Table 1 The observed IR bands (cm-1) of the extract compounds of Betulaceae species, and the pure references species betulin (B), lupeol (L) and betulinic acid (BA) together with their assignments based on our previous DFT calculations[3]of betulin
IR | IR | IR | IR | IR | IR | Assignments |
|---|---|---|---|---|---|---|
Betula utilisextract from ref.[11] | Isolated triterpenes fromBetula Pendula Roth,ref.[10] | Extract BC1 fromBetula Pendula Roth | Betulin (B) | Betulinic acid (BA) | Lupeol (L) | |
3433 (B) | - | - | 3471vs | 3431 | - | ν (OH) |
- | - | - | 3465 sh | - | - | ν (OH)) |
- | 3384 (BA) | 3362 s | 3362 s | - | 3309 s | ν (OH) |
3348 (B) | ||||||
3308 (L) | ||||||
- | - | - | 3212 m | 3225 | - | ν (OH) |
- | - | 2940 vs | 2968 vs | 2943 vs | 2982 s | νas(CH3) + νas(CH2) + νas(CH) |
2957 s | ||||||
2942 vs | ||||||
- | - | - | 2929 vs | - | 2928 sh | νas(CH2) + ν(CH2) + ν(CH) |
- | 2870 (BA) | 2867 s | 2866 vs | 2878 vs | 2874 vs | + ν(CH2+ ν(CH2) |
2868 (B) | 2845 sh | |||||
2872(L) | ||||||
1725 (B) 1672 (BA) | 1686, BA | 1709-1684, broad | 1735 w, 1708 sh | 1716 sh, 1681 vs | - | ν (C = O) |
1648 (B) | 1638)(B) | 1642 | 1642 m | 1642 m | 1642 m | δ(CH2) + ν((C = C) + δ(C-C-H) |
1630 (L) | ||||||
1600 (B) 1560 (B) | - | 1601 | - | - | - | - |
- | 1468 (L) 1432 (BA, B) | 1484 m 1452 s | 1485 m 1450 s | 1451 | 1453 m | δ(CH3) + δ(CH2) |
- | 1362 (O-H, BA); 1380 (L) 1388 (B) | 1373 m | 1373 m | 1377 m | 1374 m | δ(CH3) + δ(CH2) |
1230 (B) 1240(BA) | - | - | - | 1232 m | - | δ(OH) + τ(CH2) + δ(CH) |
- | 1156 (BA) | 1190 m | 1190 m | 1190 m | 1190 m | ν(C-C) + δ(OH) + τ(CH2) + δ(CH) |
1028 (BA) | 920 (L) | 1028 s | 1032 ms | 1043 m | 1046 m | ν(C-O) from CH2-OH, + δ(CH) + ρ(CH3, CH2) |
- | - | 1006 sh | 1006 vs | - | - | ν(C-O) + δ(CH) + ρ(CH3-CH2) |
984 m | ||||||
881 (B) | 920 (L) | 881 ms | 875 ms | 885 ms | 895 s | ω (H-C-H) umbrella alkene |