Molluscicidal constituents of Calophyllum from Madagascar: activity of some natural and synthetic neoflavonoids and khellactones.

Crude extracts of seeds, leaves and barks of four Madagascan Calophyllum species: C. inophyllum, C. recedens, C. chapelieri, and C. verticullatum, have been tested for molluscicidal activity against Biomphalaria glabrata. All seed extracts showed significant activity. The major constituents of the most active Calophyllum species were examined. Some related coumarinic derivatives were synthesized in order to improve the biological activity. Among the compounds prepared, 5,7-dihydroxy-6-(2-methylbutyryl)-4-phenyl-coumarin presented an interesting molluscicidal activity.     

Molluscicidal and antischistosomal activities of Zingiber officinale

Experiments were conducted to study the major constituents of Zingiber officinale responsible for its molluscicidal activity and the effect of the active component on different stages of Schistosoma mansoni. Gingerol and shogaol exhibited potent molluscicidal activity on Biomphalaria glabrata. Gingerol (5.0 ppm) completely abolished the infectivity of Schistosoma mansoni miracidia and cercariae in B. glabrata and mice, respectively, indicating that the molluscicide is capable of interrupting schistosome transmission at a concentration lower than its molluscicidal concentrations.     

Ambrosia maritima L.: study of molluscicidal properties of several generations originating in Egypt and cultivated in Senegal

The authors experiment molluscicidal properties of Ambrosia maritima L. from Egypt and cultivated in Senegal. Four generations are tested. Six plants, on eight tested, had same molluscicidal activity as the strain in Egypt.     

The molluscicidal activity of coumarins from Ethulia conyzoides and of dicumarol.

The molluscicidal principles of Ethulia conyzoides were identified as ethuliacoumarin A (1) and isoethuliacoumarin A (2). Ethuliacoumarin A possessed an LC90 between 19 and 23.5 ppm depending on the age of the snail against Biomphalaria glabrata, and between 12 and 15 ppm against Bulinus truncatus. In addition, ethuliacoumarin A was found to be cercaricidal at 25 ppm and ovicidal. Ethuliacoumarin has the structural requirements considered essential for anticoagulant activity. Consequently the anticoagulant dicumarol (4) was tested and found to be molluscicidal in the range from 2.5 to 10 ppm. In contrast, the coumarin anticoagulant warfarin (3) did not show molluscicidal activity.     

Glaucolide B, A Molluscicidal Sesquiterpene Lactone, and Other Constituents of Vernonia eremophila

The sesquiterpene lactone glaucolide B was isolated from the molluscicidal extract of VERNONIA EREMOPHILA Mart, and shown to be responsible for the molluscicidal activity. Hydrogenolysis of glaucolide B resulted in the disappearance of the activity. Other inactive constituents of the extract were 3,7-dimethoxy-5,3',4'-trihydroxyflavone and two transformation products, possibly artefacts, of glaucolide B. Glaucolide B exhibited strong antimicrobial activity against B, CEREUS and moderate activity against S. AURENS, but was inactive in several other systems.     

Molluscicidal properties of various saponins

A series of 24 different saponins isolated from various medicinal plants have been tested against BIOMPHALARIA GLABRATA, one of the snail vectors of schistosomiasis (bilharziasis). In general, monodesmosidic triterpenoid saponins exhibit strong molluscicidal activity whereas bidesmosidic saponins as well as the aglycones are fully inactive. Some dammarane glycosides and alkaloidal saponins have also been tested.     

Toxicity and mutagenicity of the molluscicidal plant Ambrosia maritima L.

The acute and subchronic toxicity of the molluscicidal plant, Ambrosia maritima L., has been tested on rats. No toxic signs could be detected neither after oral administration of 5 g/kg of dried leaves of the plant as a powder or as a methanolic extract, nor after the incorporation of 50,000 ppm powdered leaves in the feed during 4 weeks. Using an aqueous extract of the plant material of A. maritima or using ambrosin, one of the active molluscicidal components of the plant, no mutagenic activity could be detected in the S. typhimurium strains TA97, TA 98, TA1538, TA100 and TA1535.     

