Secoiridoid glycosides

Secoiridoid glycosides Jasminum urophyllum SiOj CIS CHCI3 + MeOH + HjO MeOH + H2O Isolation 81... 

Schaufelberger, D. and Hostettmann, K., Analytical and preparative reversed-phase liquid chromatography of secoiridoid glycosides, J. Chromatogr., 346, 396, 1985. 

Iridoid and secoiridoid glycosides with modified functionalities... 

Some examples of plants that produce irirdoid or secoiridoid glycosides, and their medicinal uses, are summarized below. 

Oleuropein, a secoiridoid glycoside Fraxinus excelsior (ash tree), Olea europaea (olive tree) and Ligustrum obtusifolium from the family Oleaceae are the major sources of oleuropein. This compound has hypotensive. 

Gentianae radix (3) a major red-brown and a minor zone of secoiridoid glycosides —> gcntiopicroside Rf — 0.45) and Lswertiamarine directly below. 

Menyanthidis folium (6) three bright blue zones of the secoiridoid glycosides foliamenlhin, menthafolin, dihydrofoliamenthin in the Rf range 0.6-0.8 additional yellow-brown tlavonoid glycosides in the Rf range 0.2-0.5. 

Fig. 4 A Menyanthidis folium (3). shows in UV-254 nm live weak fluorescence-quenching zones of secoiridoide glycosides (R, 0.4/0.55/0.70), flavonol glycosides (R, 0.1) and aglycones...

Iridoids are monoterpene compounds characterized by a cyclopenta [c] pyranoid skeleton, also known as the iridane skeleton (cis-2-oxabicyclo-[4, 3, 0]-nonane). These are also found to occur in a variety of animal species. In a broad sense, it is acceptable to include in this group the secoiridoids, which arise from the latter by cleavage of the 7, 8 bond of the cyclopentane ring. This group (of about 500 known structures) chiefly comprises iridoid glycosides (>300), secoiridoid glycosides (>100), and non glycosidic compounds (>100). 

S. nervosa Wall. Ex DC is an annual, erect, branched, glabrous herb, distributed in north temperate Himalaya. Sweroside (7) and swertiamarin (60) and secoiridoid glycoside vegeloside (61) have been reported from this species [91]. 

Similarly, swertiamarin from S. angustifolia [92], swertiamarin (60) and sweroside (7), secoiridoid glycosides augustiamarin (62), augustioside (63) and eustomoside (64) from S. augustifolia [93], swertiamarin, sweroside (7) amarogentin B (65), amaroswerin (59) and... 

Iridoids and secoiridoid glycosides reported from different species of Gentiana are shown in table 2. 

The chief iridoids and secoiridoid glycosides, sweroside, swertiamarin and gentiopicroside are also reported from other species of Centaurium such as C. maritimaum, C. pulchellum, C. quintense, C. spicatum, and C. tenuiflorum [152],... 

Ray S, Majumder HK, Chakravarty AK et al. Amarogentin, a naturally occurring secoiridoid glycoside and a newly recognized inhibitor of topoisomerase I from Leishmania donovani. J Nad Prod 1996 59 27-29. 

Secoiridoid glycosides are monoterpenes that are derived from secologanin, their biosynthetic precursor. They represent the bitter principles of many plant families, especially in the Comales, Dipsacales and Gentianales orders. They may occur as esters with different acids, and especially with biphenylcarbonic acids, which enhance strongly their bitter taste. Plant containing these compounds are used in many herbal preparations for their stomachic properties. 

Monoterpenes, like triterpene glycosides, have been analysed in LC/MS by both TSP of CF-FAB ionisation. As secoiridoid glycosides occur mainly as monoglucosides, TSP is often the method of choice for their detection and identification. Thus, the bitter principles of various Gentianaceae species have efficiently been screened by this mode [22,23]. However, in certain cases LC/CF-FAB-MS was found to be essential for the screening of unknown larger secoiridoids. 

LC/UV analysis exhibited different peaks (5-8) with retention times less then 10 min (Fig. 7). Their UV spectra showed only one maximum around 240 nm that was characteristic for a chromophore containing an a, )-unsaturated ketone function, attributable to a secoiridoid glycoside(swertiamarin (5) (MW 374), kingiside (6) (MW 404), epi-kingiside (7) (MW 404) and sweroside (8) (MW 358)). A very... 

This example shows well the use of both LC/MS ionisation techniques for targeting unknowns. LC/TSP-MS indicated that compounds 8 and 10-13 had common sub-units (identical fragments (MW 358)), while CF-FAB allow the on-line molecular weight determination of all of these types of oligomers. The combination of both types of information has thus allowed the early recognition of this type of large secoiridoid glycosides. 

Fig. 8. LC/UV chromatogram of G. ottonis with UV spectra and main FSP/LC-MS ions of the major constituents. HPLC Column, RP-18 NovaPak (4 im, 150 x 3.9 mm i.d.) gradient, CH3CN-H2O (0.05% TFA) 5 95 ->65 35 in 50 min (1.0 ml/min). UV spectra of 14 and 16 were characteristic for flavones, while those of 15 and 17-19 were indicative of xanthones and those of 5 of a secoiridoid glycoside.

Ma, W. -G., Fuzzati, N., Wolfender, J. -L., Hostettmann, K. and Yang, C. (1994). Rhodenthoside A, a new type of acylated secoiridoid glycoside from Gentiana rhodentha. Helv, Chim. Acta 77,1660-1671. 

Haloui, M., L. Louedec, J.B. Michel, and B. Lyoussi. 2000. Experimental diuretic effects of Rosmarinus officinalis and Centaurium erythraea. J. Ethnopharmacol. 71(3) 465-472. Kumarasamy, Y, L. Nahar, P.J. Cox, M. Jaspars, and S.D. Sarker. 2003a. Bioactivity of secoiridoid glycosides from Centaurium erythraea. Phytomedicine 10(4) 344-347. 

Uesato, 1986). Randomization of label from [2- " C]MVA between C-3 and C-11 usually was observed in iridoid and secoiridoid glycosides and in indole alkaloids (Inouye and Uesato, 1986). 

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