Oxidative and reductive transformations of 11-keto-β-boswellic acid

Csuk, René; Barthel-Niesen, Anja; Ströhl, Dieter; Kluge, Ralph; Wagner, Christoph; Al‐Harrasi, Ahmed

doi:10.1016/j.tet.2015.01.062

Cited by 10 publications

(15 citation statements)

References 44 publications

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“…Rings D and E are cis fused along the C17-C18 bond along with the axially oriented carboxylic acid functionalities at C14 and C17. The bond dimensions are similar to those found in structurally related compounds (Csuk et al, 2015;Awang et al, 2009).…”

Section: Structural Commentarysupporting

confidence: 78%

Crystal structure and Hirshfeld surface analysis of 3-oxours-12-ene-27a,28-dioic acid (quafrinoic acid)

et al. 2017

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The title compound, C 30 H 44 O 5 , is a pentacyclic triterpene isolated from the Cameroonian medicinal plant Nauclea Pobeguinii and known as quafrinoic acid. The molecule is composed of five fused six-membered rings, four of which adopt a chair conformation and one a half-chair conformation. Intramolecular C-HÁ Á ÁO hydrogen-bond interactions exist, which generate S6 and S8 rings. In the crystal, molecules are linked by pairs of O-HÁ Á ÁO hydrogen bonds, linking R 2 2 (8) rings into chains running parallel to the a axis; these chains are further connected into layers parallel to the ab plane by C-HÁ Á ÁO hydrogen bonds. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from HÁ Á ÁH (79.4%) and OÁ Á ÁH (20.4%) interactions.

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Section: Structural Commentarysupporting

confidence: 78%

Crystal structure and Hirshfeld surface analysis of 3-oxours-12-ene-27a,28-dioic acid (quafrinoic acid)

et al. 2017

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“…20 Frankincense was bought from different commercial suppliers in bulk quantities, and the SRB assays were performed as previously reported 15,16 . 3-O-Acetyl-11-keto--boswellic acid (1, AKBA) was isolated following a modified Jauch's procedure 21 , and (3, 4) 3-hydroxy-11-oxo-urs-12-en-24-oic acid (= 11-keto-boswellic acid, 2, KBA) was prepared as reported.…”

Section: Methodsmentioning

confidence: 99%

“…Several studies revealed these pentacyclic triterpenoids to have antitumor activity [10][11][12] . While the cytotoxicity of 1 or 2 is low, derivatives of AKBA or KBA showed significant higher activity 5,11,[13][14][15][16][17][18][19][20] .…”

Section: Introductionmentioning

confidence: 99%

β-11-Keto-boswellic acid derived amides: synthesis and cytotoxicity

et al. 2017

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The aim of this study was to prepare 11-keto-β-boswellic acid derivatives modified at C-24 and to evaluate their in vitro cytotoxicity. Acetyl-11-keto-β-boswellic acid (AKBA) was isolated from frankincense and transformed into 11-keto-β-boswellic acid (KBA). Both compounds served as starting materials for the synthesis of several amides or hydrazides. The derivatives were fully characterized, and their cytotoxicity was evaluated in vitro using sulforhodamine B (SRB) assays employing two human tumor cell lines (A2780 and MCF7) as well as nonmalignant mouse fibroblasts (NIH 3T3). Nearly all of the compounds were more cytotoxic than their parent compounds. The highest cytotoxicity was observed for (3 α, 4 β) 3-acetyloxy-N-(3- aminopropyl)-11-oxo-urs-12-en-24-amide (15) and (3 α, 4 β) 3-acetyloxy-N-[4-(3-aminopropyl)piperazin-1-yl]- propyl-11-oxo-urs-12-en-24-amide (16) and the ovarian carcinoma cell line A2780. These compounds showed EC50 = 1.0-1.7 µM while being significantly less toxic for the mouse fibroblasts NIH 3T3 (EC50 = 9.3-16.3µM). Thus, compounds 15 and 16 have good antitumor effects and may serve as starting points for developing potential and selective antitumor agents

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“…Thus, KBA was transformed (Scheme 2) into the corresponding benzylester 10 [25,37]. Glycosylation of 10 with 2,3,4,6-tetra-O-acetyl-a-D-glucopyranosyl trichloracetimidate or 2,3,4,6-tetra-O-acetyl-a-D-galactopyranosyl trichloracetimidate [38,39] in the presence of BF 3 $Et 2 O [40] at À25 C gave a 52% yield of 11 and 48% of 12, respectively.…”

Section: Chemistrymentioning

confidence: 99%