Synthesis and characterization of carboxymethyl cellulose from office waste paper: a greener approach towards waste management.

In the present study, functionalization of mixed office waste (MOW) paper has been carried out to synthesize carboxymethyl cellulose, a most widely used product for various applications. MOW was pulped and deinked prior to carboxymethylation. The deinked pulp yield was 80.62 ± 2.0% with 72.30 ± 1.50% deinkability factor. The deinked pulp was converted to CMC by alkalization followed by etherification using NaOH and ClCH2COONa respectively, in an alcoholic medium. Maximum degree of substitution (DS) (1.07) of prepared CMC was achieved at 50 °C with 0.094 M and 0.108 M concentrations of NaOH and ClCH2COONa respectively for 3h reaction time. The rheological characteristics of 1-3% aqueous solution of optimized CMC product showed the non-Newtonian pseudoplastic behavior. Fourier transform infra red (FTIR), nuclear magnetic resonance (NMR) and scanning electron microscope (SEM) study were used to characterize the CMC product.

Synthesis and optimization of antitubercular activities in a series of 4-(aryloxy)phenyl cyclopropyl methanols.

A series of [4-(aryloxy)phenyl]cyclopropyl methanones were synthesized by reaction of different benzyl alcohols with 4-chloro-4'-fluorobutyrophenone in DMF in the presence of NaH/TBAB. The methanones were further reduced to respective methanols. The antitubercular activity of these compounds was evaluated in vitro against Mycobacterium tuberculosis H37Rv. Compounds 19, 21, 35, 36 and 37 have shown minimum inhibitory concentration (MIC) of 3.12 µg/mL, while compounds 14, 25 and 18 have shown MIC of 1.56 µg/mL and 0.78 µg/mL respectively. One of the compounds, cyclopropyl-4-[4-(2-piperidin-1-yl-ethoxy)benzyloxy]phenyl}methanol (36) showed 98% killing of intracellular bacilli in mouse bone marrow derived macrophages and was active against MDR, XDR and rifampicin clinical isolates resistant strains with MIC 12.5 µg/mL. Compound 36 was orally active in vivo in mice against M. tuberculosis H37Rv with an increase in MST by 6 days with 1 log reduction in the bacillary density in lungs as compared to control on 30th day after infection.

An efficient synthesis of tetramic acid derivatives with extended conjugation from L-ascorbic acid.

BACKGROUND: Tetramic acids with polyenyl substituents are an important class of compounds in medicinal chemistry. Both solid and solution phase syntheses of such molecules have been reported recently. Thiolactomycin, a clinical candidate for treatment of tuberculosis has led to further explorations in this class. We have recently developed an efficient synthesis of tetramic acids derivatives from L-ascorbic acid. In continuation of this work, we have synthesised dienyl tetramic acid derivatives. RESULTS: 5,6-O-isopropylidene-ascorbic acid on reaction with DBU led to the formation of tetronolactonyl allyl alcohol, which on oxidation with pyridinium chlorochromate gave the respective tetranolactonyl allylic aldehydes. Wittig olefination followed by reaction of the resulting tetranolactonyl dienyl esters with different amines resulted in the respective 5-hydroxy lactams. Subsequent dehydration of the hydroxy lactams with p-toluene sulphonic acid afforded the dienyl tetramic acid derivatives. All reactions were performed at ambient temperature and the yields are good. CONCLUSION: An efficient and practical method for the synthesis of dienyl tetramic acid derivatives from inexpensive and easily accessible ascorbic acid has been developed. The compounds bear structural similarities to the tetramic acid based polyenic antibiotics and thus this method offers a new and short route for the synthesis of tetramic acid derivatives of biological significance.

Asymmetric organocatalysis with glycosyl-beta-amino acids: direct asymmetric aldol reaction of acetone with aldehydes.

Direct asymmetric aldol reaction of acetone with aromatic aldehydes was achieved in good yields and high enantioselectivity using 5-amino-5-deoxy-beta-L-ido-(alpha-D-gluco)-heptofuranuronic acids as a new class of organocatalysts.