... ban tdng hgp tir a -amyrin de tim hieu md'i lien quan giua ciu tnic vi hoat tinh [14] 23 24 2: R = H a -amyrin 3: R = Ac a -amyrin acetat maculata, Populus tremuloides [14] a -Amyrin va din xuat ... 440 [M ]"^ (C30H48O2), cho thiy ehi cd mot nhdm keton bi khir Phd 'H -, '^C-NMR va DEPT ciia chat tuong tu nhu cua chit 2, chi khac la cd tfn hieu cua nhdm keton (4:199,77) Khi so sinh phd '"" C-NMR ... 40,90 16,35 21,11 15,59 18,51 20,52 28,81 28,10 17,41 - 'Tin hieu co cudng ldn hon; "Tin hieu co cudng nho hon; "" Tin hieu khong nhin thay COOCKHS COGCeHs AcO' lb; Acid 3-/?-a.\etoxy-bauer-7-en-28-oic...