8 Matching Annotations
- May 2019
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shodhganga.inflibnet.ac.in shodhganga.inflibnet.ac.in
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as well as commercial methods (MN kit, Germany; Mo-Bio kit, CA, USA; Zymo soil DNA kit, CA, USA) according to the manufacturer’s protocols and compared in terms of DNA yield and purity.
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The soil DNA from Pantnagar and Lonar soil samples were also extracted by various manual (Desai and Madamwar, 2007; Agarwal et al., 2001; Yamamoto et al., 1998
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sg.inflibnet.ac.in sg.inflibnet.ac.in
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mg, 0.03 mmol) in 95% aqueous pyridine (1 ml) was added. After 30 min CH2Cb was added and the solution was washed successively with cold 1 M Na2S203 (2 x 5 ml) and cold 1 M TEA hydrogen carbonate (2 x 5 ml), dried over Na2S04 and concentrated. The residue was purified by silica column chromatography (1.5% CH30H in CH2Cb with 0.1 % Et3N); Rf = 0.54 in 20% CH30H in CH2CI2; 1 H NMR: 8 -0.01 (s, 6H, Me~iCMe3), 0.84 (s, 9H, Me2SiCMe3), 1.95-2.11 (m, 18H, OAc), 3.62 (m), 3.88 (m), 4.2 (m), 4.5 (m), 4.9 (m, 2H, H-2', 3'), 5.28 (m, 3H, H-1, 2, 3), 5.44 (m, 1 H, CH=CH2); 31 P NMR .8-2.68; ESMS (mlz) : 925.3 (M-Et3N-H)". Dec-9-enyl-6-dihydroxyl-4-~-D-galactopyranosyl-a-D-mannopyranosyl phospha te triethylammonium salt (55). A solution of aqueous HF (48%) in CH3CN (5:95, 400 Ill) was added to compound 54 (10 mg, 0.009 mmol) at 0 aC. The solution was stirred at 0 aC for 2 h. The reaction was quenched by the addition of the aqueous NaHC03 solution until effervescence ceased and diluted with CH2CI2. The organic layer was extracted with water and TEAS solution thoroughly, dried over Na2S04 and concentrated to give dec-9-enyl-2,3,4-tri-O-acetyl-4-~-D-galactopyranosyl-a-Dmannopyranosyl phosphate triethylammonium salt; ESMS (m/z): 811.4 (M-EtsN-H)". A solution of oxalyl chloride (0.38 mg, 1.5 Ill, 0.003 mmol) in anhydrous CH2CI2 (50 Ill) was cooled to -78 aC and DMSO (0.47 mg, 1.7 Ill, 0.006 mmol) was added, followed by the addition of a solution of dec-9-enyl-2,3,4-tri-O-acetyl-4-~-Dgalactopyranosyl-a-D-mannopyranosyl phosphate (7 mg, 0.007 mmol) in CH2CI2 (100 Ill). The mixture was stirred for another 30 minutes and then triethylamine (10 Ill) was added. The solution was brought to rt, water was added and the mixture was extracted with CH2Cb. The organic layer was dried over Na2S04 to give the aldehyde 55. Dec-9-enyl-6-dihydroxyl-4-~-D-galactopyranosyl-a-D-mannopyranosyl phosphate triethylammonium salt (56). The residue was taken in a mixture of CH30H:water:triethylamine (5:3:2, 1.6 ml) and stirred for 2 days at rt. The reaction mixture was concentrated and the residue was repeatedly lyophilized to yield 56.
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Dec-9-enyl-2,3,4-tri-O-acetYI-[6-0-(t-butYldimethYlsilyl)-4-~-D-galactopyranosyl] -a-D-mannopyranosyl phosphate tri ethylammonium salt (54). A mixture of H-phosphonate 6 (from scheme 1, 50 mg, 0.057 mmol) and dec-9-en-1-01 (30 Ill, 0.172 mmol) was dried by evaporation of pyridine (2 x 0.5 ml). The residue was dissolved in anhydrous pyridine (1 ml), pivaloyl chloride (22 Ill, 0.172 mmol) was added, and the mixture was stirred at rt for 1 h whereafter a freshly prepared solution of iodine (6
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was diluted with water and the aqueous layer was thoroughly extracted with ethyl acetate (15 ml x 2). The organic layer was dried over Na2S04, concentrated and dried to yield C4C] labelled stearyl alcohol 51. [14C]-Stearyl-2,3,6-tetra-O-acetyl-4-0-(2,3,4 ,6-tretra-O-acetyl-~-D-gal actopyrano syl)-a-D-mannopyranosyl phosphate triethylammonium salt (52). A mixture of H-phosphonate 47 (296 mg, 0.37 mmol) and [14C] stearyl alcohol (51,100 mg, 0.37 mmol) was dried by evaporation of pyridine (2 x 3 ml). The residue was dissolved in anhydrous pyridine (5 ml), adamantane carbonyl chloride (160 mg, 0.8 mmol) was added, and the mixture was stirred at rt for 1 h whereafter a freshly prepared solution of iodine (160 mg, 0.63 mmol) in 95% aqueous pyridine (5 ml) was added. After 30 min CH2Cb was added and the solution was washed successively with cold 1 M Na2S203 (2 x 10 ml) and cold 1 M TEA hydrogen carbonate (2 x 10 ml), dried over Na2S04 and concentrated. The residue was purified by silica column chromatography (2.5% CH30H in CH2CI2 with 1 % Et3N) to afford 52. [14C]-Stearyl-4-~-D-galactopyranosyl-a-D-mannopyranosyI phosphate triethyl ammonium salt (53). To a solution of compound 4 (75 mg, 0.07 mmol) in anhydrous CH30H (12.5 ml) was added anhydrous sodium carbonate (80 mg, 0.75 mmol). The mixture was stirred at rt for 2 h, whereafter sodium carbonate was removed by filtration. The solvent was evaporated and residue concentrated to yield 53; R,= 0.55 in 10: 1 0:3 CH30H:CH2CI2:O.25% KC!.
