Muthuswami Kalyanasundaram

Indian Council of Medical Research | ICMR · Department of Chemistry

Preclinical Research Lymphatic filariasis is a disfiguring disease caused by parasitic worms that destroy the human lymphatic system leading to substantial morbidity. The current drug of choice for the treatment of filariasis is diethylcarbamazine and ivermectin with albendazole which are only effective against the microfilaria, leaving the adult...

Aedes aegypti is the key vector of three important arboviral diseases -dengue, yellow fever and chikungunya. To identify volatile chemicals which could be used in odour based traps for Aedes mosquito surveillance, a few synthetic compounds and compound blends have been evaluated in an indigenously designed olfactometer. A total of 24 compounds and...

Eleven 1,4-naphthoquinone analogues with different amino substitutions at position 3 of the quinone ring earlier reported for macrofilaricidal activity were selected and screened against purified cytosolic GST isolated from the bovine filarial worm Setaria digitata and IC(50) values were determined. Of the 11 compounds tested, 8 showed good inhibit...

Setaria digitata is a filarial worm of the cattle used as a model system for antifilarial drug screening, due to its similarity to the human filarial parasites Wuchereria bancrofti and Brugia malayi. Since filarial glutathione S-transferase (GST) is a good biochemical target for antifilarial drug development, a study has been undertaken for the bio...

DPE-28, a substituted diphenyl ether (2,6-ditertiarybutyl phenyl-2',4'-dinitro phenyl ether) was reported to exhibit promising insect growth regulating activity against Culex quinquefasciatus, the vector of lymphatic filariasis. A controlled release formulation (CRF) of DPE-28 has been developed to control Cx. quinquefasciatus in its breeding habit...

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Pirimiphos-methyl, an organophosphorus insecticide is known to overcome resistance mechanisms of mosquitoes to other organophosphates. Information on the duration of efficacy of pirimiphos-methyl (50% emulsifiable concentrate) for the control of immatures of Culex quinquefasciatus, the vector of bancroftian filariasis, is scanty and hence site spec...

Vector control, using agents of chemical origin, continues to be practiced in the control of vector borne diseases. However, due to some drawbacks including lack of selectivity, environmental contamination, and emergence and spread of vector resistance, development of natural products for vector control has been a priority in this area. In the pres...

Female adult bovine filarial worms Setaria digitata were extracted with phosphate-buffered saline (pH 7.4) and glutathione S-transferase (GST) activity and protein content were determined. The protein content, GST enzyme activity, and specific activity were 10.61 +/- 3.41 mg ml(-1), 0.09 +/- 0.019 micromol min(-1) ml(-1), and 0.009 +/- 0.002 microm...

There is no safe and effective drug for killing the adult worms for the elimination/control of lymphatic filariasis and research is very much warranted towards the development of a macrofilaricidal drug. Therefore, the synthesis and evaluation of 1-N-methyl-substituted benzoyl/phenyl acetyl piperazides for macrofilaricidal activity were carried out...

Eleven amino-substituted 1,4-naphthoquinones were synthesized via the reaction of 1,4-naphthoquinone with different primary and secondary mono- and diamines in the presence of dichloromethane ethanol (1:2) solvent at room temperature. All compounds were purified by flash column chromatography, characterized by TLC, HPLC, 13C-NMR, 1H-NMR, and FT-IR...

Screening of natural products for mosquito larvicidal activity against three major mosquito vectors Aedes aegypti, Culex quinquefasciatus, and Anopheles stephensi resulted in the identification of three potential plant extracts viz., Saraca indica/asoca, Nyctanthes arbor-tristis, and Clitoria ternatea for mosquito larval control. In the case of S....

Insecticide treated mosquito nets are increasingly being used in malaria control programmes. One of the problems with the treatment of bed nets with conventional formulations of insecticides was that regular washing of treated nets diminish insecticidal effect. Lambdacyhalothrin 2.5 capsule suspension (CS) (2.5% a.i., w/v), a new water-based microe...

