. geranyl acetate, nonanal, β-caryophyllene, α-humulene, γ-muurolene, β-nerolidol, farnesol, α- nerolidol. GC retention index of 33 compounds were measured. A fast method for routine determination is presented.     

Study on Chemical Constituents from the Essential Oil of Tagetes erecta

The essential oil of leaves and the absolute from flower of Tagetes erecta were analysed by GC, GC/MS, IR, column chromatography. About 50 compounds in the essential oil have been identified, most of then are terpenone. 28 compounds in absolute have been identified. γ-, △-cadinene, cis-caryophyllene and other sesquiterpenes are major constituents in absolute The essential oil has good antibiotic activity and no irritability to human skin. It is a kind of useful natural fragrance.     

木里柠檬叶精油化学成份的研究

用毛细管气相色谱-质谱-计算机数据联用技术、标准品叠加法和毛细管保留指数定性法分析了木里柠檬(Citrus Liilion(L.)Burm.f.)的叶精油化学成分。从水蒸汽蒸馏叶精油被分离的110多个色谱峰中鉴定了41种化合物,并测定了其相对含量。其主要成分是香叶醛(21.3058％)、橙花醛(13.9580)、d-柠檬烯(9.8359)、β-水芹烯(9.3297)、橙花醇(4.4657)、乙酸橙花酯(2.8162)、香茅醛(2.6338)、乙酸芳樟酯(2.2179)、α-水芹烯(2.0390)、香芹酮(2.0213)、6-甲基-5-庚烯-2-酮(1.7250)和乙酸香叶酯(1.6586)。被鉴定的成份占总成份的96.6652％     

假烟叶树叶挥发油化学成分分析

采用水蒸汽蒸馏法、两相溶剂萃取法提取,运用毛细管气相色谱-质谱联用法结合计算机检索对茄科植物假烟叶树(Solanum verbascifoliumL.)叶挥发油的化学成分进行分析和鉴定。其新鲜叶片提取10 h的挥发油得率为0.0611%。经毛细管色谱分离出18个峰,共鉴定出17种化合物,占挥发油总量的99.73%;用气相色谱面积归一化法计算各组分的相对含量,其主要化学成分为:大牻牛儿烯D(37.07%),咕巴烯(26.29%),1β-(1-甲基乙基)-4,7-二甲基-1α,2,4a()β,5,8,8a()α-六氢萘(13.63%),石竹烯(8.03%),1-β乙烯基-1-α甲基-2,β4-β双(1-甲基乙烯基)-环己烷(5.81%),-γ榄香烯(2.16%),α-筚澄茄油烯(2.06%),异喇叭烯(0.98%)。以上8种化合物占总挥发油含量的90.22%。     

赤楠叶精油的化学成分及其抗菌活性

以水蒸汽蒸馏法提取赤楠叶精油,得率约0．51％,用GC-MS分析其化学成分,主要为石竹烯(37．623％)、α-瑟林烯(9.627％)、β-瑟林烯(9．408％)、柯巴烯(5．360％)等。抗菌实验显示该精油对金黄色葡萄球菌、枯草芽孢杆菌、大肠杆菌、普通变形杆菌、藤黄八叠球菌等具有较强的抑杀活性。     

Chemical Compositions,Antioxidant and Antimicrobial Activities of Essential Oils of Psidium guajava L. Leaves from Different Geographic Regions in China

Hydrodistilled essential oils (EO) of Psidium guajava L. leaves from different regions in China were analyzed by GC and GC/MS. The samples from Guangdong Province displayed high EO yields (0.61 – 0.75%, v/w). A total of 50 components, representing over 98.00% of the EOs, were identified and semi‐quantitatived. The major constituents of EOs included β‐caryophyllene (17.17 – 31.38%), γ‐gurjunene (9.17 – 15.22%), τ‐cadinol (1.35 – 10.02%) and calamenene (2.13 – 7.80%). The terpenoids in all sample oils were dominated by sesquiterpenes hydrocarbons (70.18 – 84.35%), followed by oxygenated sesquiterpenes (9.89 – 22.19%). The similarities and differences among EOs from different samples were evaluated by hierarchical cluster analysis and principal component analysis methods. The IC₅₀ values of EOs from different regions were between 18.52 – 33.72 mg/ml (DPPH) and 13.12 – 25.15 mg/ml (ABTS⁺). The FRAP value of EO from Guangdong Province was 7.34 – 9.13 mmol Vc/g DM, while the FRAP value of EO from Taiwan Province was 2.29 – 2.36 mmol Vc/g DM. The antimicrobial tests revealed that EO had a higher antimicrobial activity against all Gram‐positive bacteria and two fungi. Moreover, EO from P. guajava leaves of Guangdong Province showed the highest antimicrobial activity. These properties can be considered in the design of industrial products and for further application in the food, pharmaceutical and cosmetic industries.     

紫苏叶精油化学成分分析研究

用GC -MS对紫苏叶精油进行分析鉴定 ,结果表明 :紫苏叶精油中主要化学成份为甲基紫苏酮 ,其质量分数为 5 7.5 1%。     

Chemical Constituents of the Fssential Oils from the Leaves of Laurus nobilis and Tendency in Changes of the Constituents Month by Month

The chemical constituents of the essential oils from the leaves of Laurus nobilis L., have been identified both by capillary GC-MS and fused silica capillary GC Kovats retention in,lex of components. From laurel leaf oil, 45 compounds have been identified, among which, 19 compounds such as 1,4-cineole, sabinene hydrate etc. have not been found in the leaf oil previously. This paper studies systematically the constituents of essential oil from dry, fresh leaves, and those of annual, perennial, different district, and reported the changes of the chemical constituents month by month. Results showed that the yield of essential oil and 1,8-cineole content is the highest in July.