Studies on the Constituents of Gardenia Species. III. New Iridoid Glycosides from the Leaves of Gardenia jasminoides cv. fortuneana HARA

Abstract

We have reported the isolation of 13 new terpenoids from Gardeniae Fructus [the fruit of Gardenia jasminoides ELLIS (Rubiaceae)], known as the Shan-zhi-zi (in Chinese) herbal drug, and it has been used for its antiphlogistic, diuretic, and cholagogue effects. 1,2) In the course of further studies on the constituents of Gardenia species, we have now examined the iridoid constituents from the leaves of G. jasminoides cv. fortuneana HARA. This plant does not bear medicinal fruit, and there is no report, so far as we know, on the constituents of this plant. This paper describes the structural elucidation and identification of two new iridoid glycosides (1, 2), isolated along with six known (3-8) and three artifact (9-11) iridoids from this plant. The known iridoid glycosides were identified as monotropein methyl ester (ϭgalioside, 3), [3][4][5] gardenoside (4), [4][5][6] deacetylasperulosidic acid methyl ester (5), [7][8][9] scandoside methyl ester (6), 9-11) geniposide (7) 6,12) and ixoroside (8), 13) respectively, by direct comparison with authentic samples and/or by comparison of various spectral and chemical data with those reported in the literature. Inouye et al. reported the following biosynthetic sequences: 7→5→3 and 7→6→4, that is, 7 was a biosynthetic precursor of both 3 and 4.14) To our knowledge, this is the first example of co-occurrence of 3 and 4 in Gardenia species.Compound 1 was obtained as an amorphous powder, [a] D Ϫ43.4°(MeOH). The molecular formula of 1, C 17 H 24 O 11 , was confirmed by high-resolution (HR)-FAB-MS. In the 1 Hand 13 C-NMR spectra of 1, signal patterns were similar to those of 6-deoxycatalpol, which also has a 7, 8-epoxide, 15) . From the above data, the structure of 1 was elucidated as shown in the chart and termed 7b,8b-epoxy-8a-dihydrogeniposide. Compound 1 was isolated from a natural source for the first time, although a partially acetylated derivative of 1 has been synthesized from 7.11) To our knowledge, this is the first report of an iridoid glycoside containing a 7,8-epoxide function from Gardenia species.Compound 2 .07 (1H, m)] in 2 was evidently coupled with H-9 (d H 2.72), which appeared as a double double doublet. The NOE difference experiment showed that irradiation at H-9 resulted in NOE enhancements at H-5 and H-8 (d H 3.07). There was also NOE enhancement between H-1 and H-10 B . Consequently, compound 2 was revealed to be the epimer at C-8 of apodantheroside, 16) and the structure of 2 was determined to be 8-epiapodantheroside.Compound 9 was obtained as an amorphous powder, [a] D Ϫ114.1°(MeOH). The molecular formula of 9, C 18 H 26 O 11 , was confirmed by HR-FAB-MS. The 1 H-and 13 C-NMR spectra of 9, exhibited signal patterns very similar to those of 3, except for the presence of signals due to a methoxyl group [d H 3.27 (3H, s), d C 51.8]. The 13 C-NMR signal at C-8 of 9 was shifted by ϩ6.3 ppm (d C 92.4) in comparison with that of 3, suggesting that the methoxyl group is located at the 8- Aoba-ku, Sendai, Miyagi 981-8558, Japan. Received May 21, 2003; acc...

Melanogenesis Inhibitory Activities of Iridoid-, Hemiterpene-, and Fatty Acid-glycosides from the Fruits of Morinda citrifolia (Noni)

“…In the 1 13 C NMR spectrum of were very similar to those of 6-O-methyl deacetylasperulosidic acid methyl ester 16) , except that the absence of an ester methoxy signal at C-11, suggesting that possesses the structure, 6-O-methyl deacetylasperulosidic acid. However, compound exhibited the 1 16) . These differences in chemical shift for H-1 and H-9 signals, and in the coupling constant for H-1 doublet signal, indicated that the relative stereochemistry and the dihedral angle between H-1 and H-9 in could be different from those of 6-Omethyl deacetylasperulosidic acid methyl ester.…”

“…The 1 H NMR spectrum displayed signals at d H 7.38 (1H, s), corresponding to an enol ether system conjugated with a carboxyl group, and at d H 5.84 (1H, br s), due to a sp 2 methine proton of a double bond in the five-membered ring, as found in various iridoid glycosides [7][8][9][15][16][17] . In the 1 13 C NMR spectrum of were very similar to those of 6-O-methyl deacetylasperulosidic acid methyl ester 16) , except that the absence of an ester methoxy signal at C-11, suggesting that possesses the structure, 6-O-methyl deacetylasperulosidic acid. However, compound exhibited the 1 16) .…”

Isolation and purification of iridoid glycosides from Gardenia jasminoides Ellis by isocratic reversed-phase two-dimensional preparative high-performance liquid chromatography with column switch technology

“…The fruits of Gardenia jasminoides Ellis (Rubiaceae) (Chinese herbal name is Zhi Zi) has been used for the remedy for hepatic pain due to cirrhosis, abdominal pain due to dysentery, anti-phlogistics, diuretic, laxative, choleretic, and homeostatic purposes in the treatment of trauma by external application [1]. The major effective constituents of Gardenia fruits are iridoid glycosides such as geniposide, gardenoside, shanzhiside, scandoside methyl ester, deacetyl-asperulosidic acid methyl ester and genipin-1-␤-d-gentiobioside [2][3][4][5][6][7][8]. These compounds may be responsible for the biological activities of this drug [9][10][11][12][13][14] and their rapid and accurate purification is of great significance in the quality control of this natural drug and its formulations.…”

Neuritogenesis of Herbal Geniposide-Related Compounds in PC12h Cells

“…fortuneana HARA. 10) Loganin (S-5) and 7-ketologanin (S-6) were obtained from the leaves of Lonicera caerulea var.…”