Inulin hydrogels as carriers for colonic drug targeting: I. Synthesis and characterization of methacrylated inulin and hydrogel formation.

PURPOSE: Vinyl groups were introduced in inulin chains in order to form hydrogels of this sugar polymer by free radical polymerization. METHODS: Inulin was reacted with glycidyl methacrylate in N,N-dimethylformamide in the presence of 4-dimethylaminopyridine as catalyst. 1H and 13C NMR spectroscopy were used for the characterization of the obtained reaction product. Solid state 13C NMR spectroscopy revealed the conversion of the incorporated vinyl groups into covalent cross-links upon free radical polymerization of aqueous solutions of the derivatized inulin. RESULTS: During reaction of inulin with glycidyl methacrylate, transesterification occurred, leading to the direct attachment of the methacryloyl group to inulin. Consequently, the obtained reaction product is methacrylated inulin. The extent of chemical modification of inulin could be tuned by varying the molar ratio of glycidyl methacrylate to inulin in the reaction mixture. Aqueous solutions of methacrylated inulin were converted into cross-linked hydrogels by free radical polymerization using ammonium persulphate and N,N,N',N'-tetramethylethylenediamine as initiating system. CONCLUSIONS: Inulin hydrogels can be formed by free radical polymerization of aqueous solutions of methacrylated inulin.

Cannabiorci- and 8-chlorocannabiorcichromenic acid as fungal antagonists from Cylindrocarpon olidum.

Cannabiorcichromenic acid and 8-chlorocannabiorcichromenic acid [8-chloro-5-hydroxy-2,7-dimethyl-2-(4-methyl-3-pentenyl)-2H-1-benzopyran -6- carboxylic acid] were identified as active components in cultures of Cylindrocarpon olidum which antagonized various other fungi. Experiments performed with the purified acids confirmed the antifungal activity; in addition, they revealed that the acids had antibiotic properties towards gram-positive bacteria and were toxic to nematodes.

Two triterpenoid saponins from Heinsia crinata.

Two new triterpenoid saponins isolated from the root bark of Heinsia crinata were characterized as heinsiagenin A-3 beta-O-(beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl- (1-->6)-[alpha-L-rhamnopyranosyl-(1-->2)]-beta-D-glucopyranosyl-(1-->2)- beta-D-glucopyranoside) and heinsiagenin A-3 beta-O-(alpha-L-rhamnopyranosyl-(1-->2)-beta-D- glucopyranosyl-(1-->2)-beta-D-glucopyranoside). The structures were deduced mainly from a combination of 1- and 2D NMR experiments.

Synthesis and antiherpes virus activity of 1,5-anhydrohexitol nucleosides.

The synthesis of 1,5-anhydrohexitol nucleosides is described. These nucleoside analogues were obtained by alkylation of the heterocyclic bases with the tosylate 10 or by alkylation of the bases with the alcohol 12 under Mitsunobu conditions. The compounds were evaluated for antiviral and cytostatic activity. Highly selective activity against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) was noted for 1,5-anhydro-2,3-dideoxy-2-(5-iodouracil-1-yl)-D-arabino-hexitol 4b at a concentration of 0.07 microgram/mL. This activity must be dependent on a specific phosphorylation by the virus-encoded thymidine kinase (TK), since compound 4b was inactive against TK-deficient mutants of HSV-1. The corresponding cytosine 4c and guanine 4e analogues showed activity against HSV-1, HSV-2, and other herpes viruses (i.e. cytomegalovirus, varicella-zoster virus) at concentrations well below the cytotoxicity threshold (2 and 20 micrograms/mL, respectively). At these concentrations, compounds 4c and 4e proved also inhibitory to the growth of human T-cells (i.e. MT-4, CEM, MOLT-4).

By-products in the analysis of beta-muricholic acid in biological samples as methyl ester triacetate.

By-products were formed on analysis of beta-muricholic acid (3 alpha, 6 beta, 7 beta-trihydroxy-5 beta-cholan-24-oic acid) in biological samples by a method involving acid-catalyzed solvolysis of sulfate esters in acetone-methanol, followed by perchloric acid-catalyzed acetylation with acetic anhydride-acetic acid. These products have been identified by mass spectrometry and nuclear magnetic resonance as methyl 3-0,6-0-diacetyl-7-0-(1-methyl-3-oxo-1-butenyl)- and methyl 3-0,7-0-diacetyl-6-0-(1-methyl-3-oxo-1-butenyl)-beta-muricholate, methyl 3-0, 6-0-diacetyl- and methyl 3-0, 7-0-diacetyl-beta-muricholate, and a methyl diacetoxy-cholen-24-oate.

Structure of the side chain of the C29 dicarboxylic bile acid occurring in infants with coprostanic acidemia.

The structure of the side chain of the 3 alpha, 7 alpha, 12 alpha-trihydroxy-5 beta-C29 dicarboxylic bile acid occurring in body fluids of infants with coprostanic acidemia was investigated by means of mass spectrometry and nuclear magnetic resonance spectroscopy. The findings identified this bile acid as 3 alpha, 7 alpha, 12 alpha-trihydroxy-27a, 27b-dihomo-5 beta-cholestane-26,27b-dioic acid (3 alpha, 7 alpha, 12 alpha-trihydroxy-27-carboxymethyl-5 beta-cholestan-26-oic acid).

Naphthalene glycosides in Cassia senna and Cassia angustifolia.

From leaves and pods of Cassia senna L. and C. angustifolia Vahl. were isolated the naphthalene glycosides 6-hydroxymusizin glycoside and the new tinnevellin glycoside. The structures were established mainly by spectroscopic methods ( (1)H NMR, (13)C NMR, MS).