Synthesis and molluscicidal activity evaluation of some nitrosalicylanilides

The hitherto unknown 5,6-dinitrosalicylic acid has been obtained as a by-product during nitration of salicylic acid. Synthesis of some 3-nitro-, 5-nitro- and 5,6-dinitrosalicylanilides with different substituents on the amine moiety was carried out. Evaluation of the molluscicidal activity of the synthesised salicylanilides is discussed.     

Screening of Panamanian Plants for Molluscicidal Activity

A total of 153 crude extracts of Panamanian plants (28 species from 21 families) have been screened for molluscicidal activity against Biomphalaria glabrata, one of the intermediate hosts of schistosomiasis. When tested at 400 ppm, 15 extracts were active. The most potent of these came from Cyperus luzulae (Cyperaceae) and Hymenaea courbaril (Leguminosae).     

Evaluation of the mutagenic potential of endod (Phytolacca dodecandra), a molluscicide of potential value for the control of schistosomiasis

Extracts of the fruit of Phytolacca dodecandra (endod) demonstrate molluscicidal and other biological activities. Since this plant is indigenous to some countries where schistosomiasis is a common problem, it has been proposed that it may be socioeconomically feasible to employ endod as an aid in the control of this disease through its use to control the snail vector. As an initial step in the safety assessment of this substance, its mutagenic potential was determined utilizing Salmonella typhimurium strain TM677. The seeds and fruit of Phytolacca americana, also molluscicidal, were additionally evaluated for mutagenic potential. Using a variety of conditions, no mutagenic activity could be demonstrated for any of the extracts tested. Thus, subject to the results of future safety assessment, endod remains a viable candidate as a useful molluscicide.     

On the molluscicidal activity of tannin containing plants

The aqueous and methanolic extracts of a series of typical tannin containing plants exhibit strong molluscicidal properties against the freshwater snail biomphalaria glabrata, which is the intermediate host of schistosomiasis. The crude extracts of Krameria triandra (Krameriaceae) and Arctostaphylos uvaursi (Ericaceae) were active at concentrations of 50 ppm. Hydrolyzable and condensed tannins are responsable for the molluscicidal activity. This report indicates a new class of plant derived compounds which may have important practical application for the control of schistosomiasis in endemic areas.     

Anthelmintic properties of Polygonum glabrum

A pure anthelmintic substance (PGA) has been isolated from the methanol-aqueous extract of the leaf of Polygonum glabrum Willd., a semi-aquatic Sudanese species of the family Polygonaceae. The antiparasitic in-vitro activity of several fractions isolated from the plant, has been examined comparatively with that of PGA. PGA also showed molluscicidal activity against Biomphalaria glabrata and Limnea truncatula Müll. Structural determination of PGA was attempted following data analysis of UV, IR, 13C NMR, 1H NMR and MS spectra and suggests that PGA is a terpenoid.     

Molluscicidal properties of Acacia nilotica

The acetone, alcohol and aqueous extracts of fruits of Acacia nilotica (L) Willd. ex Del. (Mimosaceae) showed molluscicidal activity against Bulinus truncatus and Biomphalaria pfeifferi, the two snail species which transmit schistosomiasis in the Sudan (S. haematobium and S. mansonii). TAN, a new vegetable molluscicide prepared from the aqueous extract of the fruits of A. nilotica was produced on a pilot scale by using the spray drying procedure. Due to the high content of tannins in the powder (more than 56%), the molluscicidal properties of this plant may well be due to these compounds.     

Molluscicidal Properties of Acacia nilotica.

The acetone, alcohol and aqueous extracts of fruits of ACACIA NILOTICA (L) W ILLD. ex D EL. (Mimosaceae) showed molluscicidal activity against BULINUS TRUNCATUS and BIOMPHALARIA PFEIFFERI, the two snail species which transmit schistosomiasis in the Sudan (S. haematobium and S. mansonii). TAN, a new vegetable molluscicide prepared from the aqueous extract of the fruits of A. NILOTICA was produced on a pilot scale by using the spray drying procedure. Due to the high content of tannins in the powder (more than 56%), the molluscicidal properties of this plant may well be due to these compounds.     

