Three new compounds were isolated from the dried bulbs of Allium macrostemon Bunge. Their structures were elucidated from their spectral data as (25R)-26-O-beta-D-glucopyranosyl-5alpha-furostane-3beta,12beta,22,26-tetraol-3-O-beta-D-glucopyranos-yl (1-->2) [beta-D-glucopyranosyl (1-->3)]-beta-D-glucopyranosyl (1-->4)-beta-D-galactopyranoside (1), (25R)-26-O-beta-D-glucopyranosyl-5alpha-furostan...

The homeobox protein STF-1 appears to function as a master control switch for expression of the pancreatic program during development. Here we characterize a composite enhancer which directs STF-1 expression to pancreatic islet cells via two functional elements that recognize the nuclear factors HNF-3beta and BETA-2. In keeping with their inhibitory effects on islet cell maturation, glucocortic...

KSHV (Kaposi's sarcoma-associated herpesvirus), or HHV-8 (human herpesvirus 8), is associated with the pathogenesis of KS, the most common AIDS-related malignancy. xCT (functional subunit of the cystine/glutamate transporter xc- system) is known as the HHV-8 fusion-entry receptor as well as an oncogenic protein. How the xCT triggers the signal transduction of HHV-8 infection and the cell prolif...

Four mutants strains of Aspergillus fennelliae resistant to various polyene antibiotics have been analyzed for their sterol content. The mutant strains contained Delta(7,22,24(28))-ergostatrien-3beta-o1 and Delta(7,22)-ergostadien-3beta-o1 as the major sterols, whereas the wild types contained ergosterol, indicating that the mutants contain metabolic blocks for C(5)-C(6) dehydrogenation and C(2...

Three new cucurbitane triterpenoids 1-3 and one new steroidal glycoside 4, were isolated together with ten known compounds from Momordica charantia. The structures of new compounds were determined to be 19(R)-n-butanoxy-5 beta,19-epoxycucurbita-6,23-diene-3beta,25-diol 3-O-beta-glucopyranoside (1), 23-O-beta-allopyranosylecucurbita-5,24-dien-7 alpha,3beta,22(R),23(S)-tetraol 3-O-beta-allopyrano...

Human herpesvirus 7 (HHV-7), which belongs to the betaherpesvirus subfamily, infects mainly CD4+ T cells in vitro and infects children during infancy. After the primary infection, HHV-7 becomes latent. HHV-7 contains two genes (U12 and U51) that encode putative homologs of cellular G-protein-coupled receptors. To analyze the biological function of the U12 gene, we cloned the gene and expressed ...

Epithelial Na+ channels (ENaCs) mediate sodium reabsorption in the cortical collecting duct (CCD), but the regulatory pathways that modulate the activity of these channels are incompletely understood. Here, we observed that endothelin-1 (ET-1) attenuates ENaC activity acutely by reducing the channel's open probability and chronically by decreasing the number of channels in the plasma membrane. ...

Five glycyrrhetinic acid (Ib) derivatives have been synthesized to try to improve the antioxidant activity. Their in vitro antioxidant activities were studied using a cytochrome P450/NADPH reductase system from rat liver microsomes. The generation of microsomal free radicals was followed by oxidation of the DCFH-DA probe, while evaluating the capacity to inhibit reactive oxygen species (ROS) fo...

Hyperphosphorylation of tau at multiple sites has been implicated in the formation of neurofibrillary tangles in Alzheimer's disease; however, the relationship between toxicity and phosphorylation of tau has not been clearly elucidated. Putative tau kinases that play a role in such phosphorylation events include the proline-directed kinases glycogen synthase kinase-3beta (GSK-3beta) and cyclin-...

Lithium is widely used to treat bipolar disorder, but its mechanism of action in this disorder is unknown. Several molecular targets of lithium have been identified, but these putative targets have not been shown to be responsible for the behavioral effects of lithium in vivo. A robust model for the effects of chronic lithium on behavior in mice would greatly facilitate the characterization of ...