Green extraction of Quercus infectoria gall with supercritical CO2 and methanol co-solvent

Abstract

A comparative study of phenolic acid extract from Quercus infectoria Gall using supercritical uid extraction of CO 2 (SCFE-CO 2 ) with co-solvent methanol can produce yields, phenolic acid compositions, and differences in the extract's toxicity. SCFE-CO 2 was carried out with the same weight of material (Q. infectoria gall) and run at a temperature of 60 o C and a pressure of 20 MPa with methanol as the cosolvent and an extraction time of 60 minutes. The extraction process extracts were identi ed by yield, phenolic acid composition using LC-MS/MS, total phenolic acid, and toxicity. The results of the SCFE-CO 2 extraction technique with co-solvent methanol do not produce extracts that are toxic but have high yields and tannic acid compound (TPC). The SCFE-CO 2 technique has small extract variability (div. sd. 0.1%), a high yield, a high tannic acid compound, a high TPC, and non-toxic, so SCFE produces extracts that have maintainable quality. The small amount of addition of methanol co-solvent can increase the quality of the extract using the SCFE-CO 2 technique, and increasing the addition of methanol cannot increase yield.

Phytochemical Profiling and Biological Activities of Quercus sp. Galls (Oak Galls): A Systematic Review of Studies Published in the Last 5 Years

“…Regarding the oak gall samples, their preparation before the extraction of phenolic compounds consisted of cleaning, drying, and grinding. The cleaning of the gall samples was performed with washing [8,43], some studies using tap water [19], and others boiling water [9]. The galls were air-dried at room temperature [19,43], in the shade [8,20] or in an oven at 40-45 • C for approximately 24 h [9,21].…”

“…The cleaning of the gall samples was performed with washing [8,43], some studies using tap water [19], and others boiling water [9]. The galls were air-dried at room temperature [19,43], in the shade [8,20] or in an oven at 40-45 • C for approximately 24 h [9,21]. For the coarse grinding of the plant material, either grinding the galls in a disc mill [51] or crushing the galls in a mortar with a pestle [8,43] was used.…”

“…Historically, Quercus sp. galls have been used for millennia in both Western and Eastern cultures as traditional remedies to treat inflammatory conditions, including diarrhea and dysentery, stomach aches, toothaches, and tooth decay, as well as in postpartum care, in combating metabolic abnormalities and oxidative stress-related diseases [1,6,9,10]. In Plants 2023, 12, 3873 2 of 48 addition to medicinal use, the industrial use of Quercus sp.…”

“…Pharmacologically, Quercus sp. galls have been reported to possess strong antibacterial, antioxidant, and anti-inflammatory activities, and also antitumor, antifungal, antiviral, antiprotozoal, antiamoebic, antiulcer, larvicidal, tooth and gum tonic, antipyretic, analgesic/local anesthetic, antidiabetic, cardioprotective, hepatoprotective, antiparkinsonian, antitremor, and accelerated wound healing effects [1,3,4,8,9,11,12]. Despite the multiple therapeutic properties, the long-term intake of gallnuts in high doses is not recommended.…”

“…Compared to other galls, the galls of the genus Quercus stand out for the highest level of tannins (50-70%) [1,4]. In addition to tannins, the diverse phenolic profile mainly includes numerous flavonoids and simple phenolic compounds, such as phenolic acids, hydroxyphenols and coumarins, and in a smaller number, representatives from other groups of phenolic compounds, i.e., phenolic aldehydes, naphthodianthrones, acyl-phloroglucinols, phenolic alcohols, and stilbenes [9,10,[18][19][20][21].…”