Bis Tributyltin Oxide Research Articles

Synthesis, characterization, DFT and docking studies of tributyltin(IV) complex of 2-{4-hydroxy-3-[(2-carboxyphenylimino)methyl]phenylazo} benzoic acid

A tributyltin(IV) complex was prepared by reacting bis-tributyltin(IV) oxide with 2-{4-hydroxy-3-[(2-carboxyphenylimino)methyl]phenylazo}benzoic acid in a 1:1 metal-ligand ratio. The complex was characterized by elemental analysis, UV-Vis, IR,1H and 119Sn NMR spectroscopy and mass spectrometry techniques. The 119Sn NMR study of the complex indicated the presence of two tin centers in a similar chemical environment and the complex exhibited a five-coordinate trigonal bipyramidal geometry in the solution phase. The molecular ion peak in the EI-MS spectrum of the complex revealed its molar mass. The optimized geometry of the complex was predicted by a DFT calculation. The in vitro antifungal activity of the complex was studied against four fungal species with respect to the standard drug Amphotericin-B. A molecular docking study was also carried out to understand the mode of interaction of the complex with the active side of the enzyme present in fungal species.

Synthesis, characterization, crystal structures and anti-diabetic activity of organotin (IV) complexes with 2-(4-hydroxynaphthylazo)-benzoic acid

Three new organotin(IV) complexes 1–3 were synthesized by the reaction of 2-(4-hydroxynaphthylazo)-benzoic acid with bis-tributyltin(IV) oxide (1), dibutyltin(IV) oxide (3) or trimethyltin(IV) chloride (2), respectively. The complete characterization of the complexes was accomplished by elemental analysis, IR and multinuclear [1H- and 13C- and 119Sn-] NMR spectroscopy. The crystal structures of all the complexes were elucidated with the help of X-ray single crystal diffraction analysis. The geometry around tin atoms in 1 and 2 was trigonal bipyramidal geometry where the equatorial plane was occupied by the three alkyl groups (Bu or Me) and the axial positions in 1 were being occupied by carboxylate and phenoxide oxygen atoms giving rise to a polymeric structure. In 2, a hydroxy oxygen atom bridges two tin atoms occupying axial position while the other axial positions in each tin atom were being occupied by a carboxylate oxygen atom or oxygen atom of a water molecule respectively thereby completing trigonal bipyramidal geometry. The structure of 3 was a di-nuclear complex with six-coordinate distorted skew trapezoidal and seven-coordinate pentagonal bipyramidal geometry around the tin atoms, respectively. In the dinuclear structure, one of the tin atoms is coordinated by a terminal azo-ligand while the other tin atom is coordinated by two terminal azo-ligands. In addition to this, another azo-carboxylate ligand bridges the two atoms in the dinuclear structure. The NMR study showed that in the solution the complexes 1 and 2 adopted four-coordinate geometry, while in 3 there is five-coordinate structure. Complexes 1 and 3 were screened for their antidiabetic activities against α-glucosidase enzyme and results of the assay found that compound 3 exhibited significant inhibition activity.

Hitting a Soft Drug with a Hard Nucleophile: Preparation of Esmolol's Metabolite by Treatment with Bis(tributyltin) Oxide

A facile method for the production of esmolol's metabolite in high purity is described. Bis(tributyltin) oxide is used to disrupt esmolol's ester linkage, and hydrolysis is completed by addition of water, which also allows the inorganic side products to be conveniently extracted into ether. Evaporation of the aqueous phase and trituration with ethyl acetate provides the carboxylic acid–amine internal salt as a white, free-flowing powder.

Bioproduction of antimicrobial compounds by using marine filamentous cyanobacterium cultivation

The synthesis of bioactive compounds with antimicrobial activity, excreted by marine cyanobacteria, strongly depends on their growth conditions. Due to the wide variety of biomolecules which could show properties as growth inhibitors and their low concentrations within the culture medium, the activity of their crude extracts also seems to be related to the extraction method used. Using the marine filamentous cyanobacterium Geitlerinema strain Flo1, we demonstrate a systematic approach for identifying optimal culture conditions to obtain culture media extracts with antimicrobial activity. The changes in the culture conditions, such as the addition of NaBr to the medium, cell immobilisation in vegetable sponge pieces, or temperature, effected the production of these bioactive compounds. The crude extract, containing middle polar molecules, obtained by extraction with Amberlite XAD-1180 had a higher antifouling activity upon a number of bacteria and fungi than the extract obtained by extraction with Amberlite XAD-16. The lowest inhibitory concentration obtained upon Rhodosporidium sphaerocarpum was still ten times higher than that of bis(tributyltin)oxide, but compared to zinc pyrithione, it was two times more active.

