Hydroxysafflor yellow A is a natural product of flavonoids isolated from safflower.

Hyperoside is a NF-κB inhibitor, found from Hypericum monogynum.

Hypaconitine acts as the neuromuscular blocker.

Icariin is a flavonol glycoside. Icariin inhibits PDE5 and PDE4 activities and it is also a PPARα activator.

Imperatorin is an effective of NO synthesis inhibitor, which also is a BChE inhibitor and a weak agonist of TRPV1.

Indirubin is a bis-indole alkaloid.

Isoferulic acid is a cinnamic acid derivative.

Isofraxidin, a coumarin component from Acanthopanax senticosus, inhibits MMP-7 expression.

Isoliquiritin, isolated from Licorice Root, inhibits angiogenesis and tube formation.

Isoliquiritigenin is a flavonoid from the root of Glycyrrhiza uralensis Fisch., which inhibits aldose reductase. Isoliquiritigenin is a potent inhibitor of influenza virus replication.

Isoimperatorin is a methanolic extract of the roots of Angelica dahurica shows significant inhibitory effects on acetylcholinesterase (AChE) .

Isoorientin (Homoorientin) is a potent inhibitor of COX-2.

Isopimpinellin, an compound isolated from Glomerella cingulata.

Isopsoralen is a furanocoumarin compound that functions as an inhibitor of NF-κB and MAPK signaling pathways.

Isorhynchophylline is an alkaloid isolated from Crocus sativus.

Isovitexin is a flavonoid isolated from passion flower and the palm, etc.