Rosa hybrida

A novel pigment has been isolated from the petals of Rosa hybrida with complex chromatographic techniques and the structure was elucidated with spectroscopic methods and high resolution fast-atom bombardement mass spectrometry, lH NMR, and FTIR. Anthocyanins were extracted from 7.9 kg of petals of Rosa hybrida cv. M me Violet with 80 per cent aqueous ACN containing 0.1 per cent TFA. The extract was purified in a Sephadex LH-20 column, and the fraction eluted with 80 per cent ACN was further fractionated in a HP-20 column using water, 15, 20 and 30 per cent ACN as mobile phases. The last fraction was lyophilized and separated by preparative RP-HPLC using an ODS column (50 X 5 cm i.d.). Solvents were 0.5 per cent aqueous TFA (A) and water-methanol... 

Y. Fukui, T. Kusumi, K. Masuda, T. Iwashita and K. Nomoto, Structure of rosacyanin B, a novel pigment from the petals of Rosa hybrida. Tetrahedron Lett. 43 (2002) 2637-2639. 

Sense Rosa hybrida Flower color changed from red to pale red 390... 

Eiroozabady, E. et al.. Regeneration of transgenic rose Rosa hybrida) plants from embryogenic tissue. Biotechnology, 12, 609, 1994. 

Tanaka, Y. et al.. Molecular cloning and characterization of Rosa hybrida dihydrofiavonol 4-reductase gene. Plant Cell Physiol, 36, 1023, 1995. 

Two classes of dimeric anthocyanins isolated from plants (section 10.2.6) have been identified in plants for the first time. One class includes pigments where an anthocyanin and a flavone or flavonol are linked to each end of a dicarboxylic acyl unit. The other class includes four different catechins linked covalently to pelargonidin 3-glucoside. During the last decade, seven new desoxyanthocyanidins and a novel type of anthocyanidin called P)Tanoanthocyanidins have been reported (Section 10.2.2). Toward the end of the 20th century, several color-stable 4-substituted anthocyanins, pyranoanthocyanins, were discovered in small amounts in red wine and grape pomace.Recently, similar compounds have been isolated from extracts of petals of Rosa hybrida cv. M me Violet, scales of red onion, and strawberries. About 94% of the new anthocyanins in the period of this review are based on only six anthocyanidins (Table 10.2). 

Circadian rhythmicity in emission of volatile compounds by flowers of Rosa hybrida L. cv. Honesty. Planta 207 88-95. 

Fig. 8.4 The ratios of the concentrations of odor volatiles change as a function of the time period of sampling, a) Diurnal emission of individual odor volatiles by flowers of Rosa hybrida exposured to a 12-h photoperiod shaded and non-shaded area,s correspond to periods of darkness and light. Each point represents the amount of a given volatile at a 3 h sampling period, b) Representation of the odor volatiles for each 3 h sampling period over a 24 h period (shown in a dotted box on (a)). The odors are represented on the x-axis as l=geraniol, 2=nerol, 3 itrone lol, 4=e-citral, 5=z-citral, 6=methyigeranylate, 7=caryophyllene, 8= J-cubebene, 9=dihydro-B-ionone, 10=hexylacetate, 1 l=2-phenylcthanol, 12-2-phenylethyl-acetate, 13-3,5 dimethyoxy toluene.

Reproduced from Helsper et al., Planta, 1998, Circadian rhythmicity in emission of volatile compounds by flowers of Rosa hybrida L. Cv. Honesty, vol. 207, iss. 1, pp. 88-95, with the permission of the authors and Springer. 

Figure 6.1.2 GC-MS chromatogram of fragrance chemicals from Rosa hybrida (adapted from...

To give an example of the many fragrance chemicals that can be present in an extract. Figure 6.1.2 shows a GC-MS chromatogram obtained in the analysis of Rosa hybrida. 

Volatile compounds have been found to be synthesized de novo in the cells of the plant tissues from which they are emitted [131, 132]. In flowers, their biosynthesis occurs in the epidermal cell layers, allowing easy escape of volatiles into the atmosphere [133-135]. While in some species, including Clarkia breweri and some rose varieties (e.g. Rosa x hybrida Baronne Edmond de Rothshild , Anna , The Mac Cartney Rose ), the biosynthesis of volatile constitnents of scent is localized on either side of the petals [136, 137], in others (snapdragon, Stephanotis floribunda, Nicotiana sua-veolens and Rosa x hybrida Lady Hillingdon ),... 

---