Acide acétoxy-3βe oléanène-12(13) oïque-28βa

Roques, R.; Declercq, Jean‐Paul; Germain, G.

doi:10.1107/s0567740878008225

Cited by 8 publications

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“…On the whole the molecular geometry of hydrocarbon scaffolds of the ursolic acid (and its derivatives, including the ursane acid 1) [33] and oleanolic acid (and its derivatives, including the oleanand acid 2) [34] is the same. It is schematically depicted in Scheme 3.…”

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Oxidative lactonization of oleanane and ursane acids by treating with ozone

et al. 2015

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Features of process of oxidative lactonization of 3-oxooleanolic and 3-oxoursolic acids under treatment with ozone were established. The similarity of the processes consists in generation of 3-oxooleanolic or 3-oxoursolic 13β,28-lactones with 12-oxo or 12-hydroxy group. In the case of ursane derivative the generation exclusively of compounds with β-oriented 12-hydroxy group was observed, in the case of oleanane lactones prevailingly compounds with α-oriented 12-hydroxy group were obtained. The processes differ by the generation of the product of allylic oxidation, 3,11-dioxoursolic acid, or the isolation of the product of the lactone cycle opening with participation of the solvent, 3,12-dioxoolean-28-olic acid.Oleanolic and ursolic acids, belonging to triterpenoids of the series of β-and α-amirine, are widely spread in plants and exhibit various pharmacological properties [1, 2]. One of the directions of their modification is the oxyfunctionalization of cycles А, C, and E, leading to new bioactive compounds [3][4][5][6][7][8][9][10][11][12][13][14].One of the successful examples of oxidative functionalization of oleanolic acid that should be mentioned is the synthesis of 2-cyano-3,12-dioxo-olean-1 (2),9(11)-dien-28-olic acid (CDDO), possessing antiphlogistic, antitumor, antidiabetic, and antiangiogenic activity [15][16][17][18][19]. Methyl ester CDDO (methyl bardoxolone) passed the first phase of clinical trials as a drug for cancer treatment and second phase as a drug for treatment of chronical kidney diseases for patients suffering from sugar diabetes of the second type [5]. 12-Hydroxy-11-oxoolean-12-enes[3] exhibited a high cytotoxicity. 3β,12α-Dihydrooxyoleanolic 13β,28-olide is the key intermediate in the synthesis of endoteline of A receptors and a promising antidiabetic agent [8]. 2-Cyano-3-oxo-12α-fluorours-1-ene-13β,28-olide is effective against the cancer cells of pancreatic gland [20]. One of the products of oxidative transformation of ursolic acid in the presence of ruthenium porphyrins, 12β-hydroxyurs-11-ene-13β,28-olide, proved to be active against the cancer cells of human skin А431 [9, 10].Despite the fact that triterpenoids of the series of α-and β-amirine have very close structure and differ only by the position of a single methyl group in the E cycle, there is a significant difference in their oxidation processes. For example, the oxidation of methyl ursolate with ozone proceeds with generation of 12-oxo-11S,13R-oxetane fragment in the cycle С [21], whereas the oxidation of methyl oleanate leads to methyl 12-oxooleane [22]. Different courses of oxidation processes of triterpenoids belonging to the α-and β-amirine series with reagents like m-chloroperoxybenzoic acid and HCOOH-H 2 O 2 underlie their separation in the form of oxyderivatives, because in plants these metabolites often accompany each other [3,23,24].In continuation of our research on the oxidative transformations of vegetable terpenoids [25][26][27][28][29][30][31] we investigated in the present study the oxidation of С 12 =С 13 bond...

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Oxidative lactonization of oleanane and ursane acids by treating with ozone

et al. 2015

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“…Crystal data: (2), monoclinic form, monoclinic, space group P21, a = 15.368 (11), b = 11.586 (10), c = 7.831(6) A , f3 =…”

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Echinolactone A and B: isolation and structures of two novel lactones from the marine coelenterate Echinopora lamellosa

Sanduja¹,

Weinheimer²,

Alam³

et al. 1984

J. Chem. Soc., Chem. Commun.

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Two novel pentacyclic triterpenes were isolated from the marine coelenterate Echinopora lamellosa; their structures and absolute configuration (determined from spectroscopic and X-ray diffraction data) are reported.Marine invertebrates, particularly coelenterates, have been shown to contain a large number of novel compounds.* The extracts of one such coelenterate, Echinopora lainellosa (class Anthozoa, family Scleractinidae), collected from the waters of Korolevu, Fiji, was found to contain two novel pentacyclic triterpenes which have not so far been encountered in marine invertebrates. In this communication we report the isolation, structure elucidation, and absolute configuration of echinolactone A (1) and echinolactone B (2) from E. lamellosa.The propan-2-01 extract of the coelenterate upon concentration and lyophilization gave a residue, which after usual partitioning,2 gave a CHC13 extract. Flash chromatography3 followed by h.p.1.c. gave a group of fractions consisting of two compounds, which were then combined and separated by preparative t.1.c. to give (1) and (2).*Compound (1) crystallized from MeOH to give colourless needles, m.p. 245 "C, C32H4605 (calcd. 510.3345, found 510.3381).$ The i.r. spectrum of (1) showed the presence of an a,p-unsaturated ketone (1670 cm-l), an acetoxy group (1720 and 1265 cm-I), and a y-lactone (1770 cm-1) moiety. The 400 MHz 1H n.m.r.O spectrum of (1) showed the presence of

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“…It occurs both free and as simple esters in a wide variety of higher plants (De Mayo, 1959) and is the parent compound of innumerable oxygenated analogues (Connolly & Overton, 1972). It is thus surprising that while X-ray structure determinations have been carried out on a number of the more oxygenated analogues of fl-amyrin (Hoge & Nordman, 1974;Roques, Druet & Comeau, 1978;Roques, Declercq & Germain, 1978;Roques, Comeau, Forme, Kahn & Andre, 1977;Mak, Chiang & Chang, 1982;Kitagawa et al, 1982) the parent compound has not been so studied. Other relevant crystal structures that have been determined are those of simple mamyrin esters (a-amyrin differs from fl-amyrin only in the position of the C29 methyl group) and of methyl ursolate (mamyrin-28-carboxylate) (Grynpas & Lindley, 1979;Paton & Paul, 1979).…”

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“…The structure of fl:amyryl acetate is in general terms close to those already found for the more oxygenated analogues of the fl-amyrin series. Complete structural information is available for gymnemagenin (Hoge & Nordman, 1974), hederagenin (Roques, Druet & Comeau, 1978), 3fl-acetoxyolean-12(13)-en-28fl-oic acid (Roques, Declercq & Germain, 1978) Table 1; selected structural data are provided in Table 2 10-5-6 109.7 (5) 10-5-6-7 -64.0 5-6-7…”

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confidence: 99%