10.22376/ijpbs.2019.10.1.p1-12 Volume 4 Issue 4 2013 (October - December) Sulfonamides/sul.fon.amides/ (sul-fon´ah-mÄ«d) are one of the organosulphur compounds containing the -SO lessThan sub greaterThan 2 lessThan /sub greaterThan NH lessThan sub greaterThan 2 lessThan /sub greaterThan and/or -SO lessThan sub greaterThan 2 lessThan /sub greaterThan NH- group(s). The sulfonamides or sulfa drugs competitively inhibit folic acid synthesis in micro-organisms and subsequently inhibit multiplication of bacteria but do not actively kill them. They have been used against most gram-positive and many gram-negative bacteria, some fungi, and certain protozoa. Medically important sulphonamides. AASTHA PAREEK, PRIYANKA RANI AND D. KISHORE Organosuphur compounds, Gram-negative bacteria, Gram-positive bacteria. 812-820