Biological activities and distribution of plant saponins.

Biological activities of lignans

Simple indole alkaloids and those with a nonrearranged monoterpenoid unit

Flavonoids and their glycosides, including anthocyanins

Lignans neolignans, and related compounds

The n-hexane soluble and the nonsaponifiable lipid fractions of the edible flower extract of chrysanthemum (Chrysanthemum morifolium) were investigated for triterpene diol and triol constituents. These triterpenes occur as the 3-O-fatty acid esters in the n-hexane soluble fraction from which 26 new and 6 known fatty acid esters were isolated and characterized. From the nonsaponifiable lipid fraction, 24 triterpene diols and triols were isolated, of which 3 were new compounds: (24S)-25-methoxycycloartane-3beta,24-diol (11), (24S)-25-methoxycycloartane-3beta,24,28-triol (22), and 22alpha-methoxyfaradiol (23). Faradiol (9) and heliantriol C (19), present in the nonsaponifiable lipid fraction and as the 3-O-palmitoyl esters in the n-hexane soluble fraction, were the most predominant triterpene diol and triol constituents. Fourteen triterpene diols and triols and 9 fatty acid esters were evaluated with respect to their anti-inflammatory activity against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation in mice. All of the triterpenes examined showed marked inhibitory activity, with a 50% inhibitory dose (ID50) of 0.03-1.0 mg/ear, which was more inhibitive than quercetin (ID50 = 1.6 mg/ear), a known inhibitor of TPA-induced inflammation in mice.

Constituents of compositae plants. 2. Triterpene diols, triols, and their 3-O-fatty acid esters from edible chrysanthemum flower extract and their anti-inflammatory effects

Cyclic adenosine monophosphate (AMP) phosphodiesterase inhibitors contained in Forsythia suspensa were identified as lignans, (+)-pinoresinol (Ja) and (+)-pinoresinol-β-D-glucoside (Id), and their structure-activity relationship was investigated. In pinoresinol congeners, the configuration of the two phenyl rings is very important in relation to the activity. When both of the p-hydroxyl groups in matairesinol congeners are substituted by methyl or glucose, the activities are decreased as compared with those of the unsubstituted compounds.

Inhibition of Cyclic AMP Phosphodiesterase by Lignans

Hot aqueous extracts of medicinal plants used in oriental medicine were tested for their inhibitory effect on beef heart phosphodiesterase to detect biologically active compounds present therein. Of 222 samples tested 22 showed reproducible inhibition. cAMP phosphodiesterase inhibitors contained in Anemarrhena asphodeloides were identified as norlignans and their structure activity relationship was investigated; cis-hinokiresinol, the main inhibitor exhibited a prolongation effect on hexobarbital sleeping time in mice.

Inhibitors of Cyclic AMP Phosphodiesterase in Medicinal Plants

Three new triterpenoid saponins, acanthopanaxosides A (1), B (7), and C (13), were isolated from the leaves of Acanthopanax senticosus, together with 12 known saponins. The structures of these new saponins were established as 3-O-beta-D-glucopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-30-nor-olean-12,20(29)-dien-28-oic acid 28-O-alpha-L-rhamnopyranosyl-(1-->4)-6-O-acetyl-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester (1), 3-O-beta-D-glucopyranosyl-(1-->2)-alpha-L-arabinopyranosyl oleanolic acid 28-O-alpha-L-rhamnopyranosyl-(1-->4)-6-O-acetyl-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester (7), and 3-O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-3beta-hydroxyolean-12-ene-28,29-dioic acid (13), on the basis of spectroscopic analysis and chemical degradation. Among the known compounds, sessiloside and tauroside H1 are reported for the first time from A. senticosus. The biological activity of compounds 1-15 was examined against pancreatic lipase. Ciwujianoside C1 (6), tauroside H1 (11), 3-O-alpha-rhamnopyranosyl-(1-->2)-alpha-arabinopyranosyl mesembryanthemoidigenic acid (12), acanthopanaxoside C (13), sessiloside (14), and chiisanoside (15) inhibited pancreatic lipase activity in vitro. In turn, ciwujianosides C2 (3), D2 (5), C4 (8), and C3 (10) and hederasaponin B (9) enhanced this enzyme.

Biologically active triterpenoid saponins from Acanthopanax senticosus

Seven new amide alkaloids, named N-isobutyl-4-hexanoyl-4-hydroxypyrrolidin-1-one (1), (+/-)-erythro-1-(1-oxo-4,5-dihydroxy-2E-decaenyl)piperidine (2), (+/-)-threo-1-(1- oxo-4,5-dihydroxy-2E-decaenyl)piperidine (3), (+/-)-threo-N-isobutyl-4,5-dihydroxy-2E-octaenamide (4), 1-(1,6-dioxo-2E,4E-decadienyl)piperidine (5), 1-[1-oxo-3(3,4-methylenedioxy-5-methoxyphenyl)-2Z-propenyl]piperidine (6), and 1-[1-oxo-5(3,4-methylenedioxyphenyl)-2Z,4E-pentadienyl]pyrrolidine (7), were isolated from the roots of Piper nigrum, together with 32 known amides. Their structures were elucidated on the basis of spectroscopic analysis and chemical evidence.

Tamotsu Nikaido

Papers

Constituents of compositae plants. 2. Triterpene diols, triols, and their 3-O-fatty acid esters from edible chrysanthemum flower extract and their anti-inflammatory effects

Inhibition of Cyclic AMP Phosphodiesterase by Lignans

Inhibitors of Cyclic AMP Phosphodiesterase in Medicinal Plants

Biologically active triterpenoid saponins from Acanthopanax senticosus

New amide alkaloids from the roots of Piper nigrum.