The toxic activities of Arisaema erubescens and Nerium indicum mixed with Streptomycete against snails

The comparative molluscicidal activities of Arisaema erubescens tuber extracts and Nerium indicum leaf extracts mixed with Streptomycete violacerruber dilution (SD) against the snail Oncomlania hupensis and the responses of the isozymes, esterase (EST) and superoxide dismutase (SOD) to the A. erubescens extracts and the mixtures were investigated. The molluscicidal activity of A. erubescens water extracts mixed with S. violacerruber dilution was 4-5 times higher than a single A. erubescens or S. violacerruber dilution after 24-h exposure, and is also higher than that of N. indicum leaf water extracts mixed with S. violacerruber dilution. At the end of exposure to the N-butanol extracts of A. erubescens tubers (NEAT), the EST activity in snail liver decreased and some enzyme bands (EST 1 and EST 3 in exposure to NEAT) disappeared but the activities of SOD 1 increased. The effect was more obvious in mixture treatment than in single NEAT or SD treatment. The results indicated that molluscicidal activities of plant and microorganism could be more effective than single plant. The decline of the detoxic ability in snail liver cells could be the reason of the snail dying.     

Synthesis of furo-salicylanilides and their heterocyclic derivatives with anticipated molluscicidal activity

The synthesis of new furo-salicylanilides and their heterocyclic derivatives is described. Twenty-three compounds were screened for their molluscicidal activity against Biomphalaria alexandrina snails, the intermediate host of Schistosoma mansoni. Five of the tested compounds showed no activity, while eighteen compounds showed strong to moderate activity using bayluscide as a reference.     

Molluskizid wirksame Spiro-α-methylen-γ-butyrolactone

α-Methylene-γ-butyrolactones with Molluscicidal Activity The α-methylene-γ-butyrolactones 1-28 were tested in vitro for molluscicidal activity against Biomphalaria glabrata. The racemic compound 25 shows the best activity. The synthesis was carried out by modified Reformatzky reaction of the corresponding carbonyl compounds and bromomethylacrylic acid ethyl ester. 7-10, 17 and 22-27 have been synthesized for the first time.     

Synthesis and molluscicidal activity of 5-oxo-5,6,7,8-tetrahydro-4H-chromene derivatives

Furfurylidenemalononitriles and thienylidenemalononitriles were treated with 1,3-cyclohexanediones to afford 2-amino-4-hetaryl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile derivatives. The molluscicidal activity of these compounds was investigated.     

Molluscicidal activity and clinico-pathological effect ofAgave lophantha

Dry powder and different extracts of Agave lophantha were tested against Biomphalaria alexandrina. The results showed that the butanol extract has high molluscicidal activity. The activity of the dry powder has been found to be stable under the effect of some simulated field conditions. Also the toxicological effect of the plant on mice was tested through determination of certain parameters such as total protein, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and acid phosphatase enzymes as well as histopathological study on liver and kidney.     

Investigations of Molluscicidal Activity of Certain Sudanese Plants Used in Folk-Medicine. Part IV*

50 plants indigenous to the Sudan and of common use in Sudanese folk-medicine, were screened for their molluscicidal activity, using two local snail vectors, BULINUS TRUNCATUS and BIOMPHALARIA PFEIFFERI. At different concentrations 31 (62%) of these plant samples were found to be lethal to either one or both of the snail species. 28 (56%) proved to be lethal to BIOMPHALARIA PFEIFFERI, 22 (44%) gave 100% mortality to BULINUS TRUNCATUS; while 19 (38%) killed both snail hosts (Table I). The seven most active molluscicidal plants were phytochemically screened for their active constituents; four of them showed the presence of saponins.