A procedure for the determination of Phenolic compounds in extracts from the medicinal plants of the Lamiaceae family—garden sage (Salvia officinalis L.), creeping thyme (Thymus serpyllum L.), wild marjoram (Origanum vulgare L.), and common balm (Melissa officinalis L.)—obtained under different extraction conditions was developed. The identification of the extracted compounds was performed and their qualitative and quantitative composition was established by HPLC with diode array and mass-spectrometric detection with consideration for the obtained characteristics of the standard samples of individual components. The test samples of medicinal herbs contained caffeic acid (0.19–0.62 mg/g) and rosmaric acid (4–23 mg/g); the highest rosmaric acid content (23 mg/g) was found in wild marjoram, and the lowest content (4 mg/g), in creeping thyme. The extracts of wild marjoram contained the greatest amounts of Phenolic compounds; rosmaric acid and luteolin-7-O-β-D-glucuronide were major components, whereas protocatechuic, 3-O-caffeoylquinic, and caffeic acids were minor components.

The paper presents methods for the criteria for quality control, authenticity and stability of preparations and raw materials based on Hypericum perforatum L. and Salvia officinalis L. Various methods of extracting the most valuable components that make up the studied plants, as well as methods for their chromatographic determination, were proposed, metrological characteristics were obtained. • The criteria for quality control and stability of drugs and raw materials were substantiated • The ratio of rutin to hyperforin determines the quality of Hypericum perforatum L. • The ratio of carnosic acid to carnosol characterizes Salvia officinalis L.