Anti-mosquito and antimicrobial nor-halimanoids, isocoumarins and an anilinoid from Tessmannia densiflora

Kihampa, Charles; Nkunya, Mayunga H.H.; Joseph, Cosam C.; Magesa, Stephen; Hassanali, Ahmed; Heydenreich, Matthias; Kleinpeter, Erich

doi:10.1016/j.phytochem.2009.07.024

Cited by 31 publications

(30 citation statements)

References 8 publications

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“…The compound tessmannic acid was nearly three times more active than its methyl ester, methyltessmannoate, with an LC 50 value of 244 ppm after a 24-h exposure (Kihampa et al 2009). Bioassay-guided fractionation and subtraction bioassays of the dichloromethane extract of the root barks of Lantana viburnoides sp.…”

Section: Discussionmentioning

confidence: 98%

Biolarvicidal compound gymnemagenol isolated from leaf extract of miracle fruit plant, Gymnema sylvestre (Retz) Schult against malaria and filariasis vectors

Khanna

Каннабиран

Rajakumar³

et al. 2011

Parasitol Res

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Owing to the fact that the application of synthetic larvicide has envenomed the surroundings as well as non-target organisms, natural products of plant origin with insecticidal properties have been tried as an indigenous method for the control of a variety of insect pests and vectors in the recent past. Insecticides of plant origin have been extensively used on agricultural pests and, to a very limited extent, against insect vectors of public health importance, which deserve careful and thorough screening. The use of plant extracts for insect control has several appealing features as these are generally more biodegradable, less hazardous and a rich storehouse of chemicals of diverse biological activities. Moreover, herbal sources give a lead for discovering new insecticides. Therefore, biologically active plant materials have attracted considerable interest in mosquito control study in recent times. The crude leaf extracts of Gymnema sylvestre (Retz) Schult (Asclepiadaceae) and purified gymnemagenol compound were studied against the early fourth-instar larvae of Anopheles subpictus Grassi and Culex quinquefasciatus Say (Diptera: Culicidae). In the present study, bioassay-guided fractionation of petroleum ether leaf extract of G. sylvestre led to the separation and identification of gymnemagenol as a potential new antiparasitic compound. Phytochemical analysis of G. sylvestre leaves revealed the presence of active constituents such as carbohydrates, saponins, phytosterols, phenols, flavonoids and tannins. However, cardiac glycosides and phlobatannins are absent in the plant extracts. Quantitative analysis results suggested that saponin (5%) was present in a high concentration followed by tannins (1.0%). The 50 g powder was loaded on silica gel column and eluted with chloroform-methanol-water as eluents. From that, 16 mg pure saponin compound was isolated and analysed by thin layer chromatography using chloroform and methanol as the solvent systems. The structure of the purified triterpenoid fraction was established from infrared (IR), ultraviolet (UV), (1)H nuclear magnetic resonance (NMR), (13)C NMR and mass spectral data. The carbon skeleton of the compound was obtained by (13)C NMR spectroscopy. The chemical shift assignments obtained for gymnemagenol from (1)H NMR correspond to the molecular formula C(30)H(50)O(4). The compound was identified as 3β, 16β, 28, 29-tetrahydroxyolean-12-ene (gymnemagenol sapogenin). Parasite larvae were exposed to varying concentrations of purified compound gymnemagenol for 24 h. The results suggested that the larval mortality effects of the compound were 28%, 69%, 100% and 31%, 63%, 100% at 6, 12 and 24 h against A. subpictus and C. quinquefasciatus, respectively. In the present study, the per cent mortality were 100, 86, 67, 36, 21 and 100, 78, 59, 38 and 19 observed in the concentrations of 1,000, 500, 250, 125 and 62.75 ppm against the fourth-instar larvae of A. subpitcus and C. quinquefasciatus, respectively. The purified compound gymnemagenol was tested in concentrations of 8...

