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ORAL PRESENTATION / SÖZLÜ SUNUM

Optimization of Ultrasound-Assisted Extraction of Thymbra Spicata
Using Response Surface Metrology: Polyphenol Profile and Antibacterial Activity

Muhammed Hasan ŞİRİN 1,2,* Muhammet Mükerrem KAYA Melike Sultan DEMİRAĞ
3
3
Erhan KEYVAN Murat BAYEZİT Hidayet TUTUN 3
3
4

1 Siirt University, Faculty of Veterinary Medicine, Department of Pharmacology and
Toxicology, Siirt, TÜRKIYE
2 Ankara University, Graduate School of Health Sciences, Department of Pharmacology and
Toxicology, TÜRKIYE
3 Burdur Mehmet Akif Ersoy University, Faculty of Veterinary Medicine, Department of
Pharmacology and Toxicology, Burdur, TÜRKIYE
4 Burdur Mehmet Akif Ersoy University, Faculty of Veterinary Medicine, Department of Food
Hygiene and Technology, Burdur, TÜRKIYE

*Correspound Author: mhasan.srn@gmail.com

Thymbra spicata (Zahter) is an aromatic plant that grows naturally in Türkiye and is
widely used in traditional medicine. This study aimed to optimize ultrasound-assisted
extraction (UAE) conditions using Response Surface Methodology (RSM) to obtain total
phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity (DPPH) from T.
spicata. The TPC, TFC, and DPPH scavenging capacity of the extract obtained under optimal
conditions, as well as its polyphenolic profile (LC-MS/MS) and antibacterial activity
(Microdilution), were determined. The determined optimum conditions were: solvent
concentration (methanol/water) 31.071%, temperature 63.467 °C, extraction time 48.423
minutes, and solvent/solid ratio 36.144 ml/g. TPC, TFC and DPPH values of the optimum
extract were found to be 145.77±2.256 mg GAE/g, 16.19±0.196 mg QE/g and
97.794±1.784 mg AAE/g, respectively. In addition, a high level of positive correlation was
determined between the dependent variables (TPC-DPPH 0.73; TPC-TFC 0.92; TFC-DPPH
0.8). Among the polyphenols investigated in the optimum extract, the highest levels of
Gentisic acid and Salicylic acid were detected. The minimum inhibitory concentration (MIC)
for Salmonella Typhimurium and Listeria monocytogenes was found to be 5 mg/mL and the
minimum bactericidal concentration (MBC) was 10 mg/mL. MIC and MBC values for
Escherichia coli O157:H7 were detected as >10 mg/mL. In conclusion, it was determined
that T. spicata is a rich source of bioactive compounds, and the polyphenolic-rich extract
optimized with RSM exhibited high concentrations of antibacterial activity.
Keywords: Antibacterial activity, Antioxidant activity, Thymbra spicata, Ultrasound-assisted
extraction, Response Surface Methodology.

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