Naphthol AS-E

The Uses of Naphthol AS-E

Naphthol AS-E is mainly used for dyeing cotton, and also for dyeing viscose fiber and silk. It is often used in combination with blue base or blue salt to dye dark blue and navy blue.

Preparation

4-Chlorobenzenamine and 3-Hydroxy-2-naphthoic acid condensation.

General Description

A cell-permeable naphthamide compound that effectively blocks the interaction between the KIX domain of CBP and the KID domain of CREB in HEK293T-based and cell-free Renilla luciferase (RLuc) complementation assays (IC₅₀ = 2.26 and 2.9 M, respectively) by directly binding to CBP′s KIX domain (K_d ~8.6 M using a recombinant KIX). Shown to inhibit CRE- (cAMP response element) dependent transcription activity induced by forskolin in a HEK293T-based RLuc reporter assay (IC₅₀<2.5 M), while exhibiting little effect against the KID-independent CREB-VP16 transcription activity. Also reported to inhibit the enzymatic activity of Firefly luciferase (IC₅₀ ~1 M), but not that of RLuc.

Biological Activity

NaphtholAS-E is a potent, cell-permeable inhibitor of the KIX-KID interaction. NaphtholAS-E directly binds to the KIX domain of CBP (Kd: 8.6μM) and blocks the interaction between the KIX and KID domains (IC50: 2.26μM). NaphtholAS-E can be used in cancer research.

Synthesis

Naphthol AS-E is synthesized with 2,3-acid and p-chloroaniline as raw materials and chlorobenzene as solvent. First, 2,3-acid is made into sodium salt, and then condensed with p-chloroaniline in the presence of PCl3, and the finished product is obtained by neutralization, distillation, filtration and drying.

in vitro

CREB (cyclic AMP-response element-binding protein) is a downstream transcription factor of a multitude of signaling pathways emanating from receptor tyrosine kinases or G-protein coupled receptors.CREB can not be activated until it is phosphorylated at Ser133 and its subsequent binding to CREB-binding protein (CBP) through the kinase-inducible domain (KID) in CREB and KID-interacting (KIX) domain in CBP.In a cell-based CREB Renilla luciferase reporter assay, Naphthol AS-E inhibits CREB-mediated gene transcription with an IC 50 of 2.29 μM. In HEK293T-based complementation assay, Naphthol AS-E dose-dependently inhibited Renilla luciferase activity with an IC 50 of 2.9 μM by directly binding to CBP's KIX domain (K d ~8.6 μM using a recombinant KIX).Naphthol AS-E exhibits low μM activity in inhibiting the proliferation of all these cancer cells, which is consistent with its cellular CREB inhibition potency. The average GI 50 values for A549, MCF-7, MDA-MB-231 and MDA-MB-468 are approximately 2.9μM, 2.81μM, 2.35μM and 1.46μM, respectively.Naphthol AS-E (2.5 μM-10 μM; 48 hours) decreases the expression of anti-apoptotic protein Bcl-2. The expression of VEGF is also decreased.

Properties and Applications

light yellow microstrip red uniform powder, melting point for 258 ~ 259 ℃. Insoluble in water solution and sodium carbonate, soluble in adjacent two chlorobenzene, ethanol and glacial acetic acid. Sodium hydroxide solution for yellow in the liquid. Sensitive to air. Mainly used for cotton fabrics, viscose and silk dyeing, general is not used for printing, and can be used as organic pigments intermediate. This product to cotton affinity is higher, coupled ability medium.