24S-Chirality of 24-alkylsterols possessing a Δ25-double bond from Polypodium formosanum

Akihisa, Toshihiro; Takahashi, S.; Sahashi, Norio; Kokke, W. C. M. C.; Tamura, Toshitake

doi:10.1016/0031-9422(92)80289-q

Cited by 9 publications

(3 citation statements)

References 21 publications

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“…Cyclomargenol (4) and cyclomargenone (5) are compounds already reported in the literature [10][11][12][13][14]26]; however, the spectroscopic data are not described completely for these two metabolites. For this reason, the present work assignment of NMR data on the basis of 1D and 2D experiments (Table 1S and 2S, Supporting Information) was completed.…”

Section: Resultsmentioning

confidence: 96%

Cycloartanes from Krameria pauciflora and Their In Vitro PLA2, COX-1, and COX-2 Enzyme Inhibitory Activities

et al. 2012

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Krameria pauciflora is a species belonging to the Krameriaceae family. It has been used to treat inflammatory disorders in folkloric Mexican medicine; however, chemistry and pharmacological studies have not been carried out on this species. In this work, from the dichloromethane root extract of K. pauciflora, five cycloartane-type triterpenoids were isolated: cyclomargenyl-3-O-β-caffeoyl ester (1), cyclomargenyl-3-O-β-feruloyl ester (2), cyclomargenyl-3-O-β-coumaroyl ester (3), cyclomargenol (4, polysthicol), and cyclomargenone (5). Additionally, the lignane 6'-methoxyrataniaphenol was isolated. To the best of our knowledge, compounds 1-3 are new natural products, whereas compounds 4 and 5 are isolated for the first time in the Krameria genus and the Krameriaceae family. The structures of all of these compounds were established by 1D and 2D NMR spectroscopy including ¹H, ¹³C, DEPT, COSY, HSQC, and HMBC experiments, as well as by EI mass spectrometry. There is an incomplete previous report about the spectroscopic data of compounds 4 and 5. However, in this work, a complete and unambiguous assignation has been realized. Due to the traditional use of this plant and other species from this genus, such as K. lappacea, cycloartanes isolated herein were evaluated by their inhibition of phospholipase A₂, cyclooxygenase-1, and cyclooxygenase-2 enzymes. Cyclomargenyl-3-O-β-caffeoyl ester (1) showed inhibition of phospholipase A₂, cyclooxygenase-1, and cyclooxygenase-2 target enzymes for nonsteroidal anti-inflammatory drugs. Both cyclooxygenases were inhibited by cyclomargenol (4); however, cyclomargenyl-3-O-β-feruloyl ester (2) showed inhibition only on cyclooxygenase-1.

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Section: Resultsmentioning

confidence: 96%

Cycloartanes from Krameria pauciflora and Their In Vitro PLA2, COX-1, and COX-2 Enzyme Inhibitory Activities

et al. 2012

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“…Test Compounds. Thirty compounds are natural products isolated from various plants: 2 , 3 , 17 , 18 , 35 , and 37 from rice bran, 1 and 6 from Cucurbitaceae plants, 4 , 5 , 32 , 33 , and 34 from Gramineae, Solanaceae, and other plants, 7 from Polypodium formosanum , 8 and 10 from Bryonia dioica , 9 , 11 − 13 , and 38 from chrysanthemum flowers, 30 from Cimicifuga simplex , and 39 − 41 , 43 − 46 , and 48 from Musa sapientum . − Nine test compounds are biotransformation products of cycloartanes by the fungus Glomerella fusarioides : 14 and 15 from 3 ; 21 from 2 ; and 23 − 28 from 21 . Seven test compounds were semisynthesized from naturally occurring compounds: 29 and 31 , 42 , 47 , 16 and 36 , and 22 …”

Section: Methodsmentioning

confidence: 99%

“…28 Compound 19 was obtained from 21 by reduction with LiAlH4 followed by the usual workup 24 (26), 393 (19), 365 (6), 313 (12), 297 (10), 286 (28), 271 (19), 259 (10), 69 (100). (20), 365 (7), 339 (7), 297 (10), 286 (22), 271 (13), 203 (29), 69 (100).…”

Section: Methodsmentioning

confidence: 99%

Cancer Chemopreventive Effects of Cycloartane-Type and Related Triterpenoids in in Vitro and in Vivo Models

et al. 2007

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Forty-eight natural and semisynthetic cycloartane-type and related triterpenoids have been evaluated for their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells as a primary screening test for anti-tumor promoters. In addition, these triterpenoids have been tested for their inhibitory effects on activation of (+/-)-(E)-methtyl-2-[(E)-hydroxyimino]-5-nitro-6-methoxy-3-hexemide (NOR 1), a nitric oxide (NO) donor, as a primary screening test for anti-tumor initiators. All of the compounds tested exhibited inhibitory effects on both EBV-EA and NOR 1 activation. Six of these compounds having a C-24 hydroxylated side chain, viz., (24R)-cycloart-25-ene-3beta,24-diol (9), (24R)-cycloartane-3beta,24,25-triol (11), (24S)-cycloartane-3beta,24,25-triol (12), (24xi)-24-methylcycloartane-3beta,24,241-triol (14), (24xi)-241-methoxy-24-methylcycloartane-3beta,24-diol (15), and (24xi)-24,25-dihydroxycycloartan-3-one (27), showed higher inhibitory effects than the others tested on both EBV-EA (IC50 values of 6.1-7.4 nM) and NOR 1 activation. Furthermore, compounds 14 and 15 exhibited inhibitory effects on skin tumor promotion in an in vivo two-stage mouse skin carcinogenesis test using 7,12-dimethylbenz[a]anthracene (DMBA) as an initiator and TPA as a promoter.

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Akihisa

1997

Analysis of Sterols

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24S-Chirality of 24-alkylsterols possessing a Δ25-double bond from Polypodium formosanum

Cited by 9 publications

References 21 publications

Cycloartanes from Krameria pauciflora and Their In Vitro PLA2, COX-1, and COX-2 Enzyme Inhibitory Activities

Cycloartanes from Krameria pauciflora and Their In Vitro PLA2, COX-1, and COX-2 Enzyme Inhibitory Activities

Cancer Chemopreventive Effects of Cycloartane-Type and Related Triterpenoids in in Vitro and in Vivo Models

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