Novel antimicrobial diterpenoids from Turraeanthus africanus.
The dichloromethane-methanol (1/1) extract of the stem bark of Turraeanthus africanus (Meliaceae) showed remarkable antimicrobial activity against Cryptococcus neoformans, Staphylococcus aureus and methicillin-resistant S. aureus. Phytochemical investigation of this extract afforded six new diterpenoid derivatives, (+)-16-acetoxy-12,15-epoxylabda-8(17),12,14-triene ( 3), [16( E),12 S,15 R]-16-acetoxy-12,15-epoxy-15-isopropoxy- ent-labda-8(17),13(16)-diene (turraeanin A, 4), [16( E),12 R,15 S]-16-acetoxy-12,15-epoxy-15-isopropoxy- ent-labda-8(17),13(16)-diene (turraeanin B, 5), [16( E),12 S,15 R]-16-acetoxy-12,15-epoxy-15-methoxy- ent-labda-8(17),13(16)-diene (turraeanin C, 6), [16( E),12 R,15 S]-16-acetoxy-12,15-epoxy-15-methoxy- ent-labda-8(17),13(16)-diene (turraeanin D, 7) and (12 S,13 S,15 R)-12,15-epoxy-15-methoxy- ent-labd-8(17)-en-16-al (turraeanin E, 9) together with the known compounds, 15,16-epoxy- ent-labda-8(17),13(16),14-triene ( 1), (+)-pumiloxide ( 2), ent-labda-8(17),12 ( E)-diene-15,16-dial ( 8) and 16-acetoxy-12( R),15-epoxy-15beta-hydroxylabda-8(17),13 (16)-diene ( 10). Compound 10 was obtained as its acetoxy derivative ( 10a) and compound 11 was the product of hydrolysis of 6. Antimicrobial activity of the isolates was assayed and compounds 8, 9, 10a and 11 exhibited significant activities.
Tatsimo
Simplice Joel
SJ
Department of Organic Chemistry, University of Yaounde, Yaounde, Cameroon.
Tane
Pierre
P
Srinivas
Pullela V
PV
Sondengam
Beibam L
BL
Melissa
Jacob
J
Okunji
Christopher O
CO
Schuster
Brian M
BM
Iwu
Maurice M
MM
Khan
Ikhlas A
IA
D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D000998:Antiviral Agents / Q000737:chemistry / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects; D003455:Cryptococcus neoformans / Q000187:drug effects; D004224:Diterpenes / Q000737:chemistry* / Q000494:pharmacology*; D029582:Meliaceae / Q000737:chemistry*; D016106:Methicillin Resistance; D015394:Molecular Structure; D008517:Phytotherapy; D024301:Plant Bark / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D013211:Staphylococcus aureus / Q000187:drug effects
D000900:Anti-Bacterial Agents; D000998:Antiviral Agents; D004224:Diterpenes