Himaja M et al / IJRAP 2010, 1 (1) 147-152 International Journal of Research in Ayurveda & Pharmacy, Volume 1, Issue 1, Sep-Oct 2010 147-152 Research Article Available online through www.ijrap.net SYNTHESIS AND ANTIMICROBIAL ACTIVITY OF DICHOTOMIN A ANALOGS Himaja Malipeddi a* , Malipeddi Venkataramana b , Sahoo Atish Kumar c , Anand Ranjitha a , Karigar Asif d *a VIT University, Vellore 632 014, India. b Aljabar Algharbi University, Zawia, Libya c NGSM Institute of Pharmaceutical Sciences, Paneer, Derlakatte, Mangalore, Karnataka, India d Maratha Mandal college of Pharmacy, Belgaum, Karnataka, India Received: 25-07-2010; Revised: 24-08-2010; Accepted: 16-09-2010 ABSTRACT A solution phase peptide synthesis was employed to synthesize Dichotomin A analogs. The N, O- dimethylation on Tyrosine and configurational change of L- to D- on Valine was made on Dichotomin A to derive the compounds 1) Cyclo-L-[Gly-Thr-Phe-Leu-(N-CH 3 , O-CH 3 ) Tyr-Val] and 2) Cyclo-L-[Gly-Thr- Phe-Leu-(N-CH 3 ,O-CH 3 )Tyr-D-Val]. The structure of these compounds was confirmed by IR, 1 H NMR, and FABMASS. The synthesized compounds were tested for their biological activities against bacterial and fungal organisms and were found to be active. Compound (2) carrying D-valine unit have shown more antimicrobial activity than the compound carrying L-valine unit. KEYWORDS: Dichotomin A, Cyclic hexapeptide, Solution Phase Synthesis, Antimicrobial activity *Author for correspondence Dr (Mrs).M.Himaja Professor, Pharmaceutical Chemistry Division, VIT University, Vellore-632014.Tamil Nadu, India. Mobile: +919944796228. Phone: 0416-2202330 e-mail:dr_himaja@yahoo.com