Search results for "Steroid"
showing 10 items of 1005 documents
Mechanisms of ceramide-induced COX-2-dependent apoptosis in human ovarian cancer OVCAR-3 cells partially overlapped with resveratrol.
2013
Ceramide is a member of the sphingolipid family of bioactive molecules demonstrated to have profound, diverse biological activities. Ceramide is a potential chemotherapeutic agent via the induction of apoptosis. Exposure to ceramide activates extracellular-signal-regulated kinases (ERK)1/2- and p38 kinase-dependent apoptosis in human ovarian cancer OVCAR-3 cells, concomitant with an increase in the expression of COX-2 and p53 phosphorylation. Blockade of cyclooxygenase-2 (COX-2) activity by siRNA or NS398 correspondingly inhibited ceramide-induced p53 Ser-15 phosphorylation and apoptosis; thus COX-2 appears at the apex of the p38 kinase-mediated signaling cascade induced by ceramide. Induct…
Synthesis and anti-inflammatory activity of chalcone derivatives
1998
Chalcones and their derivatives were synthesized and evaluated for their anti-inflammatory activity. In vitro, chalcones 2, 4, 8, 10 and 13 inhibited degranulation and 5-lipoxygenase in human neutrophils, whereas 11 behaved as scavenger of superoxide. Only four compounds (4-7) inhibited cyclo-oxygenase-2 activity. The majority of these samples showed anti-inflammatory effects in the mouse air pouch model.
High-performance and ion-exchange chromatography and chromatofocusing of the human uterine progesterone receptor: its application to the identificati…
1984
Two independent lines of evidence were used to identify the human uterine progesterone receptor. First, three differently tritiated progestogens (Org 2058, R 5020, progesterone) were used for reversible labelling of the receptor. Secondly, the highly potent affinity label 21-[3H]dehydro Org 2058 was used to label covalently the steroid-specific binding site of the receptor. The labelled cytosols were chromatographed on a Mono Q high-performance anion-exchange column in the absence or presence of a high molar excess of the respective unlabelled competitor steroids. In the case of 21-[3H]dehydro Org 2058, Org 2058 was used as the unlabelled competitor. After elution with a NaCl gradient, the …
Cytotoxic Spirostane-Type Saponins from the Roots of Chlorophytum borivilianum
2009
Four new spirostane-type saponins named borivilianosides E-H (1-4) were isolated from an ethanol extract of the roots of Chlorophytum borivilianum together with two known steroid saponins (5 and 6). The structures of 1-4 were elucidated using mainly 2D NMR spectroscopic techniques and mass spectrometry. The cytotoxicity of borivilianosides F (2), G (3), and H (4) and three known compounds was evaluated using two human colon cancer cell lines (HT-29 and HCT 116).
Clean method for the simultaneous determination of propyphenazone and caffeine in pharmaceuticals by flow injection Fourier transform infrared spectr…
1997
A procedure is proposed for the simultaneous FTIR determination of propyphenazone (PFZ) and caffeine (CAF) in pharmaceuticals. The method involves the dissolution of the active principles in CHCl 3 , followed by filtration of sample solutions to remove the excipients. PFZ is then determined by absorbance measurements at 1595 cm - 1 , using a baseline established between 2000 and 890 cm - 1 , and CAF by using the first-derivative values at 1712 cm - 1 , using solutions of PFZ and CAF for external calibration. The method was applied in both the stopped-flow and flow-injection modes, providing precise and accurate results for the analysis of real samples. The incorporation of a distillation un…
Sterols and Steroids
1994
Sterols and steroids, like the terpenes and carotinoids, are isoprene derivatives. The sterols are components of the membranes of all eukaryotic cells and they bind and condense the phospholipid bilayer. The outer cell membrane is particularly rich in sterols, with a molar ratio of sterols to phospholipids of 0.8–0.1, compared with the usual value of 0.1–0.3 for intracellular membranes. The parent substance of all sterols is cholesterol (Fig. 16.1). The sterols are classified with the steroid hormones and bile salts as steroids because they also have the gonan (formerly steran) four-ring system and have their biosynthetic origin in cholesterol. Steroids with hormonal functions are known fro…
Antioxidative succinobucol–sterol conjugates: Crystal structures and pseudosymmetry in the crystals
2012
Abstract An extensive study to attach succinobucol to sterols has provided conjugates which comprise two pharmaceutically important compounds into one entity where the components are expected to have a synergistic effect. The motivation to design these novel conjugates was the need to broaden the armamentarium of current agents used in the treatment of atherosclerotic diseases and type 2 diabetes. In desire for detailed information of these compounds in solid state, which also have an influence to their physiological activity, systematic crystallization experiments were performed and as a result, X-ray quality single crystals were obtained from four succinobucol–sterol conjugates. All of th…
Organoelement derivatives of steroids: synthesis and structural characterization of diorganotin chloride adducts of hormones
1986
Abstract Ten new diorganotin dichloride adducts of hormones of the type R 2 SnCl 2 ·2L [where R = Me, Et, n-Bu, Oct and Ph; L = 4-androsten-17s-ol-3-one ( A ); 5-androsten-3s-ol-17-one ( B ); 4-androsten-17α- methyl-17s-ol-3-one ( C ) and 3,17-dihydroxy-5- pregnene-20-one ( D )] have been prepared and characterized at 297 K and 223 K. Spectroscopic measurements (IR; Raman; 1 H, 13 C, 119 Sn NMR) suggest the dissociation or fast ligand exchange in solution at 297 K. Hexa-coordinated adducts with bonding through carbonyl oxygen and trans -R groups in octahedral geometry are formulated at 223 K.
ChemInform Abstract: Asymmetric Allylation/Pauson-Khand Reaction: A Simple Entry to Polycyclic Amines. Application to the Synthesis of Aminosteroid A…
2014
Asymmetric allylation of o-iodoarylsulfinylimines has been achieved in high diastereoselectivities. The thus-obtained o-iodoarylhomoallylic sulfinamides participate in a subsequent Sonogashira coupling followed by a diastereoselective intramolecular Pauson–Khand reaction. In this way, tricyclic amines showing a unique benzo-fused indenyl backbone were obtained. The methodology has been applied to the synthesis of amino steroid analogues.
Anti-inflammatory drimane sesquiterpene lactones from an Aspergillus species
2014
Abstract IFN-γ inducible protein 10 (IP-10, CXCL10) is a 10 kDa chemokine, which is secreted from various cell types after exposure to pro-inflammatory stimuli. This chemokine is a ligand for the CXCR3 receptor and regulates immune responses by activating and recruiting leukocytes such as T cells, eosinophils, monocytes, and NK cells to sites of inflammation. Altered expression of CXCL10 has been associated with chronic inflammatory and infectious diseases and therefore CXCL10 represents a promising target for the development of new anti-inflammatory drugs. In a search for inhibitors of CXCL10 promoter activity, three structurally related drimane sesquiterpene lactones (compounds 1–3) were …