Echinocystic acid

Full papers on the crystal structures of echinocystic acid diacetate bromo-lactone and papyrogenin have appeared. The structure of 3/3,16)3-... 

Codonopsis lanceolata (Sieb. et Zucc.) Trautv. Yang Lu (Bellflower) (whole plant) Apigenin, luteolin, alpha-spinasterol, stigmastenol, oleanolic acid, echinocystic acid, albigenic acid.48 Treat lung abscesses, stimulate milk flow, treat amenorrhea. 

Echinocystic acid (Cochalic acid) 128 Sapogenin from Echinocystis spp., Albizzia spp. 0.2 EBV, HeLa [16,30,37,43,140-142]... 

However, a saponin mixture, an unusual constituent of Baccharis genus, in which echinocystic acid, Fig. (69) is the major aglycone, has been found to be the main active principle of this plant. 

Time studies with Heliantims amuiiis indicate the progressive oxidation of /j-amyrin (100) to echinocystic acid (lOl). The enzyme involved in the cyclization of 2,3 22,23-bisoxidosqualene to a-onocerin (102) has been partially purif.ed. ... 

From the fruits of Gleditsia japonica, which have been used in Japanese and Chinese folk medicine as a diuretic and expectorant, seven saponins (gleditsiasaponins B, C, Dj, D2, E, G and I) had been isolated. The structural elucidation of these saponins have been carried out by the chemical degradations, enzymatic hydrolysis and C-NMR spectra, and characterized as 3, 28-0-bisglycosides of echinocystic acid acylated with monoterpene carboxylic acid [46-49]. 

Scheme 7. Proposed mechanism for transformation of cochalic acid to echinocystic acid.

Compound 2 was obtained as white amorphous powder, m.p. 280-284°C, [a]o -23.68 (MeOH, c 0.046). Positive ion FAB-MS provided a molecular ion m/z 1336, suggesting a molecular formula of C63H100O30, which was consistent with the result of elemental analysis (Found C, 53.33% H, 7.72% Cald C, 53.35%, H, 7.75% for C63H,oo03o.9/2H20). Its IR, H and CNMR spectra due to aglycone part were almost identical with those of 1, which suggested that compound 2 was also an echinocystic acid 3, 28-bidesmoside. 

Acid hydrolysis of compound 2 afforded echinocystic acid la, as well as glucuronic acid, arabinose, xylose, rhamnose and apiose. While on alkaline hydrolysis of 2, the prosapogenin lb was obtained. They were identified by direct comparison (PC and HRTLC) with authentic samples. 

In summary, microbial hydroxylation of p-amyrin and oleanolic acids may lead to new hydroxylations mainly in positions -7p, -15a but also frequently in other positions -lip, -11a, -2a, -29, -30, -13p, -2ip, -16a, -23, -24, -ip, -6p, and -7a (in order of priority, see Figure 28.28). With already hydroxylated olean derivatives such as echinocystic acid, phytolaccagenin, maslinic acid, or glycyrrhetinic acid as substrates, the corresponding complementary positions can be hydroxylated, obtaining a wide combinatorial variety of new multihydroxy derivatives, which should be difficult to achieve by classical chemical means and, potentially possess new or increased biological activities. Several of them have been previously isolated in plants as natural products. A summary of these results and yields is presented in Table 28.2. 

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