Open AccessInvestigating structural aspects to understand the putative/claimed non‐toxicity of the Hg‐based Ayurvedic drug Rasasindura using XAFS
Author(s) -
Ramanan Nitya,
Lahiri Debdutta,
Rajput Parasmani,
Varma Ramesh Chandra,
Arun A.,
Muraleedharan T. S.,
Pandey K. K.,
Maiti Nandita,
Jha S. N.,
Sharma Surinder M.
Publication year - 2015
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s1600577515012473
Subject(s) - nanoparticle , chemistry , x ray absorption fine structure , xanes , toxicity , molecule , extended x ray absorption fine structure , drug , covalent bond , combinatorial chemistry , nanotechnology , computational chemistry , materials science , absorption spectroscopy , pharmacology , organic chemistry , spectroscopy , medicine , physics , quantum mechanics
XANES‐ and EXAFS‐based analysis of the Ayurvedic Hg‐based nano‐drug Rasasindura has been performed to seek evidence of its non‐toxicity. Rasasindura is determined to be composed of single‐phase α‐HgS nanoparticles (size ∼24 nm), free of Hg 0 or organic molecules; its structure is determined to be robust (<3% defects). The non‐existence of Hg 0 implies the absence of Hg‐based toxicity and establishes that chemical form, rather than content of heavy metals, is the correct parameter for evaluating the toxicity in these drugs. The stable α‐HgS form (strong Hg—S covalent bond and robust particle character) ensures the integrity of the drug during delivery and prevention of its reduction to Hg 0 within the human body. Further, these comparative studies establish that structural parameters (size dispersion, coordination configuration) are better controlled in Rasasindura . This places the Ayurvedic synthesis method on par with contemporary techniques of nanoparticle synthesis.