Home About us Contact
|
Home About us Contact | ||
|
|
||
Flower Scent (flower + scent)
Selected AbstractsSampling flower scent for chromatographic analysisJOURNAL OF SEPARATION SCIENCE, JSS, Issue 11 2008Elena E. Stashenko Abstract The analysis of flower volatiles requires special methods for their isolation with enrichment. Living flowers show a continuous change in their volatile profile that depends on intrinsic (genetic) and external (light, temperature, hydric stress) factors. Excised flowers suffer rapid deterioration and loss of volatiles. While industrial isolation methods for flower volatiles are well established, those at the laboratory-scale experience progressive development, in the search for higher sensitivity, reproducibility, and simplicity. This review covers the flower scent sampling methods most commonly employed during the last decade, and includes comments on their strengths and limitations. The strengths of headspace solid-phase microextraction (HS-SPME) for in vivo monitoring are emphasized with the examples of monitoring the circadian variation of Brugmansia suaveolens flower scent and of volatile aldehyde detection in flower scent using on-fiber derivatization. [source] SPME , A valuable tool for investigation of flower scentJOURNAL OF SEPARATION SCIENCE, JSS, Issue 8 2003Petr Barták Abstract A novel Headspace Solid Phase Microextraction (HS-SPME) protocol is proposed for the analysis of floral scent. Volatile compounds emitted from the flower are collected on a Carboxen/PDMS fiber for 1 hour, transferred to the GC, and analyzed by GC/MS. The method completely eliminates the use of organic solvents, does not require special instrumentation, and may readily be performed in the field without access to mains electricity and other energy supplies. The method is robust, sensitive, and reduces the sampling stress on the investigated plant. Since enzymatic reactions in living flowers may cause changes in the composition of emitted fragrance, dried rosemary (Rosmarinus officinalis L.) was used as a stable standard for the method development and optimization. In addition, grape wine was also suggested as homogeneous, bio-compatible, and relatively stable standard of pronounced and typical scent for the same purpose. The optimized method was used for the comparative investigation of the fragrances emitted by two different species , Lathyrus vernus (L.) and Orchis pallens (L.). Several monoterpenes (C10 compounds) were found as the main fragrance components of lathyrus, while sesquiterpenes (C15 compounds) were typical for the orchid. [source] A simple floral fragrance and unusual osmophore structure in Cyclopogon elatus (Orchidaceae)PLANT BIOLOGY, Issue 4 2009A. P. Wiemer Abstract We studied gland morphology, anatomy and the chemical composition of the floral fragrance in the sweat bee-pollinated orchid Cyclopogon elatus. This is apparently the first such analysis for any Cyclopogon species, and one of very few studies in which both odour and osmophore are characterised in a nectar-rewarding orchid. Structures responsible for floral scent production were localised with neutral red staining and histochemical assays for lipids and starch. Their morphology and anatomy were studied with scanning electron microscopy and light microscopy thin sections, respectively. Fragrance samples were collected using SPME fibres and analysed with GC-MS. Anatomical evidence suggests that two parallel oval-shaped patches of unicellular trichomes on the abaxial surface of the labellum are osmophores. These are rich in stored lipids, while the parenchyma surrounding the vascular bundles contains starch. Only freshly opened flowers produced odours, while buds and withered flowers lacked scent. The chemical composition of the odour was dominated (>99.8%) by a single compound, trans-4,8-dimethyl-nona-1,3,7-triene (DMNT). Gland anatomy and position on the outside of the perianth are unusual for scent glands in general. The presence of DMNT, a nearly ubiquitous compound in herbivore-induced vegetative emissions and one of the major floral volatiles of Yucca, is not surprising in view of hypotheses on the evolutionary origin of flower scents, suggesting that wound volatiles are utilised as kairomonal attractants by florivores whose activities result in pollination. [source] Die facettenreiche Welt der Apocarotinoide.BIOLOGIE IN UNSERER ZEIT (BIUZ), Issue 5 2009Aromen und Hormone, Düfte, Farben Abstract Apocarotinoide werden durch hochspezifische Spaltungsreaktionen oxidativer Enzyme an den Doppelbindungen von Carotinoiden maßgeschneidert. Es können neue Chromophore entstehen, die zusätzliche Nuancen des gelb-roten Farbspektrums eröffnen. Farblose C13-Apocarotinoide können potente Duft- und Aromastoffe sein. Viele Apocarotinoidfunktionen mit Hormoncharakter sind lange bekannt (Abszisinsäure in Pflanzen, Trisporsäure in Pilzen, Retinsäure in Säugern). Eine neue Klasse von Apocarotinoid-Pflanzenhormonen, die die Sprossverzweigung der Pflanzen mitbestimmen, wurde kürzlich als Strigolactone identifiziert. In ihrer Biosynthese wie auch in der von mykorrhizainduzierten C13/C14-Apocarotinoiden treten mehrstufige aufeinanderfolgende Carotinoidspaltungsreaktionen auf. Das Wissen über Synthesewege und Funktionen von Apocarotinoiden eröffnet neue Perspektiven für Anwendungen im Zierpflanzenbau, bei der Bekämpfung parasitischer Unkräuter und in der Beeinflussung von Blütendüften und Fruchtaromen. Apocarotenoids are tailored from carotenoids by highly specific oxidative enzymes cleaving different double bonds. New chromophores can be generated, which make additional nuances of the yellow-red color spectrum available. Colorless C13 apocarotenoids can constitute potent scent and aroma compounds. Many apocarotenoid hormone functions are well-known (abscisic acid in plants, trisporic acid in fungi, retinoic acid in mammals). A new class of apocarotenoid plant hormones, which take part in determining shoot branching has recently been identified as strigolactones. In the biosyntheses of strigolactones and mycorrhiza-induced C13/C14 apocarotenoids several sequential cleavage reactions occur. The knowledge about biosynthetic pathways and functions of apocarotenoids opens up new perspectives for its application in horticulture and in the control of parasitic weeds as well as in the manipulation of flower scents and fruit aromas. [source] | ||||||||||