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Section: Discussionmentioning

confidence: 98%

Biolarvicidal compound gymnemagenol isolated from leaf extract of miracle fruit plant, Gymnema sylvestre (Retz) Schult against malaria and filariasis vectors

Khanna

Каннабиран

Rajakumar³

et al. 2011

Parasitol Res

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“…These include ent-clerodanoid compounds 18-oxocleroda-3,13(E)-dien-15-oic acid and ent-(18-hydroxy-carbonyl)-cleroda-3,13(E)-dien-15-oate, 2-oxo-ent-cleroda-3,13(Z)-dien-15-oic acid and cis- 2-oxo-ent-cleroda-13(Z)-en-15-oic acid, and O-(3-hydroxy-4-hydroxycarbonyl-5-pentylphenyl)-3-chloro-4-methoxy-5-pentyl-2-oxybenzoic acid from Tessmannia martiniana var pauloi and T. martiniana var martiniana, respectively (Kihampa et al, 2010). Tessmannia densiflora yielded larvicidal compounds nor-halimanoid diterpenoids tessmannic acid and methyltessmannoate (Kihampa et al, 2009a). The antimosquitocidal phenylpropenoids Omethyleugenol, O-methylisoeugenol and 2,3-dimethoxycinnamaldehyde were from the stem and root bark extracts of Uvariodendron pycnophyllum (Diels) R.E.…”

Section: Mosquito Repellency Bioassaysmentioning

confidence: 99%

Tanzanian Botanical Derivatives in the Control of Malaria Vectors: Opportunities and Challenges

Kihampa¹

2011

Journal of Applied Sciences and Environmental Management

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This paper report on assessment of the chemicals derived from Tanzanian botanical resource as a viable source of safe, environmentally friendly and low cost mosquitocidal agents, but has yet to be developed into simple blends and formulations to be used in malaria control campaigns. Selection of bioactive plant species were based on random screening, phytochemical targeting, ethnobotanical survey, chemotaxonomic approach and targeted screening approach. The crude extracts from leaves, stem and root barks, and pure isolated compounds from over 20 different Tanzania plant species have been established to possess antimosquito activities. The bioassay experiments were based on cytotoxicity screening in BST followed by mosquitocidal assays of larvicidal, tarsal contact and repellency bioassays. The activities were characterized to be larvicidal, growth disruptors, insecticidal and repellents. Seasonal variations, geographical locations, isolation of small amounts of pure compounds, limits in the availability of essential facilities such as NMR spectroscopy, MS and X-ray diffraction analysis for structural elucidation, stereochemical and conformational assignments, have been realised to be among the impediments in the search and establishment of new and biodegradable botanical natural products. The results suggest that the investigated plant species are promising as mosquitocidal agents and could be useful leads for the development of new insecticide products. @JASEM

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“…The isolated compounds were identified as nor-halimane diterpenoid tessmannic acid and its methyl, 2-methylisopropyl and 1-methylbutylesters, 5-pentyl-3-methoxy-N-butylaniline, and two unusual isocoumarins. The structures of the new isocoumarins were established unambiguously as 8-hydroxy-6-methoxy-3-pentyl-1H-isochromen-1-one ( Figure 1) and 7-chloro-8-hydroxy-6-methoxy-3-pentylisocoumarin, respectively, by analysis of spectroscopic data [8].…”

Section: Introductionmentioning

confidence: 97%

“…During investigations for botanical insecticides for the control of malaria-transmitting Anopheles gambiae mosquitoes, Nkunya and coworkers [8] isolated a number of compounds from the stem and root bark extracts of Tessmannia densiflora Harms (family Caesalpiniaceae) that showed mosquito larvicidal activity. The isolated compounds were identified as nor-halimane diterpenoid tessmannic acid and its methyl, 2-methylisopropyl and 1-methylbutylesters, 5-pentyl-3-methoxy-N-butylaniline, and two unusual isocoumarins.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of 8-hydroxy-6-methoxy-3-pentyl-1H-isochromen-1-one from Tessmannia densiflora

Saeed

2011

Eur. J. Chem.

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Anti-mosquito and antimicrobial nor-halimanoids, isocoumarins and an anilinoid from Tessmannia densiflora

Cited by 31 publications

References 8 publications

Biolarvicidal compound gymnemagenol isolated from leaf extract of miracle fruit plant, Gymnema sylvestre (Retz) Schult against malaria and filariasis vectors

Biolarvicidal compound gymnemagenol isolated from leaf extract of miracle fruit plant, Gymnema sylvestre (Retz) Schult against malaria and filariasis vectors

Tanzanian Botanical Derivatives in the Control of Malaria Vectors: Opportunities and Challenges

Synthesis of 8-hydroxy-6-methoxy-3-pentyl-1H-isochromen-1-one from Tessmannia densiflora

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