Xestospongin C is a marine natural product which was first isolated from Pacific basin sponges, and noted to have vasodilatory properties.{9844} Xestospongin C antagonizes the calcium-releasing action of inositol-1,4,5-trisphosphate (IP3) at the receptor level. Inositol phosphates are important signal transduction messengers acting via IP3 receptors to promote the mobilization of Ca2+ from intracellular stores. Xestospongin C blocks the increase in intracellular calcium in vascular smooth muscle cells completely at a concentration of 25 µM.{9845} Xestospongin C also inhibits the sarcoplasmic reticulum Ca2+ ATPase pump at concentrations of 700 nM.{10509}
Available on backorder
An inositol-1,4,5-trisphosphate receptor antagonist; completely blocks the increase in intracellular calcium in vascular smooth muscle cells at a concentration of 25 µM
Formal name: [1R-(1R,4aR,11R,12aS,13S,16aS,23R,24aS)]-eicosahydro-5H,17H-1,23:11,13-diethano-2H,14H-[1,11]dioxacycloeicosino[2,3-b:12,13-b1]dipyridine
Synonyms: Araguspongine E|XeC
Molecular weight: 446.7
CAS: 88903-69-9
Purity: ≥90%
Formulation: A clear film
The maintenance of embryonic stem cells in culture typically requires feeder cells and various exogenous factors found in serum. Murine embryonic stem (mES) cells can be maintained in the absence of feeder cells and serum but require the leukemia inhibitor factor (LIF) and bone morphogenic protein (BMP) to prevent differentiation and promote self-renewal. SC-1 is a small molecule activator of stem cell renewal that allows the propagation of OG2 mES cells for at least 10 passages in an undifferentiated state.{14533} The activity of SC-1 is mediated by the combined inhibition of RasGAP and ERK1 with Kd values of 98 and 212 nM, respectively.{14533} Inhibition of RasGAP increases Ras signaling via the PI3-kinase pathway which promotes self-renewal, whereas inhibition of ERK blocks differentiation.
Available on backorder
The nuclear factor-κB (NF-κB) regulates the expression of numerous genes involved in immunity and inflammation, cellular stress responses, growth, and apoptosis. Resveratrol, a polyphenolic trans-stilbene, is a known inhibitor of the activation of NF-κB and exhibits activity against a wide variety of cancer cells. CAY10512 is a substituted trans-stilbene analog of resveratrol that is 100-fold more potent as measured by antioxidant activity. The IC50 value for inhibition of TNFα-induced activation of NF-κB by CAY10512 is 0.15 µM compared to 20 µM by resveratrol.{14545}
Available on backorder
Cyclin-dependent kinases (CDKs) are key regulators of cell cycle progression and are therefore promising targets for cancer therapy. (R)-Roscovitine is a potent inhibitor of Cdk2/cyclin E with an IC50 value of 0.1 µM.{14988} It also inhibits Cdk7/cyclin H, Cdk5/p35, and cell division cycle (cdc)/cyclin B with IC50 values of 0.49, 0.16, and 0.65 µM, respectively.{14987,14988,14991} (R)-Roscovitine inhibits the growth of rapidly proliferating cells with an average IC50 value of 15.2 µM against a panel of 19 human tumor cell lines.{14988} In murine models of polycystic kidney disease, (R)-roscovitine effectively inhibited disease progression at doses of 50-100 mg/kg.{14564}
Available on backorder
The tetracycline repressor (TetR) is a transcriptional regulator which normally binds tightly to its palindromic tetO operator DNA, blocking gene expression.{17508} Tet causes the repressor to dissociate from the DNA, allowing transcription to occur. A novel reverse TetR (revTetR) requires tetracycline as a co-repressor to bind tetO and block transcription.{17509,17510} Anhydrotetracycline (hydrochloride) is a powerful effector in both the tetracycline repressor (TetR) and reverse TetR (revTetR) systems, binding the Tet repressor 35-fold more strongly than Tet.{17508,17511} Moreover, anhydrotetracycline poorly binds the 30S ribosomal subunit, compared to Tet,{17512} so it does not act as a general inhibitor of translation and is a poor antibiotic. Perhaps related to this, the concentration of anhydrotetracycline that inhibits eukaryotic cell growth is more than a 1,000-fold above the dose that alters transcription through TetR.{17508}
Available on backorder