## 3 Results and Discussion
### Identification of Flavonoids in Fig Leaves
As shown in Figure 6, flavonoid glycosides mainly underwent Y\({}^{-}\) type cleavage; that is, the glycosyl is removed, and the hydroxy is retained, which is represented by Y\({}^{-}\). The right subscript of the ion indicates the type of glycosyl. For example, Y\({}_{\rm H^{-}}\) means the cleavage of the hexose to remove the glycosyl. Flavonoid glycosides mainly underwent the cleavage of the sugar ring (X cleavage). When cleavage occurs, the position of the broken bond on the sugar ring is indicated by the left superscript, and the type of the cleavage glycosyl is indicated by the right subscript. This included hexose (H), pentose (\(p\)), and deoxyhexacarbonose (D). For example, 0.2X\({}_{\rm H}\) represents a ring-opening cleavage caused by the breakage of the 0, 2 bond on the hexose [36; 37]. Compounds **1**, **2**, **7**, **10**, and **11** were all flavonoid oxygen glycosic compounds [38]. Quasi-molecular ion peaks can appear in negative ion modes of flavonoid oxygen glycosic compounds to cause glycosidic bond cleavage. This is characterized by a neutral loss of the glucosyl C\({}_{6}\)H\({}_{10}\)O\({}_{5}\) (162), rhamnosyl C\({}_{6}\)H\({}_{10}\)O\({}_{4}\) (146), or xylose C\({}_{5}\)H\({}_{8}\)O\({}_{4}\) (132). The aglycon structure can continue to lose -CH\({}_{3}\) and -CO\({}_{2}\) or RDA cleavage can occur in the C ring of the flavonoid aglycon. The MS spectrum of Compound **1** (t\({}_{\rm R}\) = 10.22 min) showed an [M - H]\({}^{-}\) ion at \(m/z\) 771.2027, and the fragment ions of oxygen glycosides: \(m/z\) 609.1530, 462.0838, and 301.0357 were generated. Compound **1** was identified as quercetin 3-O-hexobioside-7-O-hexoside [39]. Compound **10** (t\({}_{\rm R}\) = 14.34 min) showed an [M - H]\({}^{-}\) ion at \(m/z\) 463.0890. According to \(m/z\) 301 [M-162-H]\({}^{-}\) secondary mass spectrometry, we speculated that there was glucose in the structure of the compound, and the molecular weight of the parent nucleus was 301, which was quercetin. Based on Scifinder and Reaxy database retrieval, Compound **10** was presumed to be quercetin 3-O-hexoside [40]. Compound **1** and Compound **10** had the same mass spectrum fragmentation pathway. The relative molecular mass of Compound **10** was 464. The fragment ion peak (\(m/z\) 301) was caused by the loss of a quasi-molecular ion peak and a neutral fragment of \(m/z\) 162. According to the relative molecular mass, the neutral fragment of \(m/z\) 162 was preliminarily judged to be a glucose group. Since [M-H-162]\({}^{-}\) (\(m/z\) 301) is a fragment ion of quercetin glycone, this indicates that there was a glucosyl group in the compound. The fragmentation of \(m/z\) 301 ion generated two main characteristic ions: \(m/z\) 179 and \(m/z\) 151. The \(m/z\) 179 may be obtained by the fragmentation of \(m/z\) 301 and the transfer of 2 H ions. The \(m/z\) 151 fragment ion was generated by the RDA reaction of \(m/z\) 301. In addition, the loss of one molecule of CO at \(m/z\) 179 also generated \(m/z\) 151 ions. This is consistent with the cleavage pathway for quercetin 3-O-hexobioside quercetin aglycon fragment ions, and the cleavage law conformed to the structural characteristics of quercetin 3-O-hexoside. Compound **2** (t\({}_{\rm R}\) = 11.59 min) showed an [M - H]\({}^{-}\) at \(m/z\) 365.0881 and product ions at \(m/z\) 203.0352, 159.0454, and 130.0422. Among them, \(m/z\) 203.0352 represented [M-H-C\({}_{6}\)H\({}_{10}\)O\({}_{5}\)]\({}^{-}\) obtained after the precursor ion lost glucose, which is the aglycon of the compound. The \(m/z\) 159.0454 represents the fragment ion obtained after the precursor ion  
Figure 6: Mass spectrometric analysis of flavonoid glycosides in negative ion mode. had lost 206 Da [M-C\({}_{11}\)H\({}_{10}\)O\({}_{4}\)+H]\({}^{-}\). The \(m/z\) 130.0422 represents the fragment ion obtained after the precursor ion had lost 235 Da [M-C\({}_{12}\)H\({}_{11}\)O\({}_{5}\)-H]\({}^{-}\).