Lymphatic filariasis is caused by infection with the parasitic filarial nematodes Wuchereria bancrofti, Brugia malayi and B. timori, transmitted by mosquitoes. The lack of an adulticidal drug poses a challenge to filariasis elimination, hence it is essential to develop an effective antifilarial drug which could either kill or permanently sterilize...

Lymphatic filariasis and river blindness (onchocerciasis) are two important tropical diseases caused by infections with filarial nematodes, resulting in considerable morbidity. Onchocerciasis is caused by infection with the nematode worm Onchocerca volvulus, which is transmitted by blackflies. Lymphatic filariasis is caused by infection with the pa...

Methanolic extracts of 20 medicinal plants were screened at 1-10 mg/ml for in vitro macrofilaricidal activity by worm motility assay against adult Setaria digitata, the cattle filarial worm. Four plant extracts showed macrofilaricidal activity by worm motility at concentrations below 4 mg/ml and an incubation period of 100 min. Complete inhibition...

Repellents play an important role in protecting humans from the bites of insect pests. An effective and safe repellent will be useful in reducing human-vector contact and thereby help in the interruption of vector borne disease transmission. Because of the unavailability of m-toluic acid in India for the manufacture of N,N-diethyl m-toluamide (DEET...

The glutathione S-transferases (GSTs; EC 2.5.1.18) comprise a family of widely distributed Phase II detoxication enzymes that catalyse the conjugation of a broad variety of reactive electrophiles to the nucleophilic sulfur atom of the major intracellular thiol, the tripeptide glutathione. The diverse functions, including catalytic GSH conjugation,...

Insecticide in the form of space spray as an ultra low volume (ULV) aerosol are used during epidemics of vector borne diseases. Deltacide, a formulation comprising of three chemicals viz., deltamethrin 0.5 per cent w/v, S-bio-allethrin 0.71 per cent w/v and piperonyl butoxide 8.9 per cent w/v is suitable for ULV application. As this combination is...

In cockroach control, bait formulations are extensively used. Fipronil is one of the broad spectrum insecticides from phenyl pyrazole family available in bait formulation. The compound has been tested under field conditions. However, information on its effectiveness on different surfaces and at various density levels is not known. Therefore, the ef...

A three dimensional structural model of Glutathione-S-transferase (GST) of the lymphatic filarial parasite Wuchereria bancrofti (wb) was constructed by homology modeling. The three dimensional X-ray crystal structure of porcine π-class GST with PDB ID: 2gsr-A chain protein with 42% sequential and functional homology was used as the template. The mo...

The use of ecofriendly biodegradable controlled-release formulations of mosquito larvicides could reduce the frequency of application and losses due to degradation of the insecticide compared with conventional formulations. Among the 20 matrices developed by entrapping the organophosphorus mosquito larvicide, fenthion, in carboxymethylcellulose ion...

Methanolic extracts of the leaves of Atlantia monophylla (Rutaceae) were evaluated for mosquitocidal activity against immature stages of three mosquito species, Culex quinquefasciatus, Anopheles stephensi, and Aedes aegypti in the laboratory. Larvae of Cx. quinquefasciatus and pupae of An. stephensi were found more susceptible, with LC50 values of...

The impact of use of bed-nets treated with alphacypermethrin, at 20 mg (ai)/m2, in comparison to untreated nets or no nets on malaria vectors and malaria incidence was studied in tribal villages of Malkangiri district, Orissa state, India, which are highly endemic for falciparum malaria. Treated or untreated nets were supplied to the villagers in J...

The macrofilaricidal property of the plant, Plumbago indica/rosea, was investigated in vitro against Setaria digitata, a filarial parasite of cattle. Adult worms were incubated in a medium containing crude extract at concentrations 0.05, 0.04, 0.02, and 0.01 mg mL−1 for various incubation periods of 30 min, 1 h, 2 h, and 6 h, respectively, at 37°C...

The insect repellent N, N-diethylphenyl acetamide (DEPA) was compared with neem oil, a commercial preparation, for protection against 3 day old un-fed female of the sandfly, Phlebotomus papatasi, (Diptera: Psychodidae) under laboratory conditions on mouse. The percentage protection against sandfly bite provided by neem oil was significantly higher...

