## 4 Discussion
At the same time, a differentiated content of tannins, ranging from 10.0% to 15.8% expressed as pyroggallol, was demonstrated, and it was emphasized that _C. quercusfolii_ gall nuts are the richest Central European tannin material [24]. In this study, it was found that the average content of tannins expressed as pyroggallol, depending on the three habitat types of forest, differs significantly and ranges from 13.36% for the moist mixed broadleaved forest to 14.74% for the moist broadleaved forest. However, the values for all three forest sites confirm the previous study results, which place _C. quercusfolii_ gall nuts as the richest tannin raw material that could be obtained in Central Europe [15; 24]. However, a comparison of their qualitative composition, determined on the basis of HPLC-DAD-MS (\"fingerprint\") chromatographic profiles, shows significant differences with _A. infectorius_ gall nuts (Figures 3 and 5). Further, the total tannin content in _A. infectorius_ gall nuts is two to three times higher, which is indicated, in turn, by a study performed with the hide powder method using spectrophotometric techniques. Figure 5: List of chromatograms obtained during the HPLC-DAD analysis for _C. quercusfolii_ gall nut samples, green, and _A. infectorius_, blue. Similar to the results obtained with the hide powder method, also comparing the total ion mass distribution profiles (direct injection of the sample to the MS detector) of _C. quercusfolii_ gall nuts (Polish galls) with _A. infectorius_ gall nuts (Turkish galls), it can be concluded that Turkish gall nuts are a valuable source of tannins (mainly galloyl glucoses), while Polish gall nuts contain much less of them, including gallic acid (Figures 2 and 3). The most important thing is, however, that the obtained results (hide powder method, HPLC-DAD-MS SCAN) clearly show that Polish gall nuts contain much fewer tannin compounds compared to the composition of Turkish galls. Thus, both the composition and the total tannin content indicate that _C. quercusfolii_ gall nuts cannot be a substitute for _A. infectorius_ galls but still remain a very valuable and the richest tannin raw material in this part of Europe. For this reason, the potential use of gall nuts may be analogous to that of other tanning-rich raw materials, e.g., tormentil, oak bark or raspberry leaf. The European Medicines Agency has approved the traditional use of herbal medicinal products from these raw materials, including in the form of commitment/powdered herbal substances or tinctures. Regardless of the differences in the total tannin content and in their qualitative composition, they have analogous therapeutic indications, i.e., \"symptomatic treatment of minor inflammations of the oral mucosa\"; such pharmaceutical forms and therapeutic indications could also refer to the galls of _C. quercusfolii_. The registration of such herbal medicinal products would be easier if quality criteria were introduced in the current \"European Pharmacopoeia\" in the form of a pharmacopoeiai monograph. The standards for the content of tannins in the gall nuts of _C. quercusfolii_, as well as the identification by mass spectrometry technique presented in this paper, could form the basis for its development.