Two new sesquiterpene lactones, 1, 4-epoxy-6-deoxypseudoanisatin and neodunnianin, were isolated from the pericarp of Illicium dunnianum, together with a sesquiterpene, phaseic acid. Their structures were elucidated on the basis of spectroscopic and chemical data. The structure of neodunnianin was confirmed by X-ray diffraction analysis.

Four seco-prezizaane sesquiterpene lactones, 14-O-n-butyrylfloridanolide, 3, 4-dehydro-oridanolide, 3, 6-dideoxy-10-hydroxy-pseudoanisatin, and 2-O-n-butyrylpseudomajucin were isolated from the pericarps of Illicium merrillianum. Their structures were determined by spectroscopic methods.

Two new anislactone-type sesquiterpenes, merrilactones B (1) and C (2) were isolated from the pericarps of Illicium merrillianum along with anislactones A (4) and B (5). Their structures were elucidated by spectroscopic methods and chemical transformation and the structure of merrilactone C was established by X-ray crystallographic analysis of its methyl derivative. Merrilactone A (3), a unique anislactone-type sesquiterpene showing neurite outgrowth promoting activity, was effectively synthesized from anislactone B.

八角科植物70%的种分布于我国西南部至东部，仅八角茴香Illicium uerum的果实和地枫皮I. difengpi树皮被《中国药典》1995年版收载，其它多为民间用药。因八角科植物果实形态多相似，含较强毒性成分，为保证用药安全，本文描述了16种八角果实形态特征，并列有检索表，为八角科植物果实鉴别提供依据。

An extract of the pericarps of Illicium merrillianum has yielded four new sesquiterpenes: 3Rhydroxycycloparvifloralone (1), 1, 2-dehydrocycloparvifloralone (2), (11) 7, 14-ortholactone-3R-hydroxyfloridanolide (3), and 11-O-debenzoyltashironin (4) along with cycloparvifloralone (5), merrillianone (6), and tashironin (7). The structures of 1-4 were determined on the basis of spectroscopic analyses. 11-O-Debenzoyltashironin (4) showed neurotrophic activity in primary culture of rat cortical neurons at 0.1-10μM. However, cycloparvifloralone-type sesquiterpenes (1, 2, 5, and 6) and tashironin (7) had no neurotrophic activity at these concentrations.

Seven new seco-prezizaane-type sesquiterpenes were isolated from the methanol extract of the pericarps of Illicium merrillianum. Their structures were elucidated as 3-deoxypseudoanisatin (1), 2 β-hydroxy-3, 6-dedioxypseudoanisatin (2), 8 α-hydroxy-10-deoxycyclomerrillianolide (3), 10 β-hydroxypseudoanisatin (4), 10 β-hydroxycyclopseudoanisatin (5), 1, 6-dihydroxy-3-deoxyminwanensin (6), and 8-deoxymerrilliortholactone (7) by analyses of their spectroscopic data and chemical transformation. Compounds 4 and 5 as well as 6 and 7 coexist as a keto/acetal equilibrated mixture in methanol solution.

In the study of bioactive substances in Illicium plants, the methanol extract of I. merrillianum showed brine shrimp lethality test (BST) activity at 200μg/ml. Bioassay-guided fractionation of the BST active fractions resulted in the isolation of 4-O-methyleudesm-11-en-4α-ol, eudesmol-11-en-4α-ol and (-)-hinokinin as potent BST active compounds. On the other hand, four new highly oxygenated seco-prezizaane-type sesquiterpenes, merrilliortholactone (1), 2 α-hydroxycycloparvifloralone (2), 2 α-hydroxycycloparviflorolide (3), and 2 α-hydroxyanisatin (4) were isolated from the BST-inactive polar fractions. The structures of new compounds were elucidated by extensive analyses of spectral data. Furthermore, the absolute configuration of 3 was established by the modified Mosher's method. Compounds 1-4 showed neither BST activity at 100mg/ml nor neurite outgrowth-promoting activity.

Novel sesquiterpene lactones, (6R)-pseudomajucin (1) and merrillianin (3), have been isolated from the pericarps of Illicium merrillianum, and their structures have been elucidated on the basis of the spectral data. A methanol solution of (6R)-pseudomajucin coexisted with (6R)-pseudomajucinone (2) in a keto/acetal equilibrium, whereas the crystals solely consisted of a keto-type 2, the structure of which was established by X-ray crystallographic analysis. The absolute stereochemistry of 1 was determined by the X-ray crystallographic analysis of its 7-O-methyl-3-O-p-bromophenylcarbamate. Merrillianin (3) is a unique seco-prezizaane-type sesquiterpene with an unprecedented dilactone moiety, which may be biosynthesized from pseudomajucin (4) or (6R)-pseudomajucin (1) by oxidative cleavage of the C-6/C-7 bond.

Merrilactone A, isolated from the pericarps of Illicium merrillianum, shows an intriguing neurotrophic activity in the cultures of fetal rat cortical neurons. Its structure has been elucidated to be a unique ses-quiterpene bearing two γ-lactones and an oxetane ring by extensive analyses of spectral data and then confirmed by X-ray crystallographic analysis. Further, the absolute configuration has been established by the modified Mosher's method.

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), 1Rhydroxy-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.