Studies in A Synthesis and Antimircobial Activities Of 2-(3,4,5-Trimethoxyphenyl)Thiocarbamide/Substituted thiocarbamid

Introduction

Recently in this laboratory the synthetic applications of cynoguanidine and 1,3-diformamidothiocarbamide had been briefly explored¹. As evident from structure of 2-(3,4,5-trimethoxyphenyl)ethamine processes amino and methoxy  reactive sides for various reactions. As a wider programmee of this laboratory in the synthesis of nitrogen, sulphur and nitrogen and sulphur containing heteroacycles and heterocycles the interactions of cynoguanidine with various thiourea and isothiocynates had been investigated in sufficient details ^2-8_.  Some of these compounds showed remarkable pharmaceutical and biological activities^9-12.

An exhaustive literature survey showed that thiocarbamido^3-6 containing drugs play an important role in pharmaceutical, medicinal and drug chemistry having remarkable pharmaceutical, medicinal and biochemical applications. By considering all these facts, interactions of  with  various thiourea in isopropanol medium were investigate to isolate yet new series of  2-(3,4,5-trimethoxyphenyl)thiocarbamide/substitutedthiocarbamids and antimicrobial activities were studied.

Experimental

The melting points of the all synthesized compounds were recorded using hot Paraffin bath. The carbon and hydrogen analysis were carried out on Carlo-Ebra 1106 analyzer. Nitrogen estimation was carried out on Colman-N-analyzer-29. IR spectra were recorded on Perkin Elmer Spectrometer in range 4000-400 cm^-1 in KBr pellets. PMR spectra were recorded on Brucker Ac 300 F Spectrometer with TMS as internal standard using CDCl₃ and DMSO–d₆ as solvent. The purity of compound was checked on silica Gel-G Pellets by TLC with layer thickness of 0.3 mm. All chemicals used were of AR-grade.

2-(3,4,5-trimethoxyphenyl)thiocarbamide:-

A mixture of 2-(3,4,5-trimethoxyphenyl)ethamine (1) (0.1M), thiourea (0.1) (2a) and isopropanol (40ml) was refluxed on boiling water bath for 5 hrs. During boiling suspended 2-(3,4,5-trimethoxyphenyl)ethamine  and thiourea went into the solution and the new product was found to be gradually separated out .Which on basification with dilute ammonium hydroxide afforded crystals. It was filtered in hot condition and crystallized with aqueous ethanol to obtain (3a), yield 87.7%, melting point 158⁰ C.

Properties:- It is white , crystalline solid  having melting point 158⁰C. It gave positive test for nitrogen and sulphur. Desulphurised with alkaline plumbite solution. It formed picrate, melting point 148 ⁰ C. Elemental analysis:- C [(found 52.21%) calculated 53.34], H [(found 7.26%) calculated  6.66% ], N [(found  09.74%) calculated 10.36%], S[(found 11.37%) calculated 11.85%]. IR Spectra:-The IR spectra was carried out in KBr pellets and The important absorption can be correlated as (cm^-1) 3251.2 (N-H stretching), 3051.5 [C-H(Ar)] stretching 1534.3 (C-N stretching ), 1428.4 (=C=NH imino), 1199.7(C-N stretching), 892.8 (N=C=S). PMR Spectra:-The spectrum was carried out in CDCl₃ and DMSO-d₆ .This spectrum distinctly displayed the signals due to Ar-H, protons at δ7.9525-7.9543 ppm. NH protons at δ 5.0417-5.0483 ppm, Ar-methoxy protons at δ 4.2911-4.4564 ppm. –CH₂ protons at 3.3386-3.8638 ppm.

Similarly other 2-(3,4,5-trimethoxyphenyl)substitutedthiocarbamides were synthesized by above mentioned method and are summarized in Table No.1

Table No.1

Sr.No.	Expt.No.	2-(3,4,5-trimethoxyphenyl)substitutedthiocarbamide	Yield%	m.p. 0C
3b	2	…………………… -Phenyl…………	78	216
3c	3	………………..Methyl …………………	68	178
3d	4	……………….-Ethyl………………………	82	157
3e	5	………………..Allyl……………………	69	164

Antimicrobial and Antifungal Activities

The antimicrobial and antifungal activities¹³ of all these  compounds were screened  by using cup-plate agar diffusion method in DMF, using standard Co-Trimazin 25 µg/ml  against gram positive and gram negative bacteria such as  E. coli, S. typhi, S. abony, P. aeruginosa,  and         B. subtilis. While all compounds were also screened for their antifungal activities by using standard Greseofulvin (10µg/ml) against A. niger and C. albicans.

