Design, synthesis and biological evaluation of aryl pyrimidine derivatives as potential leishmanicidal agents

A series of substituted aryl pyrimidine derivatives was synthesized and evaluated in vitro for their antileishmanial potential against intracellular amastigotes of Leishmania donovani using reporter gene luciferase assay. Among all, 8 compounds showed promising IC50 values ranging from 0.5 to 12.9 μM. Selectivity indices (S.I.) of all these compounds are far better than reference drugs, sodium stibogluconate (SSG) and miltefosine. On the basis of good S.I., compounds were further screened for their in vivo antileishmanial activity against L. donovani/hamster model. Compounds 2d, 4a and 4b have shown significant inhibition of parasitic multiplication that is 88.4%, 78.1% and 78.2%, respectively at a daily dose of 50 mg/kg × 5 days, when administered intraperitoneally. Compound 2d is most promising one, which may provide a new lead that could be exploited as a new antileishmanial agent.

Chemotherapy of leishmaniasis. Part IX: synthesis and bioevaluation of aryl substituted ketene dithioacetals as antileishmanial agents

A new series of aryl substituted ketene dithioacetals 6a-h was synthesized and evaluated for their in vitro and in vivo antileishmanial activity against Leishmania donovani. Two compounds exhibited significant in vitro activity against intracellular amastigotes of L. donovani with IC(50) values 3.56 and 5.12 μM and were found promising as compared with reference drug, miltefosine. On the basis of good Selectivity Indices (S.I.), they were further tested for their in vivo response against L. donovani/hamster model and showed significant inhibition of parasite multiplication 78% and 83%, respectively. These compounds were better than the existing antileishmanials in respect to IC(50) and SI values, but were less active than miltefosine in vivo.

Chemotherapy of leishmaniasis. Part VII: synthesis and bioevaluation of substituted terpenyl pyrimidines

Some novel 4-N-substituted terpenyl pyrimidines 5(a-d) and 7(a-g) have been synthesized using novel synthetic methods. The compounds were screened for in vivo antileishmanial screening. When compared to 4-thiomethoxy substituted pyrimidine 2 4-N-substituted terpenyl pyrimidines 5(a-d) and 7(a-g) were found inactive.

Chemotherapy of leishmaniasis. Part V: Synthesis and in vitro bioevaluation of novel pyridinone derivatives

Some novel 2-substituted pyridinone derivatives exemplified by 3 and 4 have been synthesized from 2-methyl-gamma-pyrone and screened towards in vitro antileishmanial activity profile. Some of the compounds such as 3a, 3b, 4i and 4j displayed good antileishmanial profile.

Chemotherapy of leishmaniasis Part VI: Synthesis and bioevaluation of some novel terpenyl S,N- and N,N-acetals

Some novel terpene based oxoketene S,N-acetals 2(a-g) and N,N-acetals 3(a-c) have been synthesized from oxoketene dithioacetal 1. The compounds were screened for their in vivo antileishmanial activity. Some of the compounds showed 50-70% inhibition in the hamster model.

Chemotherapy of leishmaniasis part III: synthesis and bioevaluation of novel aryl substituted terpenyl pyrimidines as antileishmanial agents

Some aryl substituted terpenyl pyrimidines 4 (a-p) have been synthesized using novel synthetic methods. The compounds were screened for in vitro antileishmanial activity against promastigotes. Compounds 4c, 4i and 4l showed IC(50) values as 35, 35 and 25 microg ml(-1).

Chemotherapy of leishmaniasis part II: synthesis and bioevaluation of substituted arylketene dithioacetals as antileishmanial agents

Some novel aryl substituted ketene dithioacetals have been synthesized using novel synthetic methods. The compounds were screened against Leishmania donovani in hamsters for their activity profile. Some of the compounds inhibited 50-65% parasite growth at 50 mg kg(-1) x 5 days.

Antileishmanial agents part-IV: synthesis and antileishmanial activity of novel terpenyl pyrimidines

Some novel N- and O-substituted terpenyl pyrimidines 4 (a-j) have been synthesized and screened for in vitro antileishmanial activity profile in promastigote model. Some of the compounds exhibited 100% inhibition at 10 microg ml(-1) concentration.

Synthesis and antileishmanial profile of some novel terpenyl pyrimidines

Some novel terpenyl pyrimidine derivatives 2(a-d) and 6(a-b) have been synthesised from alpha/beta-ionone keteneacetals 1 and 5. The terpenyl pyrimidine 2e has been synthesised from beta-ionone 3 in two steps in quantitative yield. The pyrimidine derivatives were screened for in-vivo antilesihmanial activity. The compounds 2d, 2e, 6a and 6b showed promising in-vivo antileishmanial activity.

Collision-induced dissociation of MCl(+) adducts (M = Mg, Mn, Zn, Co, Ni and Cu) and Cu(+) and Ag(+) adducts of dithioalkyl ketene acetals

Electrospray ionization mass spectra of equimolar solutions of dithioalkyl ketene acetals 1 and 2 and metal chlorides (MgCl(2), MnCl(2), ZnCl(2), CoCl(2), NiCl(2) and CuCl(2)) produced abundant ligated metal ion adducts [1 + MCl](+) and [2 + MCl](+). In addition, CuCl(2) also gave rise to Cu(+) adducts. The ligated metal ion adducts upon collision-induced dissociation (CID) showed characteristic fragmentation pathways reflecting the favoured site of coordination. The results show that MgCl(+) prefers oxygen over sulfur, whereas the reverse is true for ZnCl(+) adducts, exemplified by the preferred fragmentation of [1 + MgCl](+) as elimination of MgCl(OH), while that of [1 + ZnCl](+) is expulsion of ZnCl(SCH(3)). Co and Ni chloride adducts tend to give stable metal coordinated species. Cleavage of the dithiolane ring followed by elimination of C(2)H(4)S is the preferred pathway during the CID of [2 + MCl](+) adducts. The CuCl(+) adducts of 1 and 2 showed reduction of Cu((I)) to Cu((0)) resulting in the M(+)(*)ions of 1 and 2. Abstraction of *CH(3) resulting in elimination of CuCH(3) was observed during CID of Cu(+) adducts of 1 and 2. A comparative study of the corresponding Ag(+) adducts revealed a similar behaviour.