The glucomannan system from Aloe vahombe (liliaceae). III. Comparative studies on the glucomannan components isolated from the leaves.

The polysaccharide mixture obtained by hot water extraction of Aloe vahombe leaves is composed of at least four different paritally acetylated glucomannans which differ in molecular weight, glucose to mannose ratios and acetyl contents. Furthermore, one fraction contains a small but significant amount of protein which could not be removed by gel filtration in a hydrogen-bond-breaking medium, by DEAE-Sephadex A-50 anion exchange chromatography, or by Sevag's method.

Further studies of the glucomannan from Aloe vahombe (liliaceae). II. Partial hydrolyses and NMR 13C studies.

The polysaccharide from Aloe vahombe (lilaceae) was submitted to partial hydrolyses by sulfuric, oxalic and phosphoric acid. Some oligosaccharides were isolated and investigated by chemical and 13C NMR spectroscopic methods. Their structure was determined.

A new enkephalin analogue: trans-4-hydroxycinnamoyl-glycyl-glycyl-phenylalanyl-leucine. Synthesis and biological properties.

A new analogue of the leucine-enkephalin in which the N-terminal tyrosine has been replaced by trans-4-hydroxycinnamic acid, has been synthetized by liquid-phase coupling methods. The central cardiovascular effects of this analogue were investigated and the results discussed.

A 400 MHz 1H NMR study of fortuitin, a natural linear lipopeptide.

Fortuitin is a linear acyl nonapeptide methyl ester in which all the peptide residues are hydrophobic. Its 400 MHz 1H NMR spectrum in pyridine-d5 has been assigned. In this solvent, its conformation is not random and seems to form a hairpin.

Rapid leucine-enkephalin synthesis.

Leucine-enkephalin, a naturally occurring pentapeptide with morphine-like activity, has been synthesized by a fragment condensation liquid phase method using 1,3,4-trimethyl-delta 3-phospholene-1,1-dichloride as a coupling agent. The advantages of this method are discussed.

Chemical and biological properties of a peptido-glucan fraction from Armillaria mellea (Basidiomycetes).

A peptide-glucan fraction from Armillaria mellea (Basidiomycetes) was isolated and some aspects of its chemical structure were determined. The glucan is linked to the peptide portion which represents 30% w/w of the complex. Treatment with alkali destroys most of the threonine and leads to the separation of the peptide and carbohydrate moieties indicating the involvement of the hydroxyl group of threonine in the peptide-glucan linkage.

Immune response to sheep red blood cells in mice pretreated with mycobacterial fractions.

Ten micrograms of trehalose-6,6' -dimycolate (cord factor) injected into the footpads of mice increased the antibody response to sheep red blood cells (SRBC) subsequently injected into the same sites. There is a relationship between the antibody response and the cellular reaction induced locally and in the draining lymph nodes by cord factor, as judged by a much weaker response when antigen is injected into the contralateral footpads. The time intervals between injection of cord factor and antigen were from 5 to 20 days.

Cellular reaction in the footpad and draining lymph nodes of mice induced by mycobacterial fractions and BCG bacilli.

Ten micrograms of trehalose-6, 6'-dimycolate (cord factor), injected into the footpad of mice, induced histological changes similar to those following injection of living BCG bacilli. Both materials induced in the draining lymph nodes the formation of granulomas composed of epitheloid cells, macrophages, and small numbers of lymphocytes. Apart from the granulomatous inflammatory process, marked hyperplasia of the lymphoid tissue in the paracortical zone of the nodes and accumulations of macrophages were evident.

Granuloma formation induced in mice by chemically defined mycobacterial fractions.

Amounts of trehalose-6,6-dimycolate as small as 1 to 5 mug can, after intravenous injection, induce in the lungs of mice formation of tubercles in which the cellular composition is indistinguishable from that in tubercles formed after an infection with living BCG bacilli. The strongest cellular response in mice was induced by cord factor from Mycobacterium kansasii; the weakest was induced by cord factor from the BCG strain of M. bovis.