ChemInform Abstract: Dehydrochlorination of Hydroximic Acid Chlorides by the Use of Organotin Compounds: An Application for Synthesis of Isoxazolines and Isoxazoles.

The reactions of hydroximic acid chlorides and organotin compounds such as bis(tributyltin) oxide or tetraphenyltin, whereby nitrile oxides are generated effectively, are applied to the preparations of isoxazolines and isoxazoles via[3 + 2] dipolar cycloaddition.

Effect of bis(tributyltin) oxide on reproduction and population growth rate of calanoid copepod Schmackeria poplesia

A full life-cycle toxicity test, combined with histology, on calanoid copepod Schmackeria poplesia was used to study the effect of bis(tributyltin) oxide (TBTO). The results indicate no sex-specific differences in TBTO toxicity. Long-term mortalities of the copepods exposed to concentrations higher than 20 ng TBTO L−1 were significantly elevated compared with that of control, and larval development was inhibited when they were exposed to 40 and 60 ng TBTO L−1. The percentages of ovigerous females were reduced compared with the control (P<0.01) after 24 days exposure to concentrations higher than 10 ng TBTO L−1. Histological examinations suggest that exposure to TBTO might block the posterior end of the diverticula and inhibits the production of egg sacs. A modified Euler-Lotka equation was used to calculate a population-level endpoint, the intrinsic rate of natural increase (r m), from individual life-table endpoints, i.e. mortality rate, time of release of first brood, sex ratio, the fraction of ovigerous females among all females as well as the number of nauplii per ovigerous female. Apart from the highest TBTO concentration (60 ng L−1), where all females aborted their egg sacs, 20 ng TBTO L−1 was the only concentration that significantly decreased r m compared with that of control (an effect associated with decreased sex ratio). The results show that the S. poplesia is affected by prolonged exposure to low concentrations of TBTO. The full life-cycle toxicity test combined with histology experiments provides more integral understanding of the toxicity of endocrine disrupters.

Synthesis and Characterization of Polymeric Derivatives Containing Grafted Triorganotin Cinnamates with Electrochemical Chloride Response

Poly[(p-vinyl) cinnamic acid] and the corresponding copolymers with styrene were prepared. Subsequent functionalization with bis(tributyltin) oxide or bis(triphenyltin) oxide afforded the corresponding homo- and copolymeric tributyltin or triphenyltin cinnamates, respectively. The coordination at tin in solution and in the solid state was investigated by 117Sn solution and solid-state NMR. The polymeric triphenyltin carboxylates exhibit four-coordination at tin, in solution as well as in the solid state. While this also holds for the tributyltin analogues in solution, they exhibit mixed four- and five-coordination in the solid state, the relative amount of five-coordination increasing with increasing tin functionalization. The difference between the tributyl- and triphenyltin compounds is interpreted in terms of both steric factors, and rigidity of the cinnamate side chain of the polymers. The electrochemical anionic response of the polymeric tributyltin carboxylates to chloride has been assessed by potentiometric measurements with liquid membranes. The response is weaker for the polymers than for analogous non-polymeric reference compounds, probably as a consequence of the hydrophobic barrier created by the polystyrene backbone. No evidence for carrier leaching by hydrolysis of the tin moiety could be found.

REGIOSELECTIVE BENZYLATION OF PENTITOLS, TETRITOLS, AND SOME HEXITOLS VIA THEIR STANNYL ETHER DERIVATIVES: VERSATILE SYNTHESIS OF MONOBENZYLALDITOLS

The xylitol, ribitol and D-arabinitol were transformed into their tributylstannyl ether derivatives by reaction with bis-tributyltin oxide [(nBu3Sn)2O I] and azeotropic removal of water. Subsequent benzyl etherification, using BnBr with solvent or under free solvent conditions, led regioselectively to primary mono-O-benzylalditol derivatives in satisfactory yields for a direct regioselective synthesis (∼ 52%). This etherification when applied to tetritols and some hexitols exhibits similar behaviour. With pentitols, an analogous study carried out with the n-dibutyltin oxide [nBu2SnO (II)] as the activating reagent showed contrasting results as regards regioselectivity.

Sweat gland toxicity induced by bis (tributyltin) oxide: an ultrastructural and X-ray microanalysis study.