A simple and reproducible method for the estimation of diethylcarbamazine citrate (DEC) by high performance liquid chromatography (HPLC) in DEC-medicated salt was developed. HPLC analysis was conducted with a mobile phase containing acetonitrile/phosphate buffer (20 mM KH2PO4, adjusted to pH 3.2 with 10% ortho-phosphoric acid) in the ratio of 1:9 a...

Review of literature indicates that none of the chemicals so far studied for oviposition attractancy was found to be promising for operational use. Efforts are being made to find an effective substance to corner a large number of ovipositing females to selective breeding sites for ease of control operation. This will reduce insecticidal consumption...

Repellents can play a useful role in reducing the man-vector contact and help in interrupting disease transmission. Newer formulations are necessary to improve the efficacy of the repellent on the treated sites for enhanced protection. To determine the comparative efficacy, 20 per cent liposphere lotion formulation and 20 per cent alcohol solution...

Studies on the effect of a juvenoid, DPE-28 (2,4-dinitrophenyl-2',6'-di-tertiarybutyl phenyl ether) on biology and behaviour of Cx. quinquefasciatus showed that the developmental duration, sex ratio, mating success and blood feeding were considerably affected by the exposure of larvae and pupae to the compound. Exposure of fourth instar larvae to 0...

The efficacy of aqueous suspension (AS) and granular (G) formulation of Bacillus thuringiensis var. israelensis (Vectobac) was tested against the immatures of mosquito vectors in the laboratory and under field conditions. Laboratory tests showed that the aqueous suspension was relatively more effective against Culex quinquefasciatus than Aedes aegy...

Spicbiomoss, an aqueous suspension formulation of Bacillus sphaericus was evaluated for its efficacy against immatures of Culex quinquefasciatus at the application rate of 120 l/ha in cement tanks, cesspits and drains in Pondicherry and in drains in Kochi, Kerala. The formulation was also tested against anophelines (Anopheles fluviatilis and An. cu...

Controlled release monolithic formulation of fenthion, an organophosphorus mosquito larvicide, prepared by the physical entrapment of the active agent into biodegradable polymer matrices was evaluated against Mansonia mosquito larvae breeding in hydrophytes infested coconut husk retting ponds. Field evaluation was carried out at two application rat...

Residual efficacy of synthetic pyrethroids, viz, permethrin, deltamethrin, lambdacyhalothrin and an insect repellent DEPA in cotton fabrics of different hydrophobicity was tested against Aedes aegypti. Amino silicone was used for enhancing the hydrophobicity of the fabrics. The results showed that there was an increasing trend in repellency/feeding...

QSAR studies in relation to three physicochemical substituent parameters, lipophilicity, electronic and steric factors have been carried out with pyrethroid esters derived from substituted 3-methyl-2-phenoxybutanoic acids against Culex quinquefasciatus applying multiple regression analysis by grouping the esters into three based on their alcohol mo...

Water insoluble matrices of carboxymethylcellulose were made by the ionotropic crosslinking of sodium carboxymethylcellulose with cupric or ferric ions. Matrices were also made containing an interactive polymer, gelatin in combination with sodium carboxymethylcellulose. The surface texture of the matrices was analysed by scanning electron microscop...

Thermal analysis of controlled-release formulations of fenthion, prepared by its entrapment in cross-linked carboxymethylcellulose and carboxymethylcellulose–gelatin matrices was carried out by thermogravimetric analysis and under accelerated storage conditions. Thermograms of samples of sodium carboxymethylcellulose, cross-linked polymer samples,...

The insect repellent N,N-diethylphenylacetamide (DEPA) was compared with two commercial repellents, N,N-diethyl-m-toluamide (DEET) and dimethyl phthalate (DMP), for protection against 3-day-old unfed females of the sandfly Phlebotomus papatasi (Scopoli) under laboratory conditions, using host rabbits. Both DEPA and DEET were found to be more effect...

Controlled release formulations of fenthion (10 and 20%) were prepared with sodium carboxyme-thylcellulose and an interactive polymer, gelatin below its isoelectric point followed by crosslinking with cupric ion. The formulations were analysed in the laboratory to monitor the physical integrity of the matrices and release profile of fenthion in wat...

