## 3 Results and Discussions
### HPLC-MS Analysis of Phenolic Compounds
However, during sprouting, it increased by 11 times after 3 days, and by 15 times after 7 days (Table 4), reaching a content of 558.47 ug/g dw. It has been shown that the rutin content of leaves, not flowers, can vary during sprouting, depending on the level of intensity of UV radiation--being lower when the radiation intensity is lower [48]. For example, [PERSON] et al. [49] recorded a 19-fold increase in rutin content after 7 days of sprouting. In buckwheat achenes, the highest concentrations of flavonoids were represented by quercetin arabinoside (299.19 ug/g sample) and quercetin (quercetin-3-O-Hammoside; 227.04 ug/g dw)--much higher amounts compared to the variety of buckwheat (undetectable) from the study conducted by [PERSON] et al. [50]. From Table 4 and Figure 3, it can be seen that the quercitrin content reached a maximum on the third day, after which it decreased, so that on the seventh day it was undetectable. The quercetin content showed a 2.3-fold increase after 3 days of sprouting, compared to the results obtained by [PERSON] et al. (increased by 1.61 times) [8]. After 7 days of sprouting, there was an increase of 3.8 times. Knowing the numerous pharmacological actions of quercetin [51], it is possible to assess the maximum level of quercetin content in natural products so that it can be used successfully in various diseases; for example, in recent studies that highlight its antiviral action in SARS-Cov2 infections [52; 53; 54]. Even in smaller quantities, the flavonoids isorhametin (130.83 ug/g dwb) and isorhametin glucuronide (39.23 ug/g dwb) showed significant increases after seven days of sprouting--by five times (isorhametin) and ten times (glucuronide), respectively. The identification and quantification of these two flavonoids is important in terms of the multiple pharmacological effects that they have: antioxidative, anti-atherosclerotic, myocardial and endothelial protective [55; 56; 57; 58; 59; 60]. In buckwheat achenes there were three flavanols identified: EGC, EGCG and GCG, whose concentrations gradually decreased, so that on the seventh day of sprouting, only 85.55 ug/g dwb of EGC remained. Rhubarb is from the same family as buckwheat, and contains 3.3 ug/g dwb epicatechin [61]. [PERSON] and [PERSON] [62] showed in their study a decrease in epicatechin content in rhubarb stems and leaves during plant development. In contrast, the concentration of catechins from 108.97 ug/g dwb in buckwheat achenes increased to 170 ug/g dwb in sprouted buckwheat. The same evolution of catechin concentration has been previously reported by [PERSON] et al. [63]. Studies have shown that the antioxidant activity given by flavanols would be higher than that given rutin [64], and lower than that given by quercetin--although it works for a longer period of time. Lignans belong to the group of diphenic compounds derived from the biosynthetic pathway of shikimic acid [65]. In buckwheat achenes there were seciosolaricresinol and hydroxiseoisolariciresinol, identified in quantities of 323.51 ug/g dwb and 886.70 ug/g dwb, respectively--compounds with antiestrogenic, antioxidant and anticarcinogenic properties [65]. Coumestrol, a natural organic compound of the coumestans class, is classified as a phytoestrogen because it has actions similar to those of estradiol [66]. In buckwheat achenes we determined a concentration of 34.47 ug/g dwb. After 7 days of sprouting, its concentration increased by 27-fold, reaching 917.71 55 ug/g dwb.