Isolation, Structural Characterization, and Validation of a New Compound Present in Non‐Carbonyl Curcuma longa (NCCL): A Potential Lead for Stroke

The hexane soluble extract of Curcuma longa (Turmeric) [herbal medicament (HM)] developed by Central Drug Research Institute, India, as a new antistroke agent. It contains carbonyl as well as non‐carbonyl compounds. To see the activity of non‐carbonyl compounds, HM was reacted with semicarbazide hydrochloride to remove the carbonyl compounds. This chemically modified fraction [non‐carbonyl Curcuma longa (NCCL)] of HM was found to be active at lower dose than HM against endothelial mediated inflammation in myocardial ischemia/reperfusion induced rats. It reduced significantly the serum CK‐MB levels, inflammatory cytokine mediators (TNF‐α, IL‐6, IFN‐γ), plasma endothelial microparticle level and also found useful in improving the endothelial functionality. It was also found active in anti‐inflammatory and cytotoxic activity for sepsis and leukemia. To find out the compounds that are responsible for its enhanced activity in comparison of HM, we have isolated two major peaks present in the high‐performance liquid chromatography (HPLC) fingerprint of NCCL and their structures were characterized. Based on the characterization, we found that these compounds are not the non‐carbonyl compounds present in HM but the new cyclic structures formed by the reaction of ar‐turmerone, α‐turmerone, and β‐turmerone with semicarbazide hydrochloride used in the reaction. This hypothesis was validated by isolation of ar‐turmerone, α‐turmerone, and β‐turmerone from HM and reacting them with semicarbazide hydrochloride using the same reaction conditions of NCCL formation. The same mass spectral data and same retention time (RT) value in high‐performance liquid chromatography analysis further confirms our hypothesis.