Six New Andrographolide Metabolites in Rats

Abstract

Andrographolide chemically designated as 2(3H)-furanone, 3-[2-[decahydro-6-hydroxy-5-(hydroxymethyl)-5,8a-dimethyl-2-methylene-1-napthalenyl] ethylidene] dihydro-4-hydroxy ( Fig. 1), is one of the main active constituents of Andrographis paniculate (BURM) NEES, a famous traditional Chinese medicine. Andrographolide has many bioactivities, such as antiinflammatory and antimicrobial, 1,2) antiplatelet aggregation, 3,4) hepatoprotective, 5,6) and anti-human immunodeficiency virus (HIV) activity. 7) Andrographolide is widely used clinically with good results, but it did not show efficacy in activity assays in vitro. Andrographolide has aroused the interest of many pharmacologists, and numerous experiments have been performed, although much remains to be clarified. A few investigations of the pharmacokinetics have been reported after oral administration of andrographolide. 8,9) However, to the best of our knowledge, there has been no report on its metabolites either in humans or animals. We isolated and analyzed the metabolites of andrographolide in blood, urine, bile, and the contents of the small intestine and stomach of rats. So far, we have identified 10 new metabolites. In this paper, six new metabolites are presented including their extraction, isolation, and identification.Metabolite 5 (M-5), colorless powder, melting point Ͼ300°C (decomposed), was positive for the Legal and Kedde reactions, suggesting the presence of an a,b-unsaturated lactone. The IR spectrum showed the presence of hydroxyl (3433 cm Ϫ1 ), ester carbonyl (1744 cm Ϫ1 ), carbon-carbon double bond (1643 cm Ϫ1 ), and sulfonate (1205 cm Ϫ1 ) groups in the molecule. In the high-resolution second ionization mass spectrum (HR-SI-MS), a quasimolecular peak [MϪH] Ϫ at m/z 493.1205 (Calcd 493.1207) was seen, and thus the molecular formula of C 20 H 30 O 10 S 2 was derived.Wide variation in the chemical shifts at C 2 , C 3 , C 9 , and C 11 -C 16 were observed, while the other carbons were almost the same when metabolite 5 was compared with the parent drug andrographolide, suggesting that the difference of metabolite 5 occurred at the side chain of lactone and ring A. The carbon signal of carbonyl shifted from 172.6 to 176.7 ppm, while the oxygen-linked carbon of C-15 shifted from 76.1 to 72.7 ppm. The changes in chemical shifts showed that the double bond at 12(13) of andrographolide changed to the 13(14) double bond, by which the double bond transferred from the outside to the inside of the lactone ring. In the heteronuclear multiple bond connectivity (HMBC) spectrum, the signal of H-15 (4.94, 2H) had peaks correlated with C-13 (131.3 ppm) and C-14 (151.7 ppm), indicating that a carboncarbon double bond is located at 13(14). The singlet of H-14 (7.73, H, br s) had a cross-peak with 55.8 (C-12), and H-12 (3.97, H, br d, Jϭ10.2 Hz) correlated with 131.3 (C-13), 151.7 (C-14), and 176.7 ppm (C-16). These correlated peaks showed that the sulfonate group is linked at C-12.The carbon signals of metabolite 5 at ring A differed from those of andrographolide. The...

Pharmacological Aspects of Andrographis paniculata on Health and Its Major Diterpenoid Constituent Andrographolide

“…Andrographolide metabolites are mainly identified as sulfonic acid adducts and sulfate compounds, as well as glucuronide conjugations. Ten metabolites of andrographolide as sulfonates, sulfate ester compounds, and andrographolide analogues were isolated from rat urine, feces, and the contents of the small intestine after the drug was orally administrated to rats, [54][55][56] while those metabolites isolated from human urine were as sulfates, cysteine S-conjugate, and glucuronide conjugates. 52,57) One of the metabolites, 14-deoxy-12(R)-sulfo-andrographolide (M-1 12R, Fig.…”

Diastereoisomeric ent‐Labdane Diterpenoids from Andrographis paniculata

“…2). The absolute configuration of 1 was established on the basis of the configurations of andrographolide and isoandrographolide, which were confirmed by X-ray diffraction [15] [16] and ORD studies [17] [18]. Considering the biogenetic pathway of these diterpenoids, the configurations of C(3), C(4), C(5), C(9), and C(10) of 1 were determined as (R), (R), (S), (S), and (R), respectively.…”

Nine New ent‐Labdane Diterpenoids from the Aerial Parts of Andrographis paniculata.

“…Again, positive Legal and Kedde color reactions [18] confirmed the unsaturated g-lactone moiety. The absolute configuration at C (15) could not yet be established [19] [20]. The absolute configuration at C (15) could not yet be established [19] [20].…”

“…Also isolated were nine known constituents, which could be identified by comparison of their physico-chemical and spectroscopic properties with published data: neoandrographolide (10) [7] [10] [12], 3,14-dideoxyandrographolide (11) [10] [12], andro-A C H T U N G T R E N N U N G grapholide (12) [9] [10], 14-deoxy-11,12-didehydroandrographolide (13) [8] [10] [12], 19-hydroxy-ent-labda-8(17),13-dien-15,16-olide (14) [17], 14-deoxyandrographolide (15) [10] [12], deoxyandrographiside (16) [10] [12], 14-deoxy-11,12-didehydroandrographiside (17) [10], and andrographiside (18) [10].…”

“…The IR spectrum of 7 showed the presence of OH groups (3415), a COOH function (1677), as confirmed by reaction with Bromocresol Green, and an exo-methylidene group (902 cm À1 ). Furthermore, the 3 J correlation between CH 2 (15) 6 was recrystallized from MeOH to afford 12 (56 g). The NMR spectroscopic data of 7 were very similar to those of 14-deoxyandrographolide (15) [10] [12], except that C(15) and C (16) were shifted upfield to d(C) 61.6 and 170.5, respectively.…”