Chemical composition analysis of bitter water rose alcohol extract based on UPLC-Q-TOF-MS
Rose (Rosa rugose Thunb) is an evergreen or deciduous shrub of the Rosaceae family, and is planted in various parts of the country. Famous varieties include Shandong Pingyin Rose, Gansu Kushui Rose, Beijing Miaofengshan Rose, etc. Among them, Rosa sertata × Rosa rugosa is a natural hybrid of Chinese rose and Rosa obtusifolia, which has the effects of helping sleep, anti anxiety, etc., and the rose oil extracted from the petals can also be used as an important raw material for advanced essence, perfume, perfume and cosmetics, which is closely related to its chemical composition. Previous studies have shown that there are over a hundred chemical components in roses, mainly including volatile oils, flavonoids, polyphenols, polysaccharides, and other compounds. The volatile oil is the main class of compounds in rose essential oil, mainly containing chemical components such as citronellol and geraniol. Polyphenols and flavonoids are the main active ingredients of roses, which have the functions of clearing free radicals and pigment deposition, and are important antioxidant substances.

At present, there are many studies on the chemical composition of volatile oils in rose essential oil, but the analysis of flavonoids, polyphenols, and other compounds in roses is not yet complete, and there are few reports on the chemical composition of bitter water rose varieties. Therefore, in this study, the ultra-high performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) technique with high sensitivity, selectivity, stability, resolution, and wide scanning range was used to analyze and identify 63 main chemical components from the ethanol extract of Rosa rugosa. Compared with previous studies, this study further improved the chemical composition identification of flavonoids and polyphenols in bitter water roses, and for the first time, 28 compounds were identified in this genus, providing reference and theoretical basis for the quality control and pharmacological substance basis research of bitter water roses.

 

 

This study uses UPLC-Q-TOF-MS technology, which has the characteristics of high sensitivity, high accuracy, and high resolution, and can more comprehensively and quickly identify the chemical components of bitter water roses. Our research group investigated the mass spectrometry peaks and ion responses of rose water extract and alcohol extract under negative ion mode before the study. Based on the peak analysis, it was found that the alcohol extract of rose water had good separation and high response in the (-) ESI-MS mass spectrometry ion chromatogram. Therefore, UPLC-Q-TOF-MS was used to systematically analyze the chemical components in the alcohol extract of rose water, further improving the identification of the chemical components of rose water.
This study identified 26 flavonoids, 11 polyphenols (including 4 phenolic acids and 7 tannins), 7 triterpenoids, 4 phenylpropanoids, 1 cyclohexene ether terpene, 1 volatile oil, and 8 organic acid compounds from the alcohol extract of bitter water rose. Among them, phenolic acids, tannins, and flavonoids are its main active ingredients. The results show that the identified flavonoids are mainly composed of compounds with quercetin and kaempferol as aglycones, which is similar to the previous identification results. The four identified phenolic acid compounds all belong to the gallic acid class and have the effects of drying dampness, astringency, clearing heat and reducing inflammation, cooling blood and stopping bleeding. Tannin compounds, except for compounds 16 and 17, are also gallic acid tannins, which have pharmacological activities such as anti-tumor and antioxidant effects, along with flavonoids. Moreover, polyphenolic compounds have high response values in mass spectrometry, once again proving that bitter water roses have excellent antioxidant and anti-tumor effects. According to literature reports, roses also contain pigment compounds such as cyanidin-3,5-diglucoside, delphinidin-3-glucoside, etc. However, this was not identified in the results of this study, which may be related to the treatment or liquid quality conditions of bitter water roses and requires further research. And it was also found from the TIC diagram of the negative ion mode of the bitter water rose that some compounds with high response peaks could not be accurately identified due to the unreasonable structural formulas matched by the online database, such as peaks 10, 14, 21, 24, and 43, indicating that there are still some unknown compounds in the bitter water rose, which may be the main components of the bitter water rose and need further research and analysis.
This study established a rapid analysis method using UPLC-Q-TOF-MS technology for bitter water roses. Based on accurate relative molecular weight, mass spectrometry fragment information, and relevant literature and databases, the chemical composition of bitter water roses was analyzed and identified more comprehensively. 58 compounds were identified, of which 28 compounds were identified for the first time from this genus. This provides a reference and scientific basis for the basic research on the pharmacological effects and active ingredients of bitter water roses.