Etoposide EP Impurity O is a related impurity of etoposide formed during the hydrolysis ring-opening of the 4,6-O-ethylidene protecting group in the sugar ring or during chemical synthesis. It is one of the specified impurities for the quality control of etoposide drug substances and formulations as defined by the European Pharmacopoeia (EP).

4,6-O-(1R)-Ethylidene-β-D-glucopyranose(Ethylidene glucose), a glucose derivative, is a competitive exofacial binding-site inhibitor on glucose transporter 1 (GLUT1).

β-D-Glucopyranose, 4,6-O-(1R)-ethylidene-, 2,3-bis(2,2-dichloroacetate) is a derivative formed by esterification of the 2,3-hydroxyl groups of 4,6-O-ethylidene-α-D-glucose with dichloroacetic acid. It is a key intermediate for glycosyl donor activation in etoposide synthesis and serves as a precursor to etoposide EP Impurity O.

β-D-Glucopyranose, 4,6-O-ethylidene-, 2,3-bis(chloroacetate), (R) is a derivative formed by esterification of the 2,3-hydroxyl groups of 4,6-O-ethylidene-α-D-glucose with chloroacetic acid. It is a key intermediate for glycosylation activation in etoposide synthesis and is commonly used in the glycosyl donor activation step in the industrial production of etoposide.

1,8-Cineole is an inhibitor of 5-HT3 receptor,potassium channel, TNF-α and IL-1β.

2''-O-Galloylhyperin upregulates SIRT1/Nrf2 signaling, inhibits NF-κB and MAPK (ERK1/2, p38, JNK) phosphorylation, suppresses TSHR activation, reduces ROS accumulation, and enhances SOD and GSH-Px activities.

4'-O-beta-Glucopyranosyl-5-O-methylvisamminol is an active natural chromone glycoside with multiple biological activities.

6-Gingerol is an active compound isolated from Ginger (Zingiber officinale),.

8-Gingerol can be found in the rhizome of ginger (Z. officinale).

10-Gingerol is an AMPK agonist, which is found in the ginger oleoresin from fresh rhizome.

6-Shogaol is the derivative of Shogaol (HY-14616) found in Ginger (Zingiber officinale Rosc).

8-Shogaol is an effective apoptosis inducer and growth inhibitor.

10-Shogaol is a 5-HT1A receptor partial agonist found in Zingiber officinale.

(-)-Epigallocatechin is the most abundant flavonoid in green tea, can bind to unfolded native polypeptides and prevent conversion to amyloid fibrils.

(-)-Gallocatechin Gallate (GCG) is the polyphenol isolated from tea,.

4-(Bromomethyl)-7-methoxycoumarin is often used as fluorescent label for the determination of compounds possessing a carboxylic group.