Unusual bromination of tetrahydro-(–)-α-santonins and new santonin isomers: X-ray crystal and molecular structure of 2β,14-dibromo-4α,5β,6β,11βH-tetrahydrosantonin

Abstract

Die Tetrahydrosantonine (I) werden mit 2 Moläquiv. Brom in Trichlormethan bei 0°C zu den Dibromiden (II) halogeniert, die zu Alloisosantonin (IIIa) und Isosantonin (IIIb) dehydrobromiert werden.

Secondary Metabolites of Plants from the Genus Saussurea: Chemistry and Biological Activity

“…a-Santonin, for example, is well-known for its cytotoxic, antiinflammatory [204], and antitumor [205] properties. From a SAR point of view, endo/exo-cross-dienones such as gerin (84), 7a-hydroxygerin (85), 8-O-deacetylgerin (86), and encelin (79) are often more reactive against biological nucleophiles than regular cross-dienones [204]. Compared to compounds 84 -86, encelin (79), indeed, showed the strongest antitumor activity.…”

ChemInform Abstract: Secondary Metabolites of Plants from the Genus Saussurea: Chemistry and Biological Activity

“…Sesquiterpenoids with 1,4-dien-3-one moieties often exhibit significant cytotoxicities [201 -203]. a-Santonin, for example, is well-known for its cytotoxic, antiinflammatory [204], and antitumor [205] properties. From a SAR point of view, endo/exo-cross-dienones such as gerin (84), 7a-hydroxygerin (85), 8-O-deacetylgerin (86), and encelin (79) are often more reactive against biological nucleophiles than regular cross-dienones [204].…”

Terpenoids and Sterols from Saussurea cauloptera

“…a-Santonin, for example, is well-known for its cytotoxic, anti-inflammatory [27], and antitumor [28] properties. From a structure -activity relationship (SAR) point of view, endo/exo-cross-dienones such as 1 -4 are often more reactive against biological nucleophiles than regular cross-dienones [27]. In addition, the a-methylidene-g-lactone unit seems to be important for biological activity as well [28], many analogous compounds with this group showing antibacterial [29] [30] or antitumor [31 -33] properties.…”

“…Sesquiterpenoids with 1,4-dien-3-one units often exhibit significant cytotoxicity [24 -26]. a-Santonin, for example, is well-known for its cytotoxic, anti-inflammatory [27], and antitumor [28] properties. From a structure -activity relationship (SAR) point of view, endo/exo-cross-dienones such as 1 -4 are often more reactive against biological nucleophiles than regular cross-dienones [27].…”

“…From the petroleum-ethersoluble part of the EtOH extract of the whole plant of S. cauloptera, compounds 1 -27 were isolated, and their structures were determined. There were i) eight sesquiterpenoids, gerin (1) [3], 7a-hydroxygerin (2) 1 ), 8-O-deacetylgerin (3), encelin (4) [4], 11,12-dihydrocostol (5) [5] [6], 7a-hydroxycostol (6) [7], eudesma-4(14),11(13)-diene7a,8a,12-triol (7) [8], and spathulenol (8) [9]; ii) one diterpenoid, 3a-hydroxy-ent-labda-8 (20), 13-dien-16,15-olide (9), which is the first ent-labdane diterpenoid 2 ) from this genus; iii) eleven triterpenoids, b-amyrin (10) [11], a-amyrin (11) [11], 20a,21a-epoxytaraxastan-3b-ol (12) [12], taraxasterol (13) [11], taraxast-20(30)-ene-3b,21a-diol (14) [12], ptiloepoxide (15) [12], taraxast-20-ene-3b,22a-diol (16) [13], taraxast-20-en-3b, 30-diol (17) [12] [14], 3b-hydroxytaraxast-20-en-22-one (18) [12], lupeol (19) [11], and 3b-hydroxy-30-nor-lupan-20-one (20) [15]; iv) six sterols, b-sitosterol (21) [16], stigmast-5-ene-3b,7a-diol (22) [17], stigmast-4-en-3-one (24) [16], 22-dihydrospinasterol (25) [18] [19], and ergosta-6,22-dien-3b,5a,8a-triol (26) [20]; and vi) arctigenin (27) [21...…”