The revised structure of pseudoanisatin by X-ray crystal structure determination

Illicium verum: a review on its botany, traditional use, chemistry and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

The fruit of Illicium verum Hook. f. (Chinese star anise) has long been used in traditional Chinese medicine and food industry with the actions of dispelling cold, regulating the flow of Qi and relieving pain.

MATERIALS AND METHODS

A bibliographic investigation was carried out by analyzing recognized books including Chinese herbal classic, and worldwide accepted scientific databases (Pubmed, SciFinder, Scopus and Web of Science) were searched for the available information on I. verum.

RESULTS

I. verum is an aromatic evergreen tree of the family Illiciaceae. It is sometimes contaminated with highly toxic Japanese star anise (I. anisatum L.) and poisonous star anise (I. lanceolatum A. C. Smith), which contain several neurotoxic sesquiterpenes. Traditional uses of I. verum are recorded throughout Asia and Northern America, where it has been used for more than 10 types of disorders. Numerous compounds including volatiles, seco-prezizaane-type sesquiterpenes, phenylpropanoids, lignans, flavonoids and other constituents have been identified from I. verum. Modern pharmacology studies demonstrated that its crude extracts and active compounds possess wide pharmacological actions, especially in antimicrobial, antioxidant, insecticidal, analgesic, sedative and convulsive activities. In addition, it is the major source of shikimic acid, a primary ingredient in the antiflu drug (Tamiflu).

AIM OF THE REVIEW

This review summarizes the up-to-date and comprehensive information concerning the botany, traditional use, phytochemistry and pharmacology of I. verum together with the toxicology, and discusses the possible trend and scope for future research of I. verum.

Seco-prezizaane-type sesquiterpenes and an abietane-type diterpene from Illicium minwanense

A methanol extract of the pericarps of Illicium minwanense afforded seven new seco-prezizaane-type sesquiterpenes (2-8) and a new abietane-type diterpene (9), together with six previously known compounds (1 and 10-14). The structures of the new compounds, (1S)- and (1R)-minwanenone (2 and 3), 1alpha-hydroxy-6-deoxypseudoanisatin (4), (2S)-hydroxy-6-deoxypseudoanisatin (5), 3-oxopseudoanisatin (6), (3S,6R)-4,7-epoxy-6-deoxypseudoanisatin (7), 7-O-methylpseudomajucin (8), and (+)-8,11,13,15-abietatetraene (9), were elucidated by spectroscopic data analysis and chemical transformations. The absolute configurations of 1 and 5 were established by X-ray crystallographic analysis of their p-bromobenzoyl derivatives.

New seco-prezizaane-type sesquiterpenes, jiadifenin with neurotrophic activity and 1,2-dehydroneomajucin from Illicium jiadifengpi

Two new seco-prezizaane-type sesquiterpenes, 1,2-dehydroneomajucin (1) and jiadifenin (2), were isolated from the methanol extract of the pericarps of Illicium jiadifengpi, indigenous to the southern part of China. Their structures were elucidated on the basis of NMR data. Compound 2, which is an equilibrated mixture of the epimers 2a and 2b on the C-10 acetal carbon, is the first example of a majucin-type seco-prezizaane with an oxo-function at the C-10 position. The proposed structure for 2 was unambiguously confirmed by chemical conversion of the known sesquiterpene (2S)-hydroxy-3,4-dehydroneomajucin (5) to 2. Compounds 2 and 5 were found to significantly promote neurite outgrowth in primary cultures of fetal rat cortical neurons at concentrations from 0.1 to 10 microM.

A prezizaane sesquiterpene from Illicium angustisepalum

The prezizaane sesquiterpene angustisepalin has been isolated from the aerial parts of Illicium angustisepalum, and its structure determined by 2D-NMR spectroscopy. Angustisepalin is formally the 10-benzoyl ester of neomajucin, previously reported from Illicium majus.