Carl F. Albrecht

Beta-sitosterol and beta-sitosterol glucoside stimulate human peripheral blood lymphocyte proliferation : implications for their use as an immunomodulatory vitamin combination

The phytosterols, beta-sitosterol (BSS), and its glucoside (BSSG) enhance the in vitro proliferative response of T-cells stimulated by sub-optimal concentrations of phytohaemagglutinin (PHA) several fold at extremely low concentrations (femtogram level). A 100:1 (mass:mass) ratio of BSS:BSSG (termed essential sterolin formulation, ESF) showed higher stimulation than the individual sterols at the same concentration. In vivo activity of ESF was also demonstrated when volunteers ingested ESF for 4 weeks. Proliferation of their T-cells, stimulated maximally with PHA, was significantly enhanced (20-920%) when compared to baseline values. In vitro, ESF (1 microgram.ml) was able to significantly enhance the expression of CD25 and HLA-Dr activation antigens on T-cells and increased the secretion, into the medium, of IL-2 and gamma interferon. NK-cell activity was also increased by BSS and BSSG alone, but with EST a higher activity was always found at different effector:target ratios (100:1 12:1).

Bioactive alkaloids from Brunsvigia radulosa.

A phytochemical investigation of the bulbs of Brunsvigia radulosa yielded the new alkaloid 1-O-acetylnorpluviine, together with the known structures 1-epideacetylbowdensine, crinamine, crinine, hamayne, lycorine, anhydrolycorin-6-one and sternbergine. All structures were established by spectroscopic evidence. Some of the 13C assignments which were reported for crinamine and hamayne were corrected by means of 2D NMR techniques. In order to provide a further structure for biological testing, crinamine was converted to apohaemanthamine. The alkaloids were tested for activity against two strains of cultured Plasmodium falciparum and for cytotoxicity with BL6 mouse melanoma cells.

Alkaloids from Crinum delagoense

Abstract Six alkaloids have been isolated from fresh bulbs of Crinum delagoense . The alkaloids, delagoensine and delagoenine, are reported here for the first time. The structure and stereochemistry of the new alkaloids have been determined by physical and spectroscopic methods. 1 H and 13 C NMR spectra were completely assigned by means of 2D NMR techniques.

EFFECT OF ROOPEROL ON COLLAGEN SYNTHESIS AND CELL GROWTH

The effect of rooperol on type I collagen synthesis in normal skin and lung fibroblasts and cell growth in normal and transformed fibroblasts was investigated. Low concentrations of rooperol selectively inhibited the growth of transformed cells while stimulating collagen synthesis in normal fibroblasts. Elevated collagen synthesis and deposition could impede tumour cell invasion and metastasis, implying that rooperol may be useful as an antimetastatic agent in the treatment of cancer.

Triterpenoid saponins from Becium Grandiflorum var. obovatum

Two new triterpenoid saponins, beciumecine 1 and 2, were isolated from the root bark of Becium grandiflorum var. obovatum and their structures established as 3-O-(beta-D-glucopyranosyl) terminolic acid 28-O-beta-D-apiofuranosyl(1-3)-[alpha-L-rhamnopyranosyl (1-3)-beta-D-xylopyranosyl(1-4)]-alpha-L-rhamnopyranosyl (1-2)-alpha-L-arabinopyranoside and 3-O-(beta-D-glucopyranosyl) 24-hydroxyterminolic acid 28-O-alpha-L-rhamnopyranosyl(1-3)-beta-D-xylopyranosyl(1-4)-alpha-L- rhamnopyranosyl(1-2)-alpha-L-arabinopyranoside, respectively.

Detection of 3-hydroxy-3-methyloxindole in human urine☆

During routine toxicological screening of urine for possible drug overdose, using two-dimensional thin-layer chromatography, an unknown substance was periodically detected that could not be related to any known drug. The substance was mass-isolated from the urine of a schizophrenic patient, who excreted it prolifically and it was chemically identified as 3-hydroxy-3-methyloxindole by mass spectrometry and 1H- and 13C-NMR. The structure was confirmed by synthesis through methylation of isatin. This is the first report associating 3-hydroxy-3-methyloxindole with human biochemistry. It is thought that this substance is an in vivo oxidation product of 3-methylindole which is a metabolic product of tryptophan, produced by bacteria in the colon.

Erythropoietin production in anemia associated with experimental cancer

Serum erythropoietin (EPO) concentrations reportedly are depressed in patients with chronic disorders such as cancer, rheumatoid arthritis, and acquired immunodeficiency syndrome. We evaluated serum EPO levels in mice with tumors and found that the EPO response was appropriate for the associated anemia during the major part of the disease process. The levels of the hormone increased as the anemia worsened in association with progression of the disease. The increased EPO levels were comparable to those of controls with a similar degree of experimentally induced anemia. Only during the terminal stages of cancer, when the animals were severely cachectic, were serum EPO concentrations lower than in controls with a similar degree of anemia. These findings suggest that a blunted EPO response in experimental cancer occurs only in association with advanced disease.

Isolation and structure elucidation of xanthotoxin, a phototoxic furanocoumarin, from Peucedanum galbanum

The major vesicant principal of Peucedanum galbanum has been isolated for the first time and its structure confirmed as xanthotoxin on the basis of melting-point and spectroscopic evidence.

Alkaloids from Crinum delagoense1Part 6 in the series “Alkaloids from South African Amaryllidaceae”. For part 5 see ref.[1].1

Abstract Six alkaloids have been isolated from fresh bulbs of Crinum delagoense . The alkaloids, delagoensine and delagoenine, are reported here for the first time. The structure and stereochemistry of the new alkaloids have been determined by physical and spectroscopic methods. 1 H and 13 C NMR spectra were completely assigned by means of 2D NMR techniques.

Alkaloids from Crinum delagoense1

Abstract Six alkaloids have been isolated from fresh bulbs of Crinum delagoense . The alkaloids, delagoensine and delagoenine, are reported here for the first time. The structure and stereochemistry of the new alkaloids have been determined by physical and spectroscopic methods. 1 H and 13 C NMR spectra were completely assigned by means of 2D NMR techniques.