Characterization of osthenol metabolism in vivo and its pharmacokinetics.

Osthenol, a prenylated coumarin, is a C8-prenylated derivative of umbelliferone isolated from the root of Angelica koreana and Angelica dahurica, an intermediate and is known as a major metabolite of desmethyl-osthole.The various pharmacological effects of osthenol have been reported. In previous studies, we investigated five hydroxylated metabolites by cytochromes P450 (CYP) and glucuronide conjugates of osthenol by uridine diphosphate-glucuronosyltransferases (UGTs). However, osthenol have very few studies have been reported on its pharmacokinetic (PK) profiling, we reported the PK parameters in mouse of osthenol through this study.After oral (5 and 20 mg/kg) and intravenous (5 mg/kg) administration, the concentration of osthenol in plasma was determined by LC-MS/MS. The quantitative method was validated in terms of linearity, accuracy, and precision. When 5 and 20 mg/kg of osthenol were orally administered, the bioavailability (BA) was found to be very low at 0.43 and 0.02%, respectively.In fact, osthenol was mostly metabolized to a two-Phase II conjugates, a sulfonyl and glucuronyl-osthenol, in the blood, which was determined by LC-HR/MS analysis of the blood sample. Because osthenol is rapidly metabolized to two conjugates by first-pass effect the BA of osthenol is low after oral administration.

Osthenol, a prenylated coumarin, as a monoamine oxidase A inhibitor with high selectivity.

Osthenol (6), a prenylated coumarin isolated from the dried roots of Angelica pubescens, potently and selectively inhibited recombinant human monoamine oxidase-A (hMAO-A) with an IC50 value of 0.74 µM and showed a high selectivity index (SI > 81.1) for hMAO-A versus hMAO-B. Compound 6 was a reversible competitive hMAO-A inhibitor (Ki = 0.26 µM) with a potency greater than toloxatone (IC50 = 0.93 µM), a marketed drug. Isopsoralen (3) and bakuchicin (1), furanocoumarin derivatives isolated from Psoralea corylifolia L., showed slightly higher IC50 values (0.88 and 1.78 µM, respectively) for hMAO-A than 6, but had low SI values (3.1 for both). Other coumarins tested did not effectively inhibit hMAO-A or hMAO-B. A structural comparison suggested that the 8-(3,3-dimethylallyl) group of 6 increased its inhibitory activity against hMAO-A compared with the 6-methoxy group of scopoletin (4). Molecular docking simulations revealed that the binding affinity of 6 for hMAO-A (-8.5 kcal/mol) was greater than that for hMAO-B (-5.6 kcal/mol) and that of 4 for hMAO-A (-7.3 kcal/mol). Docking simulations also implied that 6 interacted with hMAO-A at Phe208 and with hMAO-B at Ile199 by carbon hydrogen bondings. Our findings suggest that osthenol, derived from natural products, is a selective and potent reversible inhibitor of MAO-A, and can be regarded a potential lead compound for the design of novel reversible MAO-A inhibitors.

Characterization of CYPs and UGTs Involved in Human Liver Microsomal Metabolism of Osthenol.

Osthenol is a prenylated coumarin isolated from the root of Angelica koreana and Angelica dahurica, and is an O-demethylated metabolite of osthole in vivo. Its various pharmacological effects have been reported previously. The metabolic pathway of osthenol was partially confirmed in rat osthole studies, and 11 metabolic products were identified in rat urine. However, the metabolic pathway of osthenol in human liver microsomes (HLM) has not been reported. In this study, we elucidated the structure of generated metabolites using a high-resolution quadrupole-orbitrap mass spectrometer (HR-MS/MS) and characterized the major human cytochrome P450 (CYP) and uridine 5'-diphospho-glucuronosyltransferase (UGT) isozymes involved in osthenol metabolism in human liver microsomes (HLMs). We identified seven metabolites (M1-M7) in HLMs after incubation in the presence of nicotinamide adenine dinucleotide phosphate (NADPH) and uridine 5'-diphosphoglucuronic acid (UDPGA). As a result, we demonstrated that osthenol is metabolized to five mono-hydroxyl metabolites (M1-M5) by CYP2D6, 1A2, and 3A4, respectively, a 7-O-glucuronide conjugate (M6) by UGT1A9, and a hydroxyl-glucuronide (M7) from M5 by UGT1A3 in HLMs. We also found that glucuronidation is the dominant metabolic pathway of osthenol in HLMs.

[Chemical constituents from lipophilic parts in roots of Angelica dahurica cv.Yubaizhi].

The chemical constituents from lipophilic parts in the roots of Angelica dahurica cv. Yubaizhi were studied in this paper. The compounds were separated and purified by repeated column chromatographic methods on silica gel and HPLC, and the chemical structures of compounds were determined by spectral data analyses. Thirty-three compounds were obtained and identified as isoimperatorin (1), imperatorin (2), stigmasterol (3), isooxypeucedanin (4), pabulenol (5), psoralen (6), bergapten (7), isodemethylfuropinarine (8), phellopterin (9), osthenol (10), alloimperatorin (11), xanthotoxin (12), xanthotoxol (13), isopimpinellin (14), alloisoimperatorin (15), ß-sitosterol (16), oxyalloimperatorin (17), pabularinone (18), 5-hydroxy-8-methoxypsoralen (19), columbianetin (20), heracol (21), isogosferol (22), 2″R-neobyakangelicol (23), byakangelicin ethoxide (24), byakangelicin (25), oxypeucedanin hydrate (26), uracil (27), umbelliferone (28), bergaptol (29), demethylfuropinarine (30), isobyakangelicol (31), oxypeucedanin ethanolate (32), heraclenol (33). Among them, compounds 8, 10, 17, 21, and 30 were obtained from the roots of title plant for the first time.

Chemical constituents from lipophilic parts in roots of Angelica dahurica cv.Yubaizhi / 中国中药杂志

The chemical constituents from lipophilic parts in the roots of Angelica dahurica cv. Yubaizhi were studied in this paper. The compounds were separated and purified by repeated column chromatographic methods on silica gel and HPLC, and the chemical structures of compounds were determined by spectral data analyses. Thirty-three compounds were obtained and identified as isoimperatorin (1), imperatorin (2), stigmasterol (3), isooxypeucedanin (4), pabulenol (5), psoralen (6), bergapten (7), isodemethylfuropinarine (8), phellopterin (9), osthenol (10), alloimperatorin (11), xanthotoxin (12), xanthotoxol (13), isopimpinellin (14), alloisoimperatorin (15), β-sitosterol (16), oxyalloimperatorin (17), pabularinone (18), 5-hydroxy-8-methoxypsoralen (19), columbianetin (20), heracol (21), isogosferol (22), 2″R-neobyakangelicol (23), byakangelicin ethoxide (24), byakangelicin (25), oxypeucedanin hydrate (26), uracil (27), umbelliferone (28), bergaptol (29), demethylfuropinarine (30), isobyakangelicol (31), oxypeucedanin ethanolate (32), heraclenol (33). Among them, compounds 8, 10, 17, 21, and 30 were obtained from the roots of title plant for the first time.