Acute toxicity of bis (tributyltin) oxide in the sweat glands in the rat footpad was investigated by electron microscopy and an energy-dispersive X-ray microanalyzer. Male Wistar rats received an intramuscular injection of 0.5 ml/kg bis (tributyltin) oxide. After 6-8 h, swelling of mitochondria appeared in the secretory cells of the sweat glands. After 12 h, the secretory cells began to show intracytoplasmic edema. After 16-20 h, secretory cells in some sweat glands showed marked hydropic degeneration with swollen cytoplasm. Using X-ray microanalysis, tin peaks were preferentially obtained from the swollen mitochondria of the affected secretory cells. Mitochondria dysfunction due to the toxic effects of bis (tributyltin) oxide induced changes in the secretory cells of rat sweat glands. After 24-48 h, the secretory portion of the sweat glands contained three types of cells: degenerating dark cells, regenerating cells carrying injured mitochondria, and light cells which were morphologically very similar to the cells in the transitional portion of the sweat gland. These light cells appeared to differentiate into active secretory cells after settling down in the secretory portion. Based on these observations, we concluded that the cells in the transitional portion could play an important role at least as reserve cells against secretory cell toxicity. In association with the regenerating process of the damaged secretory portions, increased mitotic activities were seen in different areas of all the dermal sweat ducts. The above-mentioned morphological observations for cell damage and subsequent regeneration and renewal ofsecretory cells in sweat gland intoxication have not been reported so far.

REGIO- AND STEREOSELECTIVE ALCOHOLYSIS OF (R)-STYRENE OXIDE WITH BIS-TRIBUTYLTIN OXIDE AND BIS-CHLORODIBUTIYLTIN OXIDE

Article REGIO- AND STEREOSELECTIVE ALCOHOLYSIS OF (R)-STYRENE OXIDE WITH BIS-TRIBUTYLTIN OXIDE AND BIS-CHLORODIBUTIYLTIN OXIDE was published on October 1, 1998 in the journal Main Group Metal Chemistry (volume 21, issue 10).

Liquid-phase hydrogenation of car☐ylic acid on supported bimetallic Ru [sbnd]Sn-Alumina catalysts

Heterogeneous Ru Sn catalysts are effective for the liquid-phase hydrogenation of C O group in car☐ylic acids. Hydrogenation activity was affected by the kind of tin compounds used for the preparation of the Ru Sn catalyst. Bis-tributyl tin oxide ((Bu 3Sn) 2O), K 2SnO 3 and Na 2SnO 3 were found to be the appropriate materials for the hydrogenation of C O group over the Ru Sn catalysts. The C O hydrogenation activity for the hydrogenation of car☐ylic acids increased with the increasing amount of Sn added whereas, the C C hydrogenation activity decreased. Effect of activation temperature was also studied. The C O hydrogenation activity was increased by calcinating the catalyst precursor, Sn/alumina, before impregnation with Ru solution. The calcination of the Sn/alumina at 973 K was quite effective for the hydrogenation of car☐ylic acids over the resultant Ru Sn/alumina catalysts. The Ru Sn/alumina catalysts reduced at 723 K were also effective for the hydrogenation of car☐ylic acids. We have also studied the hydrogenation in a continuously flowing system. The Ru Sn/alumina catalysts showed high and stable activity under mild conditions in the flowing system.

Selective deprotection of phenacyl, benzyl and methyl esters of N-protected amino acids and dipeptides and N-protected amino acids benzyl ester linked to resins with bis(tributyltin) oxide

Phenacyl, methyl and benzyl esters of variousN-α-Boc, N-α-Cbz or N,N-dimethylamino protected amino acids and dipeptides, as well as esters of N-α-protected amino acids linked to Wang and Pam resins have been efficiently and chemoselectively cleaved by bis(tributyltin) oxide in aprotic solvents to give the corresponding carboxylic acids in good yields. Moreover, the absence of racemization during the deprotection has been demonstrated. A limitation of the method is the instability of the N-Iµ-Fmoc group in the amino acid esters 8 and 10, N-α-Fmoc-L-alanine linked to Wang resin 23 and the Cbz protecting groups in N-α-Boc-N-Iµ-Cbz-L-lysine benzyl and methyl esters (5 and 7), respectively, and N-α-Cbz-L-alanyl-L-alanine methyl ester 19. In the case of N-α-protected dipeptides, there was no evidence of free amino acid which indicates that the peptide bond is unaffected.

Mild deprotection of steroid esters by Bis(tributyltin)oxide

Bis(tributyltin)oxide (BBTO) has been utilized for the first time for the deprotection of steroid esters. The best results were obtained for 3β-esters, in particular the selective hydrolysis of the 3β-acetyl group in 3β,6α-diacetoxy-5α-pregnan-20-one to give 6α-acetoxy-3β-hydroxy-5α-pregnan-20-one.

