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Four labdanes with a 8alpha,15-epoxy ring (8alpha,15-epoxylabdan-16beta-oic acid; 8alpha,15-epoxy-16-norlabdan-13-one; 8alpha,15-epoxy-16-norlabdane; and 16-acetoxy-8alpha,15-epoxylabdane) and the known compound ambreinolide were isolated from the hexane extract of the aerial parts of the grass Eragrostis viscosa. The structures of all compounds were established based on spectroscopic data and the X-ray analysis of 8alpha,15-epoxy-16-norlabdan-13-one. The hexane extract presented moderate activity against the snail Biomphalaria glabrata. 8alpha,15-Epoxylabdan-16beta-oic acid showed no mutagenic activity for doses up to 1000 microg/plate and no significant clastogenic activity for doses up to 100 microg/ml.

Solanum aculeastrum Dunal was investigated for the presence of molluscicidal compounds. This led to the isolation of solaculine A, from the root bark in addition to known steroidal alkaloids; solamargine and beta-solamarine from the berries. The structures were elucidated by spectroscopic techniques. Molluscicidal activity of the aqueous extracts of the berries and root bark, and the isolated compounds were investigated.

Snails (Helix aspersa L.) were fed filter paper treated with the potato glycoalkaloids, alpha-solanine and alpha-chaconine, singly or together. In pure form, both glycoalkaloids deterred feeding, with chaconine being the more active compound. In combination, authentic solanine and chaconine interacted synergistically in their inhibition of feeding. The antifeedant activities of methanolic extracts of tuber peel of the potato varieties Majestic and Sharpe's Express presented via filter paper discs did not differ significantly from those of authentic glycoalkaloid solutions of comparable concentration and ratio. In contrast, feeding inhibition by diluted tuber peel extracts of the variety Homeguard was greater than that elicited by comparable authentic glycoalkaloid solutions suggesting additional inhibitory compound(s) in the peel of this variety. Comparison of data from peel extracts of all three potato varieties and authentic glycoalkaloids indicated that the level of feeding inhibition by the extracts was, at least in part, a consequence of a synergism between solanine and chaconine.

Diterpene esters of the phorbol and ingenol types are known to be highly active tumor promoting agents that typically occur in members of the Euphorbiaceae. In the present work, Euphorbia leuconeura, a rare indoor plant, is analyzed for its tumor promoting potential. Latex as well as total leaf extracts exhibited Epstein-Barr-virus (EBV) inducing activity comparable to 12-O-tetradecanoyl-phorbol-13-O-acetate, a well known tumor promoter. The activity of individual fractions correlated with their ingenol ester content. Three ingenol esters with EBV inducing activity could be isolated and identified. They belong to the milliamine type of diterpene esters that contain aromatic peptidyl groups. Two of them (milliamines L and M) are already known from E. milii. The third compound is identified as an isomer of milliamine F with a novel 3,20-diester arrangement. The data show a close relationship between E. leuconeura and the more popular indoor plant E. milii whose latex is also used as a powerful molluscicide.

Two new saponins were isolated from the fruits of Catunaregam nilotica Stapf, syn. Lachnosiphonium nilotica; Randia nilotica; Xeromphis nilotica. Their structures were determined mainly by spectroscopic methods as 3- O-[O-alpha-L-rhamnopyranosyl-(1--3)-O-[O-beta-D-glucopyranosyl-(1 --3)]- beta-D-glucopyranosyl]oleanolic acid and 28-O-beta-D- glucopyranosyl-3-O-[O-alpha-L-rhamnopyranosyl-(1--3)-O[O-beta-D- glucopyranosyl]-beta-D-glycopyranosyl]oleanolate. The monodesmosidic saponin is a potent molluscicide against the schistosomiasis transmitting snail Biomphalaria glabrata with a LC50 value of 3 ppm. In addition two known saponins, 3-O-[2', 3'-di-O-(beta-D-glucopyranosyl)-beta-D- glucopyranosyl]oleanolic acid and 3-O-[O-beta-D-glucopyranosyl(1--3)- beta-D-glucopyranosyl]oleanolic acid, were identified and their molluscicidal activity determined, the LC50 values being 26 and 3 ppm, respectively. Initial molluscicidal screening of the crude water and ethanol extracts revealed 100% snail mortality at concentrations of 100 and 50 ppm, respectively. The haemolytic activity of the molluscicidal saponins was determined as well and the HC50 values towards bovine erythrocytes found to be 3 ppm for the new saponin, and 16 and 2 ppm, respectively, for the two known saponins.

From the latex of Euphorbia milii var. hislopii collected in Brazil, eight milliamines were isolated using a bioassay-guided protocol based on molluscicidal activity. Three were known milliamines A, D and E, the other five being new compounds of this class. Milliamine L, a dianthraniloyl peptide ester of ingenol, was found to be molluscicidal at 4 nM (2.5 μg 1 −1 ).

