TY - JOUR
T1 - In vitro biotransformations of isocupressic acid by cow rumen preparations
T2 - Formation of agathic and dihydroagathic acids
AU - Lin, Shwu Jiuan
AU - Short, Robert E.
AU - Ford, Stephen P.
AU - Grings, Elaine E.
AU - Rosazza, John P N
PY - 1998/1
Y1 - 1998/1
N2 - Isocupressic acid [15-hydroxylabda-8(17),13E-dien-19-oic acid] (1) was incubated under anaerobic conditions for 48 h in an in vitro ruminal fluid mixture and was transformed into two metabolites. The two metabolites were identified by GC/MS as agathic acid [labda-8(17),13(E)-diene-15,19-dioic acid] (4E) and dihydroagathic acid [labda-8(17)-ene-15,19-dioic acid] (6). Metabolite identities were confirmed by chemical conversions of isocupressic acid (1) and imbricataloic acid (5) into 4E and 6, respectively. Structures of synthetic metabolites were confirmed by 1H and 13C NMR, specific rotation, GC/MS, and high-resolution mass spectrometry. Plasma obtained from cows that were fed Ponderosa pine needles contained (13R,S)-dihydroagathic acid (6) but not isocupressic acid (1) or 4E. The results suggest that isocupressic acid (1) is metabolically oxidized to agathic acid (4E), subsequently reduced to (13R,S)-dihydroagathic acid (6) in the rumen, and then absorbed into the bloodstream of cattle.
AB - Isocupressic acid [15-hydroxylabda-8(17),13E-dien-19-oic acid] (1) was incubated under anaerobic conditions for 48 h in an in vitro ruminal fluid mixture and was transformed into two metabolites. The two metabolites were identified by GC/MS as agathic acid [labda-8(17),13(E)-diene-15,19-dioic acid] (4E) and dihydroagathic acid [labda-8(17)-ene-15,19-dioic acid] (6). Metabolite identities were confirmed by chemical conversions of isocupressic acid (1) and imbricataloic acid (5) into 4E and 6, respectively. Structures of synthetic metabolites were confirmed by 1H and 13C NMR, specific rotation, GC/MS, and high-resolution mass spectrometry. Plasma obtained from cows that were fed Ponderosa pine needles contained (13R,S)-dihydroagathic acid (6) but not isocupressic acid (1) or 4E. The results suggest that isocupressic acid (1) is metabolically oxidized to agathic acid (4E), subsequently reduced to (13R,S)-dihydroagathic acid (6) in the rumen, and then absorbed into the bloodstream of cattle.
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U2 - 10.1021/np970372u
DO - 10.1021/np970372u
M3 - Article
C2 - 9461652
AN - SCOPUS:0031885621
VL - 61
SP - 51
EP - 56
JO - Journal of Natural Products
JF - Journal of Natural Products
SN - 0163-3864
IS - 1
ER -