ChemInform Abstract: Chemoselective Coupling of α‐Bromo Aldehydes with a Tin Enolate Derived from the Ring Opening of Diketene by Bis(tributyltin) Oxide.

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Influence of bis(tributyltin) oxide on aminyl radical cyclizations

Cyclization of N-butyl-N-4-pentenylaminyl radical 3 in benzene at 80 °C is enhanced significantly by the presence of bis(tributyltin) oxide.

Tolerance of Marine Bacteria for Organotin Compounds (OTCs) in Areas with or without OTC Contamination

Bacterial tolerance to bis-tributyltin oxide (TBTO) and triphenyltin chloride (TPT) was compared at different contaminated areas by the agar plate method. The TBT concentration at which colony forming units (CFU) began to decrease (inhibitory concentration, IC) was almost the same within the range of 2 to 40 μg Sn/l of TBTO for all samples but one. The proportions of TBTO-tolerant bacteria were also not related to the ambient level of contamination. The Tolerance of bacteria in sediment samples was higher than that in water samples from each station, but was not proportional to the level of contamination. The numbers of TPT-tolerant bacteria did not reflect the numbers of TBTO-tolerant bacteria. These findings demonstrate that the distributions of TBT- and TPT-tolerant bacteria were independent to of the level of TBT contamination.

Biofouling and its Possible Modes of Control at Fish Farms in Penang, Malaysia

Biofouling by 13 selected organisms was monitored with regard to their settle• ment patterns and their suppression by three types of chemicals. Their settlement patterns over a period of 180 days within a depth range of 1.5 m can generally be divided into three types. The early settlers colonizedthe substrata within the first two months of submergence and disappeared towards the end of the experiment. The second type also reached a peak density sometime during the first or second month, but declined slightly at the end. The late settlers started to appear only on the second or third month and their numbers were mostly sustained till the end. However, the distribution of all the organisms except barnacles and tunicatea was random within the depth range studied. Biofouling was also significantly associated with the types of substrata. The three chemicals used. namely antifouling paint, formulated bis-tributyltin oxide and tannin extract effected various degrees of suppression on fouling. The effects of bis-tributyltin oxide was similar to that of antifouling paint in suppressing most of the 13 foulers studied except mobile molluscs. But the degree of suppression by the former was milder as measured by the mean weight of the foulers at 42.3 g against 20.1 g of the latter. Tannin extract was least effective and suppression was only restricted to a few groups such as sea anemones, serpulid polychaetes, bryozoans and sessile molluscs.

Novel method for generation of an organotin enolate by the cleavage of diketene with bis(tributyltin) oxide, and its Michael reactions

Generation of a novel type of organotin enolate has been accomplished by the regioselective ring cleavage of diketene with bis(tributyltin) oxide; the enolate afforded the first example of Michael addition in reactions using organotin(IV) enolates.

Inhibitory Activity of Organotin Compounds Against Colony Formation of Estuarine Bacteria.

The sensitivity of estuarine bacteria to organotin compounds (OTCs) was examined using the agar plate method by counting colony forming units (CFU) for estuarine water samples gathered at Aburatsubo and Kachidoki. Inhibition of bacterial colony formation occurred in a concentration range of 2 to 40μg Sn/l of bis-tributyltin oxide (TBTO) and triphenyltin chloride (TPT) regardless of media composition, inoculation method, or sample water. Similar numbers of TBTO- and TPT-resistant bacteria were counted by the MPN method at the inhibitory concentration range, indicating that the agar plate method was applicable to tests of the sensitivity of natural populations of estuarine bacteria to OTCs. The inhibitory activity of seven kinds of TBTO- and TPT-related compounds was compared. The results revealed that dialkyltins were most toxic, followed by trialkyltins, monoalkyltins, and tetraalkyltins. This order is unique for bacteria, and has not to date been reported for any other organisms.

The effect of bis-tributyltin oxide (TBTO) and copper on the growth of juvenile Sydney rock oysters Saccostrea commercialis (Iredale and Roughley) and Pacific oysters Crassostrea gigas Thunberg

The growth of juvenile (spat) (1.25–2.62 mg dry wt) Pacific oysters C. gigas and Sydney rock oysters S. commercialis was reduced by only 5 ng bis-tributyltin oxide (TBTO) l −1 seawater. The reduction in growth of the Pacific oysters was more severe than that of the Sydney rock oysters. When Sydney rock oyster spat were exposed to both copper and TBTO they suffered a greater reduction in growth than those exposed to only one toxicant. There was no significant interaction ( P > 0.05) between the two toxicants, but an additive effect instead. Copper accumulation in Sydney rock oyster spat increased significantly ( P < 0.05) 1.2-times in the presence of 20 ng TBTO l −1.