Cup-plate method

A medium used during the experiment was HI-Media (India make) having composition of

Pepton – 5gm/lit., NaCl -5gm/lit, Yeast extract -1.5gm/lit, Agar powder -20gm/lit,  p^H – 7.4 ± 0.1

The medium for antibacterial and antifungal activities were prepared [N-agar for bacterial and Sabourands dextrose agar for fungi] by dissolving 26 gms of ingredients in one liter of distilled water and sterilized in autoclave at 121 ⁰C at 15 Ibs/inch pressure in an autoclave for 154 minutes. Then microbes were inoculated with requisite quantity to the medium at temperature 40-50⁰ C and immediately poured the inoculate medium in to sterilized petridishes to give a depth of 3-4 mm of uniform thickness. After solidification the well or holes were prepared by well borer. The dimethylformamide solution of the compound was added in sufficient amount to fill the well. Then it was kept at room temperature for 4 h, as a pre-incubation and then plates of bacteria were inoculated for 18-24 hrs, at 36-38⁰C   and all plates fungi were inoculated 48 hrs at 20-25 ⁰C. After the period of inoculation, zones of inhibition were recorded around the wells. The results are cited in Table No.2

Comp. No	S.typhi (mm)	E.coli(mm)	S. abony (mm)	P.aeruginosa(mm)	B. subtilis(mm)	A. niger (mm)	C. albicans (mm)
3a	1.1	1.1	1.1	0.9	0.5	—	—
3b	1.7	1.8	1.9	1.2	1.1	0.2	—
3c	1.5	1.2	1.2	0.8	0.7	—	—
3d	1.3	0.8	0.7	0.7	0.5	0.3	—
3e	1.1	1.3	1.4	1.2	0.7	—	—

All the seven organisms studied are human pathogens from the results it is clear that all the synthesized compounds showed remarkable and considerable antimicrobial activities. These thiocarbamides showed highly activity against E. coli, S. typhi, S. abony, P. aeruginosa, B. subtilis, While less active against A. niger and C. albicans. Hence study of these compounds is required in biochemical and medicinal directions. From the above data it is concluded that this compounds showed remarkable antibacterial activity that antifungal activity. S. typhi causes typhoid while E. coli causes diarrhea and S. abony causes pus formation. It is observed from literature survey of medicinal sciences that in the last two decades the patients of typhoid and diarrhea throughout the world are common. Lower drugs of typhoid are now totally rejected and higher drugs are now given to the patients. As newly synthesized thiocarbamides showed remarkable and considerable activities so these compounds can be used as alternative for the treatment of diseases caused by the above mentioned pathogens only if they do not have toxic and other side effects after the details study. The potency of the drug is increased due to substitution of thiocarbamido moiety on the previous drug.

Acknowledgment

Author is very much thankful to Dr D.T.Tayade, Associate Professor in Chemistry Govt. Institute of Science and Humanity Amravati for valuable help during this work.

References

1. Tayade D. T, Ph.D Thesis Amravati University, Amravati (1996).
2. Rudnitskaya O. V, Kultyshkina E. K, Linko I. V, Sergienko V. S and Aleksandrov C. G, Russian J of Co- ordination Chem-36, 137-142, (2010).
3. Tayade D.T., Bhagwatkar R.A, Panpalia R.C., International Journal of Chemistry  Canada .2 (2), 41-43,( 2010).
4. Tayade D.T., Bhagwatkar R.A, Panpalia R.C., International Journal of Chemistry Canada. 2 (2), 41-43,(2010).
5. Bhagwatkar R.A , Tayade D. T. , Orbital Elec. J. Chem., Campo Grande Brazil, 3(1), 53-56, (2011).
6. Tayade D.T.Pund .D.A., Bhagwatkar R.A, Rathod D.B. Bhagwatkar N.A., International Journal of Chemistry Canada . 3 (1), 36-41, (2011).
7. Tayade D.T., Raghuwanshi M. R., Bhagwatkar R.A., International Journal of Chemistry Canada . 3 (2), 74-78, (2011).
8. Shrivastava P.K., “Bases related with thiourea”, Ph.D. Thesis , B.H.U.(1964).
9. Dover L.G, Alahari A., Gratraud P, Gomes J. M, Bhowruth. V, Reynolds R. C, Besra G. S and Kremer Ln, Antimicrobial Agents and Chemotherapy 519(3), 1055-1063 (2007).
10. Paranjpe M.G, J Indian Chem Soc 42, 45 (1966).
11.  Joshua.C.P, Ph.D., Thesis, B.H.U (1962).
12. Deohate P.P., Berad B.N., Indian J.Chem.44B, 638-642 (2005).
13. Raghuwanshi M.R. Ph.D Thesis S.G.B. Amravati University, Amravati (2009).

---

This work is licensed under a Creative Commons Attribution 4.0 International License.