received by the International Bureau on 01 December 2014 (01.12.2014)

I . Spherical shaped Nanostructured carboxy cellulose characterised by

a) carboxy content in the range of 1.0% to 24%;

b) molecular weight of 50-70 degree of polymerization; and

c) particle size in the range of 10-100 nm,

said spherical shaped Nanostructured carboxy cellulose selected from 6- carboxycellulose and 2,3,6 tricarboxycellulose, said 2,3,6 tricarboxycellulose having carboxy content in the range of 1 -25% at C6 position of glucose unit of cellulose and in the range of 1-75% at C2 and C3 together of glucose unit of cellulose,

said spherical shaped nano structure carboxy cellulose prepared by a process comprising:

a) oxidizing a-cellulose derived from sugarcane bagasse or from cotton in the presence of 2: 1 ratio (v/v) of 60-70% HN03 and 75- 85%H3P04 and NaN02 (1.2- l.,6w/v%) at temperature ranging from. 30°C--80^eC for reaction time of 1 hr to 48 hrs to obtain nanostructured spherical 6- carboxycellulose;

b) optionally, oxidizing α-cellulose derived from sugarcane bagasse or from cotton to 2,3,6 tricarboxycellulose by subjecting a-cellulose to oxidation in presence of · sodium periodate to obtain 2,3 dialdehyde cellulose and oxidazing 2,3 ch^'aldehyde cellulose in presenc of nitoros producing agent, 60-65% 1-1 03 and 75-85% H3P04 in 2.1 (v) ratio, accompanied by NaN02 (1.2-1.6%)at temperature in the range of 30-80°C for reaction time of 1 -20 hours to afford nanostructured 2,3,6 tricarboxycellulose.

2. The process according to claim 1 , wherein cellulose used in step (a) and (b) is derived from, sugarcane bagasse or from cotton. , The process according to claim 1 , wherein the nanostructured carboxycellulose is in the form of spherical nanoparticles, , The process according to claim 1 , wherein the size of nanoparticles of carboxy cellulose is in the range of 10-lOO.nm. , The process according to claim 1, wherein the imnostructured carboxycellulose exhibits solubility in dilute alkali solution selected from 0.1-1 5% of NaOH and organic solvents selected from the group consisting of acetonitriJe, dimetbylacetamide, dimethyl sulfoxide, dioxane, acetone, methanol, ethanol, chloroform, dichloromethane, tetrahydrofurane, toluene, dimethylformamide, pyridine. , A pharmaceutical composition comprises nanoparticles of carboxy cellulose according to claim I, alone or along with one or more the pharmaceutically acceptable excipicnt(s) and/or vebicic(s), and/or carrier(s) useful for treating microbial infections wherein the bacterial species is selected from M, tuberculosis, E colt, Ji. subtUix S, aureus, , A pharmaceutical composition according to claim 6, alone or together with phtuntiacetitically acceptable excipient(s) and/or vehicle(s), wherein the MIC value is obtained in between 2-5mg/ml. , A method of inhibiting growth of microbes in mammals, comprising administrating nanoparticles of carboxy or oxidized cellulose according to claim 1, alone or together with pharmaceutically acceptable excipient(s) and/or vehicle(s). , A method of treating according to claim 6, wherein the microbes tire selected from the group consisting of bacteria, virus, fungi, parasites, yeast, mould; preferably bacteria selected from group M, tuberculosis, E coli, B, subtilis S, aureus. 0, Use of carboxy cellulose according to claim 1 , as anti-microbial material in wound dressing gauze, hemostatic material, biocompatible material, biocomposites, detergent builder, catalyst, ion-exchange resin, polymer and hydrophobic cellulose nanoparticles,

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