From the methanolic extract of leaves of Rapanea melanophloeos , a molluscicidal and antifungal triterpenoid saponin has been isolated and identifie

A novel sesquiterpene lactone, podoandin, has been isolated from the leaves of Podocarpus andina. Its structure has been established by means of spectroscopic data and confirmed by X-ray diffraction analysis. It exhibited moderate molluscicidal activity as well as other biological activities.

From the methanolic extract of roots of Clerodendrum wildii , a molluscicidal and antifungal triterpenoid saponin has been isolated and identified as Mi-saponin A by spectral analysis and chemical transformations.

Four triterpenoid saponins isolated from the leaves of Polyscias dichroostachya were identified as 3-O-[α- l -arabinopyranosyl]-hederagenin, 3-O-[α- l -rhamnopyranosyl-(1→2)-α- l -arabinopyranosyl]-hederagenin, 3-O-[β- d -glucopyranosyl-(1→2)-α- l -arabinopyranosyl]-hederagenin, 3-O-[α- l -rhamnopyranosyl-(1→2)-α- l -arabinopyranosyl]-hederagenin 28-O-β- d -glucopyranoside. The three monodesmosidic saponins were found to possess strong molluscicidal activity against the schistosomiasis-transmitting snails Biomphalaria glabrata, whereas the bidesmosidic saponin, a new natural product, was inactive.

Daily variation in the content of the saponins of the berries of Phytolacca dodecandra was determined in berries harvested at the full grown green unripe stage of development once every two hours. The saponin content was quantitatively determined by HPLC analysis of the molluscicidal monodesmosidic saponins in the aqueous extract of the crushed berries. No significant daily variations were observed in extracts of berries collected at different times of day (P> 0.05 by ANOVA). But, seasonal variation was apparent in extracts prepared from berries harvested from the same plants once every two weeks. Berries of highest saponin content were those harvested during the dry season and just before the onset of the rainy season. The seasonal variation was attributed to increased water stress during the dry season. Very young racemes had the highest saponin content, while mature berries produced the lowest saponin concentration. There was, however, consistency in the berry saponin composition during the day, season and all stages of berry development.

A new, homoerythrina-derived alkaloid with molluscicidal activity, lenticellarine, was isolated from the leaves of Dysoxylum lenticellare and its structure was determined by spectroscopic methods.

One monodesmosidic saponin and six bidesmosidic saponins have been isolated from the methanolic extract of the leaves of Swartzia simplex . They were shown to be glucuronides of oleanolic acid, gypsogenin and gypsogenic acid by chemical and spectral means. The monodesmosidic saponins exhibit various molluscicidal activities against the schistosomiasis-transmitting snail Biomphalaria glabrata .

From the roots of Gundelia tournefortii seven saponins have been isolated mainly by DCCC. The main saponins (A and B) were characterized, mainly by 13C and 1H NMR spectroscopy, as oleanolic acid 3-O-(2-[α- l -arabinopyranosyl(1 → 3) -β- d -gentiotriosyl(1 → 6) -β- d -glucopyranosyl]gb- d -xylopyranoside) (saponin A) and oleanolic acid 3-O-(2-[α- l -arabinopyranosyl] (1 → 3)-β- d -gentiobiosyl (1 → 6)-β- d -glucopyranosyl β- d -xylopyranoside) (saponin B). The other saponins are also derived from oleanolic acid and contain more sugar units. The saponin mixture and the saponins A and B possess strong molluscicidal activity against the schistosomiasis transmitting snail Biomphalaria glabrata.

The chemical investigation of the extractives of Calophyllum verticillatum provided three new neoflavonoids: caloverticillic acids A, B and C, in addition to α-amyrin and friedelin. Molluscicidal activity against Biomphalaria glabrata was observed.

The structure of one of the major molluscicidal saponins of the fruit of Phytolacca dodecandra has been elucidated as 3-[2,4-di-O-(β- d- glucopyranosyl)-β- d -glucopyranosyll-olean-12-ene-28-oic acid. The combined use of 300 Mc. PMR, MS and GC-MS led to this structural assignment.

Two saponins are responsible for the molluscicidal activity of an extract of the stem bark of Cussonia spicata. Their structures have been established as [α- L -arabinofuranosyl-(1 → 4)-β- D -glucuronopyranosyl-(1 → 3)]-3β-hydroxyolean-12-en-28-oic acid and [(α- L -arabinofuranosyl-(1 → 4)-β- D -galactopyranosyl-(1 → 2))-β- D -glucuronopyranosyl-(1 → 3)]-3β-hydroxyolean-12-en-2

Three saponins with molluseicidal and fungicidal activities have been isolated from the roots of Dolichos kilimandscharicus . They were shown to be the 3- O -β- d -glucopyranosides of hederagenin, bayogenin and medicagenic acid.