Background: Treating tuberculosis is a challenge due to the development of drug
resistance. Hence, it is imperative to develop novel leads having high potency and efficacy to curb
Methods: The present research work is focused on microwave-assisted synthesis of novel twenty-six
3-amino-N’-benzylidenepyrazine-2-carbohydrazide derivatives (3a-z), where, lyophilization
technique was used for isolation of the major intermediate, 3-aminopyrazin-2-carbohydrazide. All
synthesized compounds were subjected for anti-tubercular screening against Mycobacterium
tuberculosis H37Ra by using XTT Reduction Menadione Assay (XRMA) protocol.
Results: Out of 26 synthesized compounds, four N’-substitutedbenzaldehyde-3-amino-pyrazine-2-
carbohydrazide derivatives viz. 3i, 3j 3v and 3z showed significant activity against M. tuberculosis
H37Ra. The compounds 3i, 3j, 3v and 3z showed 99, 98, 92 and 87 % inhibition respectively as
compared to 94% inhibition shown by the standard drug rifampicin. The MIC and IC50 values were in
the range of 24.3-110 and 5.9-20.8 µg/ml respectively.
Conclusion: A classification model called Recursive Partitioning (RP) based on binary Quantitative
Structure-Activity Relationship (QSAR) was derived for the establishment of structure-activity
relationship (SAR). The predictions derived on the basis of RP model were found to be in agreement
with anti-tubercular screening data.