Intramolecular Cyclization During Bromination of the Quinoline Alkaloid Haplophyllidine.

Bromination of the furanoquinoline alkaloid haplophyllidine by molecular bromine and N-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 Rindera oblongifolia M. Popov and their absolute configurations.

The alkaloid composition of Rindera oblongifolia 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 R, 4 R, 8 R, 2'S, 3'R; 1 R, 4S, 8S, 2'S, 3'R; 4 R, 7S, 8 R, 2'S, 3'S; 4 R, 7S, 8 R, 2'S, 3'S (7''S, 8''R) respectively. Both new pyrrolizidine alkaloids showed no cytotoxicity against four cancer cell lines such as HeLa, НEр-2, HBL-100 and CCRF-CEM.

Guaianolides from Tanacetopsis karataviensis (Kovalevsk.) Kovalevsk.

In continuation of our phytochemical study on the aerial part of Tanacetopsis karataviensis (Kovalevsk.) Kovalevsk, three new guaiane-type sesquiterpene lactones were isolated namely karatanolide (1), 11,13ß-dihydrokaratanolide (2) and 11,13α-dihydrokaratanolide (3), in addition to the two known sesquiterpene lactones 1ß,10α-dihydroxyarglabin (4) and artefin (5). The structures of the isolated sesquiterpene lactones were elucidated by IR and NMR spectroscopy. Single crystal X-ray diffraction allowed to unambiguously confirm the structure of the isolated sesquiterpene lactones. Quantum chemical calculations of the guaianolides 1-3 suggested the existence of two conformations for the seven-membered cycle. All sesquiterpene lactones from Tanacetopsis karataviensis were isolated for the first time.

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 â†’ 6) ß-galactopyranose residues, where in position of C-3 were the residues of α-arabinofuranose and its 1,5-linked oligomers, as well as ß-GlcpA-4-OMe-(1 â†’ 6)-ß-Galp-(1→ fragments. In addition, a small part of the main chain carries monosaccharide residues of ß-Galp-(1→ in position C-2. The effect of arabinogalactan on the growth of an associative culture of bifidobacteria and some mono-strains of lactobacilli was studied and it was shown that it exhibits more effective prebiotic activity.

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 ß-galactose and α-arabinose in a ratio of 2.6:1.0 and ß-galacturonic acid as a minor component. By chemical methods and GC, GC-MS, 1D and 2D NMR spectroscopy was established that the arabinogalactan consists of d-galactopyranose residues linked by ß-1,6-glycosidic bonds as a main chain, and the side chain was represented by α-arabinose, ß-galactose and 4-O-methylglucuronic acid. Pectic substance was found in small amounts. According to NMR data it contains also a branched rhamnogalacturonan.