Identification of novel compounds in rose absolute with gas chromatography/high‐resolution mass spectrometry

Abstract

Roses have beautiful shapes and colors, which make them attractive for horticultural purposes, and more than 18,000 varieties have been created by crossings. 1 Rose is also one of the major sources of natural ingredients for the fragrance industry. Indeed, the Queen of the flowers brings exceptional facets to perfume compositions. Among the 200 rose species, Rosa centifolia and Rosa damascena are the two main species used by the fragrance industry. 1 Rosa centifolia is mainly farmed in France and Morocco, 2,3 while Rosa damascena is mainly farmed in Bulgaria, Turkey, China, India and Egypt. 2,3 Rosa damascena is used to produce essential oil (yield: 0.03%), concrete (yield: 0.17%-0.40%), and absolute (yield: 50%-65% from concrete extraction), whereas Rosa centifolia is only used for concrete and absolute, and is not economically viable for essential oil. 4 Due to its rarity Rosa centifolia is one of the most precious species used in perfumery for absolute. Obtention of rose concrete from fresh rose flowers is a well-known process. Rose concrete is produced by solvent extraction, generally using petroleum ether and/or "generic" hexane. 2,[5][6][7][8] In contrast with recent allegations, 9 various mixtures of C6 hydrocarbons with low n-hexane content are preferred, rather than pure n-hexane, a CMR and neurotoxic substance. Benzene is no longer used for solvent extraction due to his high toxicity. 10 Moreover, to date extraction of fresh rose flowers with liquefied gases or supercritical CO 2 have not reached any significant importance. Rose concrete is a waxy, semi-solid material, that is, hardly soluble in ethanol. So, concrete is poorly used in its native form for fragrances and is further transformed into absolute using ethanol. Concrete is dissolved in hot ethanol (between 35 and 40°C) and then filtered at glacial temperature (−20°C). Ethanol is finally evaporated under vacuum to get the absolute. 2,6,11,12 Rose absolute is a dark red liquid with a typical rose odor. Rose absolute is considered to represent the more genuine character of rose fragrance. Indeed,

New esters from the essential oil of dry flowers of elder (Sambucus nigra L.)

“…We postulated that these are most likely esters of (Z)-hex-3-en-1-ol and geraniol because the corresponding alcohols occur in notable quantities in all samples (1-8.3% and 0.5-0.8%, respectively), whereas their diastereomers are significantly less abundant or entirely absent. Such esters are known natural products, [42][43][44][45] but none of the reported RIs matched, 46 suggesting the presence of previously unknown homologs. We estimated that the determined RIs would correlate well with (Z)-hex-3-en-1-yl eicosanoate (1), (Z)-hex-3-en-1-yl docosanoate (2) and geranyl heneicosanoate (3) and subsequently synthesized these three new natural products by simple Steglich esterification procedures.…”

“…e ID, identification method; RI, constituent identified by retention index matching with literature data, MS, constituent identified by mass-spectra comparison with those listed in the Wiley 11, NIST17, MassFinder 2.3 and a homemade mass spectral library, CoI, constituent identity confirmed by GC co-injection of an authentic sample, NMR, structure of the identified essential oil constituent was confirmed by 1D and 2D NMR analysis of chromatography fraction samples, DMDS, identification by derivatization with dimethyl disulfide. f Unidentified constituent: MS (EI), m/z (%) 97(10), 96 (100), 95(51), 81(12), 71(45), 68(8), 67(21), 66 (4), 65(10), 55(8), 53(7), 51 (4),43 (35), 41(20). g Relative stereochemistry was not determined.…”

Determination of Major, Minor and Chiral Components as Quality and Authenticity Markers of Rosa damascena Oil by GC-FID

“…Efforts have been made to identify valuable markers to guarantee rose oil quality and authenticity such as the content ratio of citronellol/geraniol, the enantiomeric excess of, e.g., rose oxides, linalool, citronellol and carvone, as well as the availability of trace substances such as β-damascenone, β-ionone and β-damascene [ 7 , 8 , 9 ]. High-resolution mass spectrometry (HRMS) has been applied to elucidate and allocate further potential components as quality markers; the identity verification of compounds, however, is still challenging and a limiting factor for their applicability as markers [ 10 ]. In addition to the identification of individual markers for authenticity control, more holistic approaches such as the study of isotope mass spectrometry to determine the δ13C values or enantio-multidimensional gas chromatography (MDGC) have been applied to identify fingerprints for rose oil origin [ 11 ].…”