摘要:

The leaf oil ofCymbopogon distans(Steud.) Wats, chemotype Loharhket and the root oil ofCymbopogon jwarancusa(Jones) Schult. were examined by GC and GC/MS and found to qualitatively exhibit a very similar sesquiterpenoid composition. The sesquiterpenoid content of theC. DistansandC. Jwarancusaoils was 79.6% and 38.0%, respectively. Most of the sesquiterpenoids were isolated by liquid chromatography and their structures assigned on the basis of their IR, MS,1H- and13C-NMR spectra. The main components inC. distansleaf oil were eudesmanediol (34.4%) and 5-epi-7-epi-α-eudesmol (11.2%), while the largest sequiterpenoid component in the root oil ofC. jwarancusawas agarospirol (9.5%).

ISSN:1041-2905    

DOI:10.1080/10412905.1996.9700577

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Fruits of tetraploid (2n=44) and hexaploid (2n=66) specimensof Thapsia villosacollected at different locations have been investigated for their essential oil components. Analysis of the essential oils by means of GC and GC/MS has shown that their chemical composition is slightly affected by the chromosome number of die plants. Both tetra- and hexaploid specimens have limonene and methyl eugenol as main constituents. However, the amount of limonene is reduced in the hexaploid plants (14–26% vs 31–55% in the tetraploids) which are also characterized by discrete amounts of elemicin (trace-30.11%).

ISSN:1041-2905    

DOI:10.1080/10412905.1996.9700578

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The chemical composition of the essential oil ofAgeratum houstonianumMill. was investigated by GC and GC/MS. The essential oil was found to be a mixture of about 50 chemical compounds, of which precocene I (23.34%), precocene II (43.99%) and β-caryophyllene (9.18%) were identified as major constituents. Other chromene derivatives, present in lower concentration, have been identified and reported.

ISSN:1041-2905    

DOI:10.1080/10412905.1996.9700579

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The volatile leaf and flower oils fromAgastache rugosa(Fisch. et Mey) O. Kuntze were analyzed by GC and GC/MS and found to contain more than 40 mono- and sesquiterpenes, of which about 30 constituents have been identified. The oils are characterized by a high proportion of methyl chavicol (92.0% and 75.9% in the leaf and flower oils, respectively).

ISSN:1041-2905    

DOI:10.1080/10412905.1996.9700580

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The composition of the essential oil from the leaves and flowers ofOcimum gratissimumL. was analyzed by GC and GC/MS. Although the composition of both oils was similar, the quantity of individual components differed between them. Thymol and p-cymene were the major compounds in both oils.

ISSN:1041-2905    

DOI:10.1080/10412905.1996.9700581

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Two minor consituents from the essential oil ofRubus rosifoliushave been identified as isokessane and β-kessane by spectroscopic and chemical methods. Two dimensional NMR studies defined the stereochemistry of these ethers and enabled a complete C and H assignment to be proposed. The assigned structures are consistent with those of partially characterized ethers obtained chemically from kessane derivatives from Japanese valarian,Valeriana officinalis.Treatment of isokessane with sodium iodide/chlorotrimethylsilane gave β-kessane.

ISSN:1041-2905    

DOI:10.1080/10412905.1996.9700582

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Forty constituents (accounting for 99.96-94.96 wt% of total volatile constituents) have been identified in the oils of twelve lemon cultivars grown in Sardinia. A statistical analysis of data was performed using Principal Component Analysis (PCA) method; through this analysis most lemon cultivars could be clustered into two groups. The nucellar cv.Santa Teresa(165 and ICAS 146) andInternodato, which possess different essential oil compositions, could not be clustered into either of the two groups, in fact they were even differentiated from one another.

ISSN:1041-2905    

DOI:10.1080/10412905.1996.9700583

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The composition of the volatile fraction of 164 Italian sweet orange oils, laboratory-prepared from fruits of different cultivars, has been studied by GC and GC/MS. The following cultivars have been examined: Biondo comune, Navelina, Washington navel, Ovale, Valencia late (blond cultivars) Tarocco, Moro, Sanguinello (blood cultivars). The average composition of each of the cultivars is reported as is the standard deviation for each compound. As a result, the behavior of the classes of substances and of some of the components during the period analyzed are shown. Furthermore, the results are compared with those of previously analyzed commercial sweet orange oils.

ISSN:1041-2905    

DOI:10.1080/10412905.1996.9700584

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Four regimes for weed control were tested in field experiments for five years: mechanical weed control (three tillages); chemical weed control (Sinbar NP80 at 2kg/ha); combined-1 weed control (Sinbar NP80 at 2 kg/ha and one hoeing) and combined-2 weed control (Sinbar NP80 at 2 kg/ha and tree hoeings). The investigation was carried out with two speciesMentha piperitaL. (Clone No. 1) andMentha arvensisL. var.piperascensMalinv. (cv. Mentolna-14). It was established that the highest growth indices, fresh herbage and essential oil yields fromM. piperitaandM. arvensisvar.piperascenswere obtained when mechanical or combined (mechanical and chemical) weed control is used. In both species the essential oil composition, is not significantly affected by the method of weed control. The mechanical weed control contributes to the decrease of soil density in mint plantings which creates more favorable conditions for the increase of growth indices, the yields of fresh herbage, essential oil, and rhizomes. The rhizomes from both mint species produced when mechanical or combined (mechanical and chemical) weed control is used, are longest, with highest number of internodes and node buds.

ISSN:1041-2905    

DOI:10.1080/10412905.1996.9700585

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Essential oils produced from leaves ofAstronium fraxinifoliumSchott. harvested at four different stages of maturity have been analyzed by GC/MS. Z-Limonene (57.4%) was the principal component of young leaves of young plants and (E)-β-ocimene (94.8%) was the major constituent in mature leaves from young plants. In the adult plant, the principal constituent was also (E)-β-ocimene in both young leaves and in mature leaves in 63.2% and 81.6%, respectively.

ISSN:1041-2905    

DOI:10.1080/10412905.1996.9700586

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor