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A new triterpenoid saponin was isolated from the roots of Silene cucubalus and its structure was determined on the basis of one- and two-dimensional NMR spectroscopy as gypsogenin 3-O-beta-xylopyranosyl-(1-->3)-[beta-galactopyranosyl-(1-->2)]-beta-glucuronopyranoside. A known saponin, quillaic acid 3-O-beta-xylopyranosyl-(1-->3)-[beta-galactopyranosyl-(1-->2)]-beta-glucuronopyranoside, was also isolated.

Two minor saponins obtained from the methanolic extract of the leaves of Ilex paraguariensis have been characterised by 13C-NMR, 1H-NMR, API-MS and chemical hydrolysis as oleanolic acid-3-O-(beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl)-(28-->1)- beta-D-glucopyranosyl ester (guaiacin B) and oleanolic acid-3-O-(beta-D-glucopyranosyl-(1-->3)-(alpha-L-rhamnopyranosyl- (1-->2))-alpha-L-arabinopyranosyl)-(28-->1)-beta-D-glucopyranosyl ester (nudicaucin C). Both are isomeric forms of the known matesaponins 1 (MSP 1) and 2 (MSP 2) and differ only by the nature of the aglycone: they have oleanolic acid instead of ursolic acid, as found in the matesaponins. These minor saponins have not been fully separated from their major isomers MSP 1 and 2 and were characterised by in-mixture NMR analysis, LC-MS and LC-MSn experiments.

Five monodesmosidic serjanic acid saponins and a monodesmosidic spergulagenic acid saponin were isolated from an aqueous extract of the berries of Phytolacca icosandra. A methanol extract of the berries furnished three bidesmosidic serjanic acid glycosides. Their structures were established by spectroscopic (ES-MS, 1H NMR, COSY, HSQC, HMBC, 13C NMR) and chemical methods. The molluscicidal, spermicidal and haemolytic properties of the saponins were investigated.

Seven new triterpenoid saponins, randiasaponins I (1), II (2), III (3), IV (4), V (5), VI (6) and VII (7) as well as two known ones, ilexoside XXVII (8) and ilexoside XXXVII (9), were isolated from the methanolic extract of the leaves of Randia formosa. The structures of the new saponins were established as 3-O-alpha-L-arabinopyranosyl-3 beta,19 alpha,23-trihydroxyursa-12,20(30)-dien-28-oic acid 28-beta-D-glucopyranosyl ester (1), 3-O-beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl rotundic acid (2), 3-O-beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl pomolic acid 28-beta-D-glucopyranosyl ester (3), 3-O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl pomolic acid 28-beta-D-glucopyranosyl ester (4), 3-O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl siaresinolic acid 28-beta-D-glucopyranosyl ester (5), 3-O-alpha-L-arabinopyranosyl ilexosapogenin A 28-beta-D-glucopyranosyl ester (6), and 3-O-beta-D-glucopyranosyl ilexosapogenin A 28-beta-D-glucopyranosyl ester (7), based on spectral and chemical evidence. Besides the saponins, two common flavonoids kaempferol 3-O-rutinoside and rutin were also isolated.

A MeOH extract from Z. africana was examined for topical antiinflammatory activity and proved to be active against arachidonic acid (AA) acute edema, 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced chronic inflammation, and oxazolone delayed-type hypersensitivity in mice. The extract also showed significant inhibitory activity of Naja naja phospholipase A2 when a polarographic method was used. Two oleanane-type triterpene saponins, zanhasaponins A (1) and B (2), and the cyclitol pinitol (4), isolated from the extract, were active as inhibitors of PLA2. A further saponin, zanhasaponin C (3) was inactive in this assay.

Two novel triterpenoid saponins, named mussaendosides U and V, together with one known saponin and four known triterpenes were isolated from the aerial parts of Mussaenda pubescens (Rubiaceae). The structures were determined on the basis of chemical analysis ad spectral methods. All these compounds were identified for the first time from the genus Mussaenda.

