Metabolites profiling of Egyptian Rosa damascena Mill. flowers as analyzed via ultra-high-performance liquid chromatography-mass spectrometry and solid-phase microextraction gas chromatography-mass spectrometry in relation to its anti-collagenase skin effect

Rosa damascena Mill. is well recognized for its value as an ornamental aromatic plant with several folk medicinal uses. As a valuable oil-bearing plant, its aroma profile was extensively studied, albeit differences between unexpanded rose flowers (URF) and expanded rose flowers (EFR) at different levels of blooming is not reported. Rose scent from both stages was determined using headspace solid-phase microextraction (HS-SPME) for the first time for Egyptian rose. A total of 75 volatiles were detected, with alcohols, esters, and oxides as valuable volatile classes at ca. 64 %, 10 % and 2 % respectively in ERF compared to 46 %, 2 %, and 0.4 % in URF. Egyptian rose aroma is considered of high quality being enriched in citronellol, geraniol, and phenylethyl alcohol (rose oil). Total flavonoids, phenolics, and anthocyanins were found more enriched in ERF than URF. Further, comprehensive ultra-high-performance liquid chromatography/photodiode array detector/electrospray ionization-mass spectrometry UHPLC/PDA/ESI-MS revealed 66 secondary metabolites, of which sphingolipid conjugates and tannins are first time to be reported in rose including several novel phenolics viz., gallic acid-di-O-hexoside, galloyl hexose malic acid I, digalloyl-hexosyl-ellagic acid and levoglucosangallate I. Further, in-vitro anti collagenase assay revealed a strong effect for ERF compared to URF and in correlation to its metabolite fingerprint. The strong fragrant scent of Egyptian rose along with its anti-collagenase effect poses it for incorporation in cosmetics and skincare products.