Green colour signals to proceed and green chemistry signals to sustain. In present study a novel thiadiazole derivative of Guar gum is synthesized by a sustainable greener method i.e. microwave assisted synthesis. Thiadiazole constitutes a class of heterocyclic compounds with good pharmacological profile. Guar gum is used as an emulsifier, thickener and stabilizer in various food and cosmetic industries. The newly synthesized derivative was characterized by IR, H1 NMR and mass spectrometry analysis. Antimicrobial activity was also studied.