Three new saponins, zanhasaponins, A, B, and C, were isolated from the MeOH extract of the root bark of Zanha africana and were, respectively, identified by spectroscopic methods as 3-O-beta-D-glucuronopyranosyl-2 beta,16 alpha-dihydroxyolean-12-ene-23,28- dioic acid 28-O-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-rhamnopyranoside (1); 3-O-beta-D-glucuronopyranosyl-2 beta,16 alpha-dihydroxyolean-12-ene- 23,28-dioic acid 28-O-beta-D-xylopyranosyl(1-->2)-alpha-L-rhamnopyranosyl(1-->2)-alpha-L- rhamnopyranoside (2); and 3-O-beta-D-glucuronopyranosyl-2 beta,16 alpha-dihydroxyolean-12-ene- 23,28-dioic acid 28-O-beta-D-xylopyranosyl(1-->3)-beta-D-xylopyranosyl (1-->2)-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-rhamnopyranoside (3). These saponins proved to be effective in a model of topical inflammation induced by phorbol ester. The cyclitols quebrachitol, pinitol, and bornesitol were also identified.

By means of activity-directed chromatographic fractionation using the 12-O-tetradecanoylphorbol acetate (TPA)-induced edema test, two saikosaponins were isolated from the MeOH extract of Heteromorpha trifoliata leaves. They were identified as 16 beta, 23-dihydroxy-13,28-epoxyolean-11-en-3 beta-yl-[beta-D-glucopyranosyl (1-->2)]-[beta-D-glucopyranosyl (1-->3)]-beta-D-fucopyranoside [1] and 16 beta, 23,28-trihydroxy-11 alpha-methoxyolean-12-en-3 beta-yl-[beta-D-glucopyranosyl (1-->2)]-[beta-D-glucopyranosyl (1-->3) [beta-D-fucopyranoside [2]. Compound 1 showed activity in the TPA and ethylphenylpropiolate (EPP) mouse ear edema and the serotonin paw edema tests, whereas compound 2 was active only in the mouse ear edema model. Both substances had only a slight effect against a carrageenan paw edema model. The anti-inflammatory action of compound 1 was notably decreased by the mRNA and protein synthesis inhibitors actinomycin D and cycloheximide.

The molluscicidal activity of crushed seed pods of Swartzia madagascariensis was assessed by laboratory and field trials. Mature dry seed pods were ground and extracted in tap water for 24 h. Water extracts exerted a significant molluscicidal activity against Bulinus globosus up to dilutions of 100 mg of ground pods per litre. The chromatographically isolated saponin (1) responsible for the molluscicidal activity showed a toxicity of LC 100 at 3 mg/l after exposure of B. globosus and Biomphalaria glabrata for 24 h. Saponin (1) could be identified by FAB-MS and 13C-NMR-spectroscopy as oleanolic acid-3-O-beta-D-glucuronopyranosyl (1----3)-alpha-L-rhamnopyranoside. Two field trials with S. madagascariensis pod extracts in ponds (60 and 160 m3) harbouring dense populations of B. globosus compared well with the laboratory findings and showed the efficiency of the molluscicide in a natural habitat. A single application of the plant molluscicide significantly reduced the populations of B. globusus. The toxicity of S. madagascariensis pod extracts to non-target organisms remains an obstacle for its use in certain situations where schistosomiasis control is envisaged and where S. madagascariensis is found. However, S. madagascariensis is a valid candidate molluscicide which may be applied in selected epidemiological settings as part of integrated schistosomiasis control measures.

A high-performance liquid chromatographic method is described for the determination of oleanane saponins in Phytolacca dodecandra (Phytolaccaceae), a plant with potent molluscicidal properties. The molluscicidal monodesmosidic saponins of the berries were determined at 254 nm as their 4-bromophenacyl derivatives, whereas the non-derivatized bidesmosidic saponins, lacking a free carboxyl group, were determined at 206 nm. A comparison of different extraction procedures showed that with cold water predominantly monodesmosidic saponins were obtained, whereas hot water gave mainly bidesmosidic (non-molluscicidal) saponins.