Secondary metabolites of selected taxa of the genus bupleurum L. (apiaceae): isolation, identification and biological activity

[M. Nešić]

257 listova

Biografija: list. 251. Bibliografija: list. 174-188.

Organic chemistry and biochemistry, organic synthesis

In this doctoral dissertation, a phytochemical study of the secondary metabolites of selected species of the genus Bupleurum L. (Apiaceae) was undertaken with the goals of isolating, identifying and evaluating the biological activity of the less-polar metabolites. The study encompassed a detailed chemical investigation of diethyl-ether extracts of B. praealtum, B. veronense, B. falcatum and B. sibthorpianum, as well as the essential oils of B. praealtum and B. affine. Using dry-flash chromatography, GC–MS analysis and NMR spectroscopy, sixteen new compounds were isolated and structurally characterized. These include a large cohort of polyunsaturated metabolites—a hydrocarbon, several esters, a γ-butyrolactone and a macrolide—together with one lignan and one phloroglucinol derivative. In the extract of B. praealtum, four new polyunsaturated esters, a new polyunsaturated γ-butyrolactone and one new lignan, 7-oxoarctin, were identified. From B. veronense, a new macrolide (homodihydrofalcarinolide), a polyunsaturated veronaester and a phloroglucinol derivative were obtained. In B. falcatum and B. sibthorpianum, three new polyunsaturated aliphatic esters and one new polyunsaturated hydrocarbon were detected. The essential oils of B. praealtum and B. affine were analyzed by GC–MS, revealing a total of 230 constituents. Sesquiterpene hydrocarbons predominated in both oils, while the oil of B. affine was also notable for a high content of alkanes. For the first time, perillyl 2-methyl-butanoate (its identity confirmed by synthesis) was detected, along with two new natural acetate esters—4-decyl acetate and 4-undecyl acetate. Selected compounds were assayed against primary rat immune cells (macrophages and splenocytes). They displayed concentration-dependent, bidirectional activity with marked immunomodulatory selectivity. These findings broaden current knowledge of the chemical diversity within Bupleurum, underscoring its taxonomic and pharmacological potential.

Bupleurum, ekstrakt, etarsko ulje, polinezasićeni estri, lignani, makrolid, floroglucinol, spinska simulacija, NMR, GC-MS, hromatografija, Mosher-ovi estri

Bupleurum, extract, essential oil, polyunsaturated esters, lignans, macrolide, phloroglucinol, spin simulation, NMR, GC-MS, chromatography, Mosher’s esters

(582.794.1:577.13):(54.061+615.322)(043.3) 577.121:582.321.2(043.3)

P 003; P 004; P 390; P 300

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