Characterization and Biological Activity of Some New Derivatives Derived from Sulfamethoxazole Compound

A new series of Sulfamethoxazole derivatives was prepared and examined for antifibrinolytic and antimicrobial activities. Sulfamethoxazole derivatives bear heterocyclic moieties such as 1,3,4-thiadiazine {3}, pyrazolidine-3,5-diol {4} 6-hydroxy-1,3,4-thiadiazinane-2-thione {5} and [(3-methyl-5-oxo-4,5dihydro-1H-pyrazol-4-yl)diazenyl] {8}. Their structures were elucidated by spectral methods (FT-IR, H 1 NMR). Physical properties are also determined for all compound derivatives. Recently prepared compounds were tested for their antimicrobial activity in the laboratory. Each screened compound showed good tendency to moderate antimicrobial activity.


Introduction:
Sulfamethoxazole (SMZ or SMX) IUPAC is chemically labeled as 4-Amino -N-(5methylisoxazol-3-yl) -benzenesulfonamide is a wide board antibiotic. It was approved in the United States in 1961. At present, it is mostly used in combination with trimethoprim (abbreviated SMX-TMP). It is also referred to as sulfamethalazole, sulfisomezole, and sulfamethazole. It is used for many bacterial diseases and is effective against both germs positive and negative. (1) In the recent years, a great number of sulfamethoxazole derivatives were synthesized, characterized, tested and used for the treatment of many infections. (2)A large number of Sulfamethoxazole derivatives are currently designed based on heterocyclic moieties, they are widely used in clinical medicine exhibits as pharmacological agents with a wide range of biological procedures such as anti-cancer treatment, (3)antiviral agents, (4)anti-fungal, (5)herbicidal activities, (6) antimycobacterial (7) and antitubercular uses (8). In the light of the facts and due to the huge development in antimicrobial activities of sulfamethoxazole derivatives, a series of heterocyclic rings such as 1,3,4-thiadiazine, pyrazolidine-3,5-diol, 6-hydroxy-1,3,4thiadiazinane-2-thione compounds are designed and synthesized.

Materials and Methodologies:
All the chemicals used in this work were of highest purity available and supplied without further purification in Layer Chromatography (TLC) was checked by pro-coated sheets with silica -gel as immobile phase Appropriate solvent(ethanol) as mobile phase (Melting points) was specified by Stuart melting point SMP10 Spectr (FT-IR) were via KBr disk on SHIMADZU FT-IR-8300 spectrophotometer in Ibn Sina Company and College of Sciences for Women in University of Baghdad. ¹H-NMR measurements were achieved from Moscow University of Russia, operated at 500MH Z in DMSO-d 6 .

Synthesis methods 4-[(3-methyl-5-oxo-4,5dihydro-1H-pyrazol-4-yl)diazenyl]-N-(5methylisoxazol-3-yl) benzene sulfonamide compound (8) preparation. (16)
To (7) hydrazine hydrate99% (3.6g, 1mmol.) gently added. The reaction mixture was reactivated for (3 hrs.) and then cooled to room temperature. The solid precipitate is formed washed, dried, and crystalized from ethanol. compound as listed in Table ( FTIR spectrum for compound (1) showed new band at (3263 cm -1 ) were assigned to the v(N-H)sym. stretching symmetry. Besides the appearances of v(C=O) stretching band attributable to amide group at (1693 cm -1 ) and stretching band at (2881cm -1 ) back to v(CH 2 ) and at (1600 cm -1 ) for (C=N) isoxazole are best proof for the structure give to intended compound as listed in Table (2) FTIR spectrum of hydrazine carboxamide showed remarkable stretching bands in (3321 cm -1 ) and (3267 cm -1 ) which were assigned to the ν (-NHNH 2 ) group frequency stretch proved the formation of compound (2). On the other hand, disappearance of ν(-NHNH 2 ) (CH 2 ) and (C=O) group stretching frequency for thiadiazine ring is considered a good proof of formation of compound (3) FTIR spectrum for pyrazolidine-3,5-diol compound (4) gives starching bands for v(O-H) at (3365cm -1 ) and v(CH 2 ) at (2835cm -1 ). While pyrazolone compound (5)   Other sulfamethoxazole derivatives attached with pyrazolidine-3,5-diol rings, 6hydroxy-1,3,4-thiadiazinane-2-thione moieties compounds (4) and (5) Table (3) .It displayed signals attributed to sulfamethoxazole attached to thiadiazine moiety compound (3), methyl group attached to isoxazole ring, for 2-CH-groups of thiadiazine ring, (CH) isoxazole ring, fourteen aromatic ring protons, one proton of secondary amine (NH), two protons of amines attached to phenyl group, two proton for amine group of thiadiazine respectively as shown in Table (3) 1 H-NMR spectrum of pyrazolidine-3,5diol compound (4) displayed the basic characteristic signals(1.19) due to three protons of the methyl group connected to isoxazole ring, four protons of -CH-pyrazolidine rings, four protons of methylene CO-CH 2 -N, two protons of NH pyrazolidine, four protons metheylen pyrazolidine rings, one proton of CH isoxazole ring, four protns of hydroxyl groups -OH, four protons of aromatic ring and one protone of Ph-NH-CO respectively as shown in Table-3. 1 H-NMR spectrum of pyrazolone compound (5) detected significant characteristics of chemical shifts and showed suggested signals, the attribution of the( CH 3) linked to isoxazole ring, four protons for methylene groups of thiadiazinane rings, two protons of hydroxyl groups -OH, one proton of CH isoxazole, four aromatic ring protons, four proton of NH thiadiazinane, and one proton of Ph-NH-C thiadiazinane ring respectively as shown in the Table 3.       Diazotization reaction of start sulfamethoxazole with sodium nitrite with hydrochloric acid yield the diazonium chloride derivative of sulfamethoxazole compound (6). Diazonium salt (4) then it was treated with ethyl acetoacetate in the presence of sodium hydroxide to give derivative (7). Final product of rings attached with sulfamethoxazole compound (8) were obtained in good yield from condensation of compound (7) with hydrazine hydrate. The synthetic routes for preparation of mentioned compounds (6)(7)(8) are shown in Scheme (3).

The Antimicrobial Activity:
The inhibition zone of the newly synthesized sulfamethoxazole derivatives (1)(2)(3)(4)(5) were observed and measured. The biological activates of some prepared compounds (C 1 , C 2 , C 3 , C 4 , C 5 , C 6 ) were tested against bacterial strains and fungi. Escherichia coli, staphylococcus aureus and candida alb(1icans were well diffused using ager method. The results of this study are summarized in Table 4 and shown in Figs 1, 2 and 3 respectively.   Table 4 shows anti-bacterial and antifungal results which were interpreted in terms of the diameter of inhibition zone for antibacterial activity showed medium biological effect against Staphylococcus aureus and against E.coli, although it showed high effect forward Candida albicans.

Conclusion:
This paper reports the changes in various physical properties associated with the derivatization of sulfamethoxazole. The properties studied include by FTIR, and 1 H-NMR spectroscopies that derivatization substantially changed the pharmaceutical properties antibacterial activities of these compounds against Gram-positive bacteria (Staphylococcus aureus,), Gram-negative bacteria (Escherichia coli,) and yeast-like fungi (Candida albicans)