## 4 Discussion  
According to the pharmacopoeial definition, the so-called Turkish galls, caused by _A. infectorius_, are greenish-brown to yellow-brown in color. Thus, both gall nuts with a hollow indicating that _A. infectorius_ larvae have left the gall nuts and also dried gall nuts with the remains of dead insects are classified as pharmacopoeial raw materials. For this reason, this study includes both gall nuts from the first harvest date, i.e., green without a hollow, and yellowish ones with a hollow. The minimum content of tannins expressed as pyrogallol, standardized for this raw material, is at least 20.0% [24], and it must be analyzed with the so-called hide powder method, using the spectrophotometric technique, for which the analytical procedure has been described in detail by the current \"European Pharmacopoeia\" and also the \"Polish Pharmacopoeia\" [19; 25]. Such a technique was used in this study. Meanwhile, most of the studies published so far, devoted to both _A. infectorius_ gall nuts and _C. quercusfolii_ galls, present the results obtained using analytical methods other than those recommended by the current pharmacopoeia [19; 25]. In [PERSON] et al. 's work [5], in which [PERSON]'s method was used, an average tannin content was found at the level of 81.4% for Turkish galls, and the results were also given for other herbal  
Figure 4: Chromatograms HPLC-DAD for samples of gall nuts _C. quercusfolii_ from three forest habitat types ((**A**) moist mixed broadleaved forest, (**B**) fresh broadleaved forest, (**C**) moist broadleaved forest) and gall nuts _A. infectorius_ ((**D**) first harvest date, (**E**) second harvest date). tannin raw materials, such as oak bark (_Quercus cortex_) and torrmentil (_Tormentilae rhizoma_), making it visible that the applied methodology overestimates the content of tannins by 2-3 times in relation to the results obtained for the hide powder method [36; 37]. In our study, the average tannin content expressed as pyroggallol was 34.77% for the first harvest date and 39.95% for the second harvest date. The minimum pharmacopoeial standard (20.0%) is, therefore, significantly exceeded for the tested raw material, which suggests the need to conduct more extensive studies on Turkish gall nuts and a possible revision of the pharmacopoeial monograph [25]. In this study, the composition of _A. infectorius_ gall nuts from Turkey using chromatographic and mass spectrometric techniques was compared with the composition of _C. quercusfolii_ gall nuts obtained from the Polish forest environment. Contrary to _A. infectorius_ gall nuts, the gall nuts of Central European oaks, formed as a result of leaf puncture by _C. quercusfolii_, have never been a pharmacopoeial material but have been widely used in folk medicine under the names of oak-galls, galls or oak apples. The indications for their therapeutic use were very broad and similar to those attributed to _A. infectorius_ galls, covering numerous diseases for which, in the light of modern medicine, tannins can be effective. These were skin diseases (in the form of squeezed juice) [38], diarrhea (in the form of a tincture) [39], wounds [40] and toothache [41]. The high efficiency of _C. quercusfolii_ gall nuts in folk medicine has attracted the attention of scientists for a long time. Already at the beginning of the 19 th century, the possibility of replacing Turkish gall nuts with native ones was suggested, noting its less effectiveness as a raw material but its common incidence and, therefore, easier and less expensive collecting practice [12]. However, only a few scientific papers were published devoted to _C. quercusfolii_ gall nuts as a possible alternative to _A. infectorius_ galls. Both [PERSON] [13; 14] and [PERSON] et al. [5] indicate their high potential usefulness in the pharmaceutical industry. On the other hand, [PERSON] et al. [15; 16] studied _C. quercusfolii_ gall nuts collected at various dates and of various sizes, with the raw material coming from mid-field trees.