[Studies on chemical constituents in the mycelia from fermented culture of Flammulina velutipes].

OBJECTIVE: To study the chemical constituents from the mycelia of Flammulina velutipes. METHOD: The compounds were isolated with silica gel column chromatography and their structures were elucidated on the basis of chemical evidences and spectral analysis (IR, EI-MS, 1H-NMR, 13C-NMR). RESULT: Five compounds were identified as 5alpha,8alpha-epidioxy-(22E,24R)-ergost-6,22-dien-3beta-ol (1), ergosta-4,6,8(14),22-tetraen-3-one (2), sterpuric acid (3), mannitol (4), ribitol (5). CONCLUSION: The compounds (2)-(5) were isolated for the first time from the mycelia of Flammulina velutipes.

Molecular recognition of carbohydrates by a resorcinarene. Selective transport of alditols through a supported liquid membrane.

A supported liquid membrane (SLM) containing a resorcinarene carrier has been used for the selective transport of erythritol, threitol, ribitol and xylitol from concentrated (1.0-0.01 M) aqueous solutions. The membrane is made of a microporous polytetrafluoroethylene film impregnated with a 0.01 M solution of the carrier in CCl4. The permeabilities of the SLM for all alditols were calculated. On the basis of the flux dependence on the initial concentrations of carrier and alditol, the rate-determining step in the transport mechanism is shown to be the migration of the 1:1 carrier-carbohydrate complex in the immobilized organic phase. The flux of sugar is related to the initial concentration of alditol in the feed phase by a saturation law, which allowed the determination of the apparent diffusion coefficients and the stability constants of the resorcinarene complexes of alditols formed in the liquid membrane.

Authentic standards for the reductive-cleavage method. The positional isomers of partially methylated and acetylated or benzoylated 1,5-anhydroribitol.

The eight positional isomers of methylated and benzoylated 1,5-anhydroribitol were generated simultaneously from 1,5-anhydroribitol by sequential partial methylation and benzoylation, and the four meso isomers and two enantiomeric pairs of isomers so-formed were isolated in chemically pure form by high-performance liquid chromatography. The corresponding acetates were obtained by debenzoylation of the pure isomers and acetylation. Reported herein are the 1H NMR spectra of the benzoates and the electron-ionization mass spectra of the acetates and the tri-O-methyl derivative. Also reported for the acetates and the tri-O-methyl derivative are their linear temperature-programmed gas-liquid chromatography retention indices on three different capillary columns.

Kelletinin A, from the marine mollusc Buccinulum corneum, promotes differentiation in Hydra vulgaris.

The effects of kelletinin A [ribityl pentakis (p-hydroxybenzoate)] (KA), a natural compound isolated from the marine gastropod Buccinulum corneum, were studied in vivo in Hydra vulgaris during regeneration. KA caused a marked increase of regenerated tentacle numbers (ATN) and promoted transdifferentiation of epithelial cells into battery cells, and nematocyte differentiation. Morphological data were correlated to changes in acid and alkaline phosphatase levels, enzymes that have been described as regeneration markers.

Kelletinin I and kelletinin A from the marine mollusc Buccinulum corneum are inhibitors of eukaryotic DNA polymerase alpha.

The inhibitory effect of esters of p-hydroxybenzoic acid (kelletinins I and A), extracted from the marine gastropod Buccinulum corneum, have been tested on eukaryotic and prokaryotic enzymes of DNA metabolism such as DNA polymerases alpha and beta, DNA polymerase I, Exo III, pancreatic DNAse I, micrococcal DNAse and E. coli RNA polymerase. Kelletinin I and kelletinin A inhibit preferentially DNA polymerase alpha. The inhibitory effect of kelletinin I involves the hydroxyl group of p-hydroxybenzoic acid.