The effects of triorganotins on the 4th instar stage of Aedes aegypti larvae were evaluated. The most effective of the 15 triorganotins used in the study was tributyltin chloride with an LC 50 value of 0.57 AE 0.07 mg dm À3 . The low LC 50 values obtained indicated that this class of compounds is an effective larvicide against the larvae of this species of mosquito. The toxicity of the compounds was found to be primarily dependent on the R group attached to the tin atom. The order of activity for the triorganotins tested was Bu b Ph b Cy b Me. However, a limited order, based on two series of the compounds tested, was also observed for the anionic X group on the tin atom.

Fourteen triorganotin compounds were tested against the second to the fourth instar larval stages of Anopheles stephensi (An. stephensi), a vector for human malaria. In general, the tricyclohexyltin compounds were the most effective. The LC50 values of the tricyclohexyltin compounds ranged from 0.010 μΜ for the chloride to 0.258 μΜ for the fluoride substituent against the second instar larval stage. Triphenyltin hydroxide and triphenyltin fluoride were the least effective larvicides. This was attributed to their polymeric nature. The efficacy of the triorganotins declined from the second instar to the fourth instar larval stages due to the formation of a thicker chitin covering. In general, the toxicity of the triorganotin compounds was found to be more dependent on the nature of organic ligand attached to the tin atom and not the anionic substituent.

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New organotin(1V) complexes of the types. R,SnL,, [where n = 3, m = 1, R = C,H,. CI-I, or C4119; n = 2, m = 2 . R = C,H, or C,H, and L = anion of N-acetylglycine (HL') and ~-acetyl-i)i.-tryptophan (HL')]. (R,Sn),L' [where R = C,H,, CH, or C,H, and L' = anion of N-acetyl-i--cysteine (H2L3)], R$nL'[where R = C,H, or C4H9 and L' = anion of (H2L3)] and Bu,(L)SnOSn(L)Bu, [where L = anion of (HL')] have been synthesized and characterized by elemental analyses, molar conductance. electronic. infrared, far-infrared, 'H NMR, I3C NMR and "' Sn Miissbauer spectral studies. Thermal studies of three complexes have been carried out in the temperature range 18-1O0O0 C using TG, DTG and DTA techniques. Possible structures of the complexes have also been proposed.

This paper reports the activity of four dibutyltin(IV)–N‐arylidene‐α‐amino acid complexes against the National Cancer Institute (NCI) panel of 60 cell lines. The results indicated that three of the organotin complexes (C17H25NO3Sn, C18H27NO3Sn and C20H31NO3Sn) exhibit their highest cytotoxic effect on the NCI‐522 (non‐small cell lung cancer) cell line. The fourth complex, C21H27NO3Sn, exhibits its highest cytotoxic activity on the cell line RXF‐631L (renal cancer). In general, a low to moderate cellular response was observed for all the organotin complexes, with at least one cell line in each subpanel of cells exhibiting a very low growth inhibition response to all the organotin complexes. The low‐responding cell lines included HOP‐62 (non‐small lung cancer), DLD‐1 (colon cancer), SF‐539 (CNS cancer), SK‐MEL‐5 (melanoma), IGROV‐1 (ovarian cancer) and RPMI‐8226 (leukemia). The results also indicated that the compounds did not exhibit any significant subpanel activity and suggested that the compounds were not active in all the cell lines contained in any subpanel. The low to moderate activity of these compounds across the cell lines was attributed to the presence of nitrogen‐bearing ligands which prevented the dissociation of the compound and the subsequent binding to DNA. © 1998 John Wiley & Sons, Ltd.

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The 14 triorganotin compounds that were screened against the brine shrimp, Artemia salina, were least effective against the first nauplii stage (24 h). This was attributed to the presence of a yolk membrane which reduced the contact between the triorganotin compounds and the organism. The data indicated that the species responsible for the toxicity is primarily the hydrated triorganotin cation. However, the anion X group may also play a minor role in the toxicity of these compounds. The observed order of activity for the triorganotins does not parallel their hydrophobicities, indicating that other factors must be involved in the toxicity mechanism.

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