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Radix Inulae is used as a gastric and antibacterial agent in traditional Chinese and Tibetan medicines. Most of its chemical constituents have been identified and include a series of sesquiterpenes with various carbon skeletons such as: eudesmanolide, elemanolide, germacranolide, sesquicaranolide, guaianolide and humulane. Certain organic solvent fractions and sesquiterpenes from Radix Inulae have been found to significantly inhibit the growth of tumor cell strains in vitro. They also show antibacterial, cardiovascular and hypoglycaemic as well as insulin-sensitization activities. The present review summarizes research on the chemistry and biological activity of Radix Inulae.

Four rare isoryanodane diterpenoids namely itols A–D (1–4) and two isoryanodane glucosides (5 and 6) were isolated from the bark and twigs of Itoa orientalis. Their structures were determined by NMR and MS techniques and the structure of 1 was confirmed by a single-crystal X-ray diffraction. These six diterpenoids obviously showed insecticidal activity against Spodoptera exigua, with LC50 28.62 ppm for 1 and 52.76 ppm for 2, respectively. In anti-inflammatory assay, compounds 1 and 4–6 showed anti-COX-2 activity, with inhibitory rates of 54.7–78.3% at 10 μM.

Two new phenolic glycosides, scolochinenosides A and B (1 and 2), and a new flavonoid glycoside, scoloside A (3), were isolated from the leaves of Scolopia chinensis (Lour.) Clos, together with eight known compounds. The structures of the new compounds were established on the basis of chemical and spectroscopic evidences.

Three new glycosides with the same saccharides, namely miliusoside A (1), miliusoside B (2), and miliusoside C (3), together with five known compounds were isolated from the stems of Miliusa balansae. Their structures were elucidated on the basis of detailed spectroscopic analysis and by comparison with the spectra of related model compounds. There was a rarely encountered α-D-apiose moiety occurring in all new compounds.

Eight new benzoylated gentisyl alcohol (=2-(hydroxymethyl)benzene-1,4-diol) glucosides, itosides A–H (1–8), together with the new pyrocatechol (=benzene-1,2-diol) glycoside itoside I (9) were isolated from the bark and twigs of Itoa orientalis (Flacourtiaceae). In itosides B–D (2–4), the gentisyl alcohol moiety was esterified by 1-hydroxy-6-oxocyclohex-2-ene-1-carboxylic acid, while itosides E–H (5–8) contained instead an additional 2-hydroxybenzoic acid moiety. The compounds were accompanied by the known derivatives 4-hydroxytremulacin (10), poliothyrsoside (11), poliothyrsin (12), homaloside D (13), tremulacin, and pyrocatechol β-D-glucopyranoside. The structures of the new compounds were elucidated by spectral and chemical methods.