Synthesis and anti-influenza activity of 2-cyanoethoxy and 2-(1H-tetrazol-5-yl)ethoxy derivatives of dammarane-type triterpenoids

Azepanodipterocarpol is potential candidate for inhibits influenza H1N1 type among other lupane, oleanane, and dammarane A-ring amino-triterpenoids

“…Alnincanone having a framework of dammarane, echinocystic acid-lupane type triterpenoid, and methyl ester of ursolic acid possess pronounced inhibiting activity against influenza type A virus (protection index 60%) and high antiviral activity against influenza type B (protection index 80%) [29]. 3-Cyanoethoxy derivatives of dammarane triterpenoids alnincanone and dipterocarpol, 3-tetrazolyl derivative of dammarolide had a considerable activity with SI 10, 9, and 26 against influenza virus A/Puerto Rico/8/34 (H1N1) [30].…”

“…3β-Amino-20(S)-hydroxy-dammar-24-en (6) Yield 89% (0.39 g); m. p. 168 °С; [α] D 20 34°(с 0.1, CHCl 3 ); δ H (500.13 MHz, CDCl 3 ) 0.73 (s, 3H, H-28), 0.74 (dd, 1H, 3 J 5-6ax = 11.7, 3 J 5-6eq = 2.2, H-5), 0.83 (s, 3H, H-19), 0.88 (s, 3H, H-30), 0.94 (s, 3H, H-29), 0.96 (s, 3H, H-18), 0.97 (ddd, 1H, 2 J = 12.7, 3 J 1ax-2ax = 12.4, 3 J 1ax-2eq = 4.1, H ax -1), 1.06 (m, 1H, H α -15), 1.14 (s, 3H, H-21), 1.23 (m, 1H, H ax -11), 1.26 (m, 1H, H ax -12), 1.27 (m, 1H, H eq -7), 1.33 (dd, 1H, 3 J 9-11ax = 11.6, 3 J 9-11eq = 2.8, H-9), 1.43 (m, 1H, H ax -6), 1.45 (tdd, 1H, 2 J = 12.4, 3 J 2ax-1ax = 12.4, 3 J 2ax-3 = 11.9, 3 J 2ax-1eq = 3.6, H ax -2), 1.46 (m, 1H, H β -15), 1.47 (t, 2H, H-22), 1.49 (m, 1H, H β -16), 1.50 (m, 1H, H eq -11), 1.53 (m, 1H, H ax -7), 1.55 (dtd, 1H, 2 J = 12.4, 3 J 2eq-3 = 4.1, 3 J 2eq-1ax = 4.1, 3 J 2eq-1eq = 3.6, H eq -2), 1.55 (m, 1H, H eq -6), 1.62 (d, 3H, 4 J 26-24 = 1.5, H-27), 1.63 (ddd, 1H, 3 J 13-17 = 12.6, 3 J 13-12ax = 10.2, 3 J 13-12eq = 3.5, H-13), 1.67 (dt, 1H, 2 J = 12.7, 3 J 1eq-2ax = 3.6, 3 J 1eq-2eq = 3.6, H eq -1), 1.69 (d, 3H, 4 J 27-24 = 1. 3-Oxo-3a-aza-20(S)-hydroxy-dammar-24-en (7) 3-Oximino-dipterocarpol [43] (1 mmol, 0.44 g) in dry dioxane (15 ml) was treated with SOCl 2 (0.4 ml), stirred at room temperature for 30…”