[PubMed] [Google Scholar] 8. ability to inhibit the enzymatic hydrolysis of 18. Similarly, methylating the hydroxyl group at C-4 in 1 affording galactonoamidine 1c (Table 1, access Piperine (1-Piperoylpiperidine) 4) diminishes the hydrogen bonding ability of the galactonoamidine 1 and launched steric constraints, but to a somewhat lesser degree than 1b accounting for the maintained free hydroxyl group at C-2 in 1c. Piperine (1-Piperoylpiperidine) Galactonoamidine 1c decreases the enzyme activity during the hydrolysis of the model compound more than 530-collapse in comparison to 1 pointing at a loss of stabilizing H-bonding relationships and improved steric constraints upon binding of the inhibitor in the active site. Docking experiments of the amidines 1 and 1aCc Piperine (1-Piperoylpiperidine) in the active site of -galactosidase (was from Sigma-Aldrich as lyophilized powder and used as received. 4.3. Synthesis of perbenzylated glyconolactones 4.3.1. 3,4,6-Tri-O-benzyl-2-deoxy-D-lyxo-hexono-1,5-lactone (3a)11C16 The compound was prepared according to literature methods;11C16 yielding 3a like a colorless oil (7.50 g, 63 %); Rf 0.42 (SiO2, cyclohexane/ethyl acetate, 2/1 v/v); H (acetone-d6) 7.47 C 7.17 (m, 15 H), 4.96 (d, 11.3, 1 H), 4.72 (dd, 12.0, 25.3, 2 H), 4.33 (d, 1.8, 1 H), 4.21 (ddd, 2.1, 6.7, 11.0, 1 H), 3.76 (dd, 6.5, 9.5, 1 H), 3.67 (dd, 6.3, 9.5, 1 H), 2.90 (ddd, 1.0, 6.3, 17.8, 1 H), 2.85 C 2.71 (m, 3 H); C (acetone-d6) 169.1, 139.6, 139.4, 139.2, 129.2, 129.2, 129.1, 128.8, 128.7, 128.5, 128.4, 128.4, 78.7, 75.6, 75.0, 73.8, 72.1, 71.3, 69.7, 34.0; the spectral data of 3a match those HOX1H previously reported.15 4.3.2. p-Tolyl 3,4-O-isopropylidene-1-thio–D-galactopyranoside (4)38 The compound was synthesized by adapting a protocol for any related compound with different aglycon.17 Colorless oil; H (CDCl3) 7.44 (dt, 8.0, 1.8, 2H), 7.13 (d, 7.8, 2H), 4.41 (d, 10.3, 1H), 4.18 (dd, 5.5, 2.3, 1H), 4.11 (dd, 7.0, 5.5, 1H), 3.98 (dd, 11.3, 7.0, 1H), 3.84 C 3.89 (m, 1H), 3.81 (dd, 11.5, 4.3, 1H), 3.55 (dd, 10.2, 6.9, 4H), 2.34 (s, 3H), 1.43 (s, 3H), 1.34 (s, 3H); C (CDCl3) 138.2, 132.8, 129.7, 128.0, 110.3, 87.9, 79.2, 77.0, 73.8, 71.4, 62.4, 27.9, 26.3, 21.0; the spectral data of 4 match those previously reported.38 4.3.3. p-Tolyl 3,4-O-isopropylidene-6-O-trityl-1-thio–D-galactopyranoside (5) The synthesis was performed according to a protocol for closely related compound explained by Kakarla et al.39 Triphenylmethyl chloride (18.72 g, 0.0673 mol, 1.46 eq.) was added to the perfect solution is of 4 (15.00 g, 0.0460 mol) in 60 mL pyridine and heated to 80 C for 2 h. The reaction was performed with this set-up in duplicate. The two batches were combined after cooling of the reaction mixtures, 50 mL of water were added, and the producing answer was extracted three times Piperine (1-Piperoylpiperidine) with 200 Piperine (1-Piperoylpiperidine) mL ethyl acetate each. The combined organic layers were washed with 80 mL water, 80 mL brine and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated to dryness in vacuum, and the acquired residue was purified by column chromatography over silica gel (hexane/ethyl acetate, 6/1 C 3/1, v/v) to afford compound 5 (31.1 g, 55.78 mmol, 91 %) like a colorless solid; mp 71C73 C; Rf 0.16 (SiO2, cyclohexane/ethyl acetate, 4/1, v/v); H (CD2Cl2) 7.52 C 7.43 (m, 8 H), 7.37 C 7.23 (m, 9 H), 7.11 (d, 8.0, 2 H), 4.39 (d, 10.3, 1 H), 4.14 (dd, 2.1, 5.4, 1 H), 3.99 (dd, 5.5, 6.8, 1 H), 3.80 (ddd, 2.0, 4.9, 7.2, 1.