Intramolecular Cyclization During Bromination of the Quinoline Alkaloid Haplophyllidine.

Bromination of the furanoquinoline alkaloid haplophyllidine by molecular bromine and -bromosuccinimide was accompanied by intramolecular cyclization to form mixtures of new compounds containing additional penta-, hexa-, and spirocyclic rings incorporating the prenyl group of haplophyllidine. The structures and absolute configurations of the chiral centers of all four bromo-derivatives were elucidated using a combination of NMR spectroscopic methods and X-ray crystal structure analyses.

Rinderidine and oblongifolidine new pyrrolizidine alkaloids from M. Popov and their absolute configurations.

The alkaloid composition of was studied, in which the pyrrolizidine alkaloids echinatine and trachelanthamine N-oxide, as well as two new quaternary salts namely rinderidine and the oblongifolidine were isolated. The structures of the isolated new alkaloids were elucidated by NMR spectroscopy. The absolute configuration of lindelofine, trachelanthamine N-oxide, rinderidine and oblongifolidine was established by single crystal X-ray diffraction as: 1 , 4 , 8 , 2', 3'; 1 , 4, 8, 2', 3'; 4 , 7, 8 , 2', 3'; 4 , 7, 8 , 2', 3' (7'', 8'') respectively.

The structure and prebiotic activity of arabinogalactan from Ferula Kuhistаnica.

Acidic arabinogalactan with molecular weight 36 kDa was isolated from the aerial part of Ferula kuhistаnica, the monosaccharide composition of which is represented by galactose and arabinose in a ratio of 3.6:1. The chemical and spectral methods revealed a main polymer chain consisting of (1 → 6) β-galactopyranose residues, where in position of C-3 were the residues of α-arabinofuranose and its 1,5-linked oligomers, as well as β-GlcpA-4-OMe-(1 → 6)-β-Galp-(1→ fragments.

Guaianolides from (Kovalevsk.) Kovalevsk.

In continuation of our phytochemical study on the aerial part of (Kovalevsk.) Kovalevsk, three new guaiane-type sesquiterpene lactones were isolated namely karatanolide (), 11,13-dihydrokaratanolide () and 11,13-dihydrokaratanolide (), in addition to the two known sesquiterpene lactones 1,10-dihydroxyarglabin () and artefin (). The structures of the isolated sesquiterpene lactones were elucidated by IR and NMR spectroscopy.

Structure of arabinogalactan and pectin from the Silybum marianum.

From the leaves of Silybum marianum L. were isolated arabinogalactan with molecular weight 38 kDa and pectic substances. The monosaccharide composition of arabinogalactan was represented by β-galactose and α-arabinose in a ratio of 2.