Comparative analysis of biologically active compounds in Tagetes patula L. and Tagetes erecta L.
Аннотация
The aim. The aim of this study was to conduct a comparative analysis of biologically active compounds accumulated in two species – Tagetes patula L. and Tagetes erecta L. – in order to identify the most promising plant material for pharmaceutical development. The research focused on evaluating the qualitative and quantitative composition of free amino acids, water-soluble vitamins, flavonoids, and polysaccharides, as well as assessing their structural characteristics using titrimetric and phytochemical methods. Methods. Plant raw materials consisting of inflorescences (flowers) of Tagetes patula L. and Tagetes erecta L., collected during the flowering period, were used for analysis. Free amino acids were identified and quantified using chromatographic methods. Water-soluble vitamins were determined spectrophotometrically. The flavonoid profile was established through chromatographic identification of dihydroquercetin, luteolin, rutin, rosavin, quercetin, salidroside, and cynaroside. Polysaccharides, pectic substances, and hemicelluloses were isolated, and their monosaccharide composition was assessed. Titrimetric analysis was used to determine free and methoxylated carboxyl groups and to calculate the degree of esterification of pectic substances. Comparative evaluation between the two species was carried out for all analyzed parameters. Results. A total of 20 free amino acids were identified in both species, including eight essential amino acids. The total amino acid content was significantly higher in T. patula (57.053 mg/g) compared with T. erecta (38.020 mg/g). Both species contained equivalent qualitative sets of water-soluble vitamins–thiamine, riboflavin, pyridoxine, folic, nicotinic, and ascorbic acids–while T. patula demonstrated considerably higher quantitative levels. The flavonoid composition of both species was identical qualitatively; however, the total flavonoid content was markedly higher in T. patula. Polysaccharide analysis showed that pectic substances and hemicelluloses predominated in both species, with lower levels of water-soluble polysaccharides. The degree of esterification indicated highly esterified pectins, with T. patula containing higher levels of both free and methoxylated carboxyl groups. Discussion. The results indicate that Tagetes patula L. contains substantially higher quantities of key biologically active substances–including amino acids, vitamins, flavonoids, and structurally active polysaccharides–compared to Tagetes erecta L. The richer phytochemical profile of T. patula supports its greater pharmacological potential, including anti-inflammatory, antioxidant, antimicrobial, gastroprotective, and anthelmintic properties traditionally attributed to Tagetes species. Structural analysis of polysaccharides further demonstrates their suitability for use as bioactive excipients in dosage forms. Conclusions. Comparative phytochemical evaluation of Tagetes patula L. and Tagetes erecta L. demonstrated that T. patula accumulates significantly higher levels of biologically active compounds. Based on the obtained data, Tagetes patula L. can be considered the optimal species for use as medicinal plant raw material in the development of modern phytopharmaceuticals with pronounced therapeutic activity