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[14C]-Stearyl alcohol (51). Stearic acid (50,100 mg) in anhydrous THF (1 mL) was diluted with C4C] stearic acid (1.2 mL, 120 !lCi). To this was added THF-borane complex (4 mL). The mixture was refluxed at 90°C for 36 h. The contents were then poured onto CH3COOH:H20 (8 mL, 1:1), taken in a separating funnel. The mixture
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Polycondensation. Compound 26 (25 mg, 0.033 mmol) was dried by evaporation of pyridine (500 III x 3) therefrom. The residue was dissolved in 10:1 pyridine:triethylamine (40 Ill), and pivaloyl chloride (9 Ill, 0.073 mmol) was added. Another lot of pivaloyl chloride (6 Ill, 0.04B mmol) was added in 45 min. After 3 h, the mixture became viscous, and a freshly prepared solution of iodine (220 Ill, 35 mg, 0.137 mmol in pyridine-water, 95:5) was added. After 2 h, CHCI3 was added and the organic layer was successively washed with cold 1 M aqueous Na2S203 solution and 1 Mice-cold TEAB buffer, dried over Na2S04 and concentrated to dryness to afford 27. For final deprotection, above residue was dissolved in 0.1 M NaOMe solution in CH30H (440 Ill), 1,4-dioxane (BOO Ill), and CHCI3 (BOO Ill). The mixture was stirred at rt for 7 h and left at 4 °C for 16 h, then diluted with CH30H, deionized with Dowex 50W-X4 (H+) resin, filtered and immediately neutralized with drops of triethylamine. The mixture was concentrated to dryness to afford fully deprotected phosphoglycans (28). 31 P (D~O): 8 -1.73, O.BB. Preliminary CD analysis of Phosphoglycans. The above polycondensation product (28) was lyophilized repeatedly and then redissolved in H20 (400 Jll). This solution was taken in a glass cuvette (300 Ill, 1 mm pathlength). It's CD spectra was recorded on a spectropolarimeter (JASCO, J-710) between 175-250 nm at 25°C. For reference, the CD spectra of agarose (15% W/V)87 was also recorded under the same conditions as mentioned above.
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Triethylammonium 2,3,6-tri-o.acetyl-4-o.(2,3,4-tri-o.acetyl-~-D-galactopyrana syl)-a-D-manno pyranosyl hydrogen phosphonate (26). Compound 6 (30 mg, 0.034 mmol) was dissolved in a mixture of acetic acid-water-THF (3:1:1,2.5 ml). The mixture was stirred at 40°C for 9 h, after which the solvent was evaporated off under vacuo at rt. To remove excess of acid, water (1 ml) was added and evaporated off twice to afford 26 in quantitative yield; 1H NMR (CDCI3, 300 MHz) 0 1.95-2.09 (m, 21 H), 3.49-3.68 (m, 4H), 3.88 (m, 1 H), 4.14 (m, 1 H), 4.36 (d, J = 4.5 Hz, 1 H), 4.47 (d, J = 7.8 Hz, 1 H), 4.95 (dd, J = 3_3 and 7_8 Hz, 1 H), 5.05 (dd, J = 2_1 and 7.8 Hz, 1 H), 5.21 (dd, J = 2.1 and 3.6 Hz, 1 H), 5.41 (d, J = 3.3 Hz, 1 H), 5.48 (dd, J = 2.1 and 7.8 Hz, 1 H), 7.99 ( d, JH,p = 637_0 Hz, 1 H); 13C NMR (CDCI3, 75 MHz) 0 20.48-20.76, 60.10, 62.42, 66.57, 69.36, 69.53, 69.69, 71.20, 73.30, 73.86, 91.59, 92.54, 101_09, 169.13-170.49; 31p (CDCI3): 00.22; ESMS mlz657.3 (M-EhN-Hr.
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