Biomedical subjects

Robert E Raulli

Publications and source records attributed to Robert E Raulli.

3 recordsLinked to original sources

PubMed2003

Flavanone glycosides from Miconia trailii.

Assay-guided fractionation of the ethanol extract of the twigs and leaves of Miconia trailii yielded two new flavanone glycosides, matteucinol 7-O-alpha-l-arabinopyranosyl(1-->6)-beta-d-glucopyranoside (miconioside A, 1) and farrerol 7-O-beta-d-apiofuranosyl(1-->6)-beta-d-glucopyranoside (miconioside B, 2), along with the known compounds matteucinol 7-O-beta-d-apiofuranosyl(1-->6)-beta-d-glucopyranoside (3), matteucinol (4), 2alpha,3beta,19alpha-trihydroxyolean-12-ene-24,28-dioic acid (bartogenic acid, 5), 2alpha,3beta,23-trihydroxyolean-12-ene-28-oic acid (arjunolic acid, 6), 2alpha,3alpha,19alpha, 23-tetrahydroxyurs-12-ene-28-oic acid (myrianthic acid, 7), and stigmast-4-ene-3,6-dione (8). The structures of 1-8 were elucidated by spectroscopic methods, including 2D NMR.

Cholestenones↗

PubMed2003

Phenolic compounds from Nymphaea odorata.

Assay-guided fractionation of the ethanol extract of Nymphaea odorata resulted in the identification of two lignans, one new (1) and one known (2), together with six known flavonol glycosides (3-8). The structures of 1-8 were established by spectroscopic analysis as nymphaeoside A (1), icariside E(4) (2), kaempferol 3-O-alpha-l-rhamnopyranoside (afzelin, 3), quercetin 3-O-alpha-l-rhamnopyranoside (4), myricetin 3-O-alpha-l-rhamnopyranoside (myricitrin, 5), quercetin 3-O-(6' '-O-acetyl)-beta-d-galactopyranoside (6), myricetin 3-O-beta-d-galactopyranoside (7), and myricetin 3-O-(6' '-O-acetyl)-beta-d-galactopyranoside (8). Compounds 3, 4, and 7 showed marginal inhibitory effect against fatty acid synthase with IC(50) values of 45, 50, and 25 microg/mL, respectively.

Enzyme Inhibitors↗

PubMed2002

Fatty acid synthase inhibitors from plants: isolation, structure elucidation, and SAR studies.

Fatty acid synthase (FAS) has been identified as a potential antifungal target. FAS prepared from Saccharomyces cerevisiae was employed for bioactivity-guided fractionation of Chlorophora tinctoria,Paspalum conjugatum, Symphonia globulifera, Buchenavia parviflora, and Miconia pilgeriana. Thirteen compounds (1-13), including three new natural products (1, 4, 12), were isolated and their structures identified by spectroscopic interpretation. They represented five chemotypes, namely, isoflavones, flavones, biflavonoids, hydrolyzable tannin-related derivatives, and triterpenoids. 3'-Formylgenistein (1) and ellagic acid 4-O-alpha-l-rhamnopyranoside (9) were the most potent compounds against FAS, with IC(50) values of 2.3 and 7.5 microg/mL, respectively. Furthermore, 43 (14-56) analogues of the five chemotypes from our natural product repository and commercial sources were tested for their FAS inhibitory activity. Structure-activity relationships for some chemotypes were investigated. All these compounds were further evaluated for antifungal activity against Candida albicans and Cryptococcus neoformans. Although there were several antifungal compounds in the set, correlation between the FAS inhibitory activity and antifungal activity could not be defined.

Antifungal Agents↗