Hydrophilic sodium carboxymethylcellulose (NaCMC) matrices were chemically modified into hydrophobic gels by ionotropic crosslinking with cupric or ferric ion under ambient temperature and pH. Insoluble matrices were also prepared using an interactive polymer gelatin in combination with NaCMC. These matrices underwent erosion at the crosslinks, fol...

Different Electric-Mat-Device (EMD) vaporizers and bioallethrin impregnated mats were evaluated for the knockdown and mortality in the adults of Culex quinquefasciatus, Anopheles stephensi and Aedes aegypti. Percentage knockdown of 80-100 was recorded throughout the test period of 11 hours. However, the percentage mortality observed was not appreci...

Controlled release formulations of a mosquito iarvicide Fenthion® as monolithic slabs were made by insolubilizing sodium carboxymethylcellulose by the ionotropic cross-linking with ferric chloride under ambient conditions of temperature and pH. Slabs containing 20% and 10% larvicide concentrations and three different extents of cross-linking were m...

A preliminary evaluation was undertaken on the safety aspects in mosquito net impregnation with lambdacyhalothrin, on the operators and users of the treated nets. The detection by HPLC of one of the principal metabolites of lambdacyhalothrin, 3-phenoxy benzoic acid (3-PBA) in blood samples of the users and operators in very small quantities (0.01 t...

A new controlled release system of a mosquito larvicide, fenthion has been developed by the chemical modification of sodium carboxymethylcellulose into a hydrophobic gel of copper carboxymethylcellulose. Four formulations having a slab geometry were developed with two concentrations of the larvicide and two extents of cross-linking. The release pro...

Three controlled release formulations of the insect repellent DEPA (N, N-Diethyl phenylacetamide), Depa-A, Depa-B and Depa-C have been developed and tested on human subjects against Aedes aegypti adult mosquitoes for repellency and the results were compared to those of a solution of DEPA (Depa-0). The increase in the protection time of the formulat...

Out of the 30 substituted diphenyl ethers synthesized and tested for insect growth regulating (IGR) activity against mosquitoes, three compounds viz., DPE-16, 19 and 28 showed promising IGR activity. While DPE-16 and 19 were found to be effective against all three vector species tested viz., Culex quinquefasciatus, Aedes aegypti and Anopheles steph...

The role of permethrin impregnated bednets at the application rate of 0.5 g (ai)/m2 in reducing A. culicifacies population in a tribal village of Orissa, highly endemic for Plasmodium falciparum was studied. The per man-hour density was significantly reduced in the Kenduguda village for about three months where impregnated bednets were supplied to...

The efficacy of K-Othrine® (Decamethrin)-a synthetic pyrethroid as larvicide and adulticide was tested against Culex quinquefasciatus, Anopheles stephensi and Aedes aegypti. This residual effect of the insecticide on different surfaces viz., cement, mud and thatched, was also determined at dosages of 50 and 100 mg (ai)m2.

Petroleum ether extracts of seven indigenous plants abundant in and around Pondicherry (south India) viz., Ocimum basilicum, O. sanctum, Azadirachta indica, Lantana camara, Vitex negundo, Cleome viscosa and Bulmea sp. were studied for their larvicidal action on the field collected fourth instar larvae of filaria mosquito, Cudex basilicum and Vitex...

Aus dem Ethinyl- carbinol (I) entsteht das Vinyl-derivat (II), das zu einem Acetylderivat (IIIa) hydratisiert und weiter zu (IIIb) acetyliert wird.

The ketol and its acetate when refluxed in methanolic potassium hydroxide (5%) were found to rearrange to 4-methyl-8-acetyl-5,6,7,8-tetrahydro-1-naphthol . The epimeric acetate also behaved likewise. A mechanism is suggested for the rearrangement.

Dihydroresorcin (I) liefert nach Methylierung und Robinson-Anellierung das Dioxooctahydronaphthalin (III), das in das Vinylethinylcarbinol (IV) übergeführt wird.