alpha-Lapachone, a natural product isolated and purified from the barks of Catalpa ovata, does not induce H₂O₂ formmation but shows an approximately the same trypanocidal activity of beta-lapachone.

9-Hydroxy-alpha-lapachone, a natural product isolated and purified from the herbs of Catalpa ovata, exhibits potent inhibitory activity against H. pylori Cystathionine gamma-synthase, with IC(50) values of 4.64 mM.

6-O-Feruloylglucose is a natural product isolated and purified from the herbs of Catalpa fargesii f. duclouxii.

1-Hydroxy-2-prenylnaphthalene is a natural product isolated and purified from the herbs of Catalpa ovata.

Deoxylapachol induced fungal cell wall stress and inhibited fungal growth.