Brevifoliol, a taxane from Taxus Brevifolia

Balza, Felipe; Tachibana, Sanro; Barrios, H.; Towers, G.H.N.

doi:10.1016/0031-9422(91)84218-h

Cited by 37 publications

(18 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…(1994) [42] sinharine Hofer et al (1992) [41] chemical synthesis Johnson et al (1994) [42] NMR UV IR MS degradation no calyculaglycoside A Rodríguez et al (1997) [43] isolation of related compounds, biogenetic considerations, and degradation [44] NMR UV IR CD MS no harrisonin Nakanishi et al (1976) [45] [47] isolation of related compounds and reevaluation Rodríguez and Crews (1994) [48] NMR IR MS no brevifoliol Tachibana et al (1991) [49] reisolation and reexamination Georg et al (1993) [50] NMR EA UV IR derivatization Hubbs and Heathcock (1999) [53] isoschizogamine Renner and Fritz (1965) [51] reisolation and 2D NMR spectroscopy Hµjícek et al (1998) [52] NMR EA IR derivatization no FR900148 Kuroda et al (1980) [54] reisolation and reexamination Yasuda and Sakane (1991) [55] NMR IR MS derivatization Corey and Kania (1998) [58] palominol Rodríguez et al (1990) [56] isolation of related compounds and comparison of spectra Shin and Fenical (1991) [57] NMR UV IR CD MS derivatization Trost and Harrington (2004) [60] (+)-amphidinolide A Kobayashi et al (1991) [59] chemical synthesis Trost and Harrington (2004) [60] NMR UV IR MS Grossman and Rasne (2001) …”

Section: The State Of Modern Structure Elucidationmentioning

confidence: 99%

Chasing Molecules That Were Never There: Misassigned Natural Products and the Role of Chemical Synthesis in Modern Structure Elucidation

2005

View full text Add to dashboard Cite

Over the course of the past half century, the structural elucidation of unknown natural products has undergone a tremendous revolution. Before World War II, a chemist would have relied almost exclusively on the art of chemical synthesis, primarily in the form of degradation and derivatization reactions, to develop and test structural hypotheses in a process that often took years to complete when grams of material were available. Today, a battery of advanced spectroscopic methods, such as multidimensional NMR spectroscopy and high-resolution mass spectrometry, not to mention X-ray crystallography, exist for the expeditious assignment of structures to highly complex molecules isolated from nature in milligram or sub-milligram quantities. In fact, it could be argued that the characterization of natural products has become a routine task, one which no longer even requires a reaction flask! This Review makes the case that imaginative detective work and chemical synthesis still have important roles to play in the process of solving nature's most intriguing molecular puzzles.

show abstract

Section: The State Of Modern Structure Elucidationmentioning

confidence: 99%

Chasing Molecules That Were Never There: Misassigned Natural Products and the Role of Chemical Synthesis in Modern Structure Elucidation

2005

View full text Add to dashboard Cite

show abstract

“…8 We optimized the isolation of brevifoliol from such extracts. An updated spectral characterization of brevifoliol, 1, is given in Tables S1 and S2 (Supporting Information).…”

Section: Resultsmentioning

confidence: 99%

“…The residue was purified by radial chromatography (2% MeOHCH2Cl2, EtOAc-Hex, 1:1) to give 78 mg (78%) of enone 8 as a white powder: mp 215-219°C, [R] 23 D -2.9°(c 1.0, CH2Cl2); IR (KBr) νmax 3570,2972,1753,1740,1716,1664,1599,1451,1372,1242,1087,1070,1024,959,824,807,720,668 (1H, br s), 5.50 (1H, br s), 6.25 (1H, d, J ) 10.7 Hz), 6.88 (1H, d, J ) 10.7 Hz), 7.43 (2H, t, J ) 7.5 Hz, Hm-Ph), 7.58 (1H, t, J ) 7.5 Hz, Hp-Ph), 7.91 (2H, br d, J ) 7.5 Hz, Ho-Ph, in a 4:1 ratio with δ 8.03), 8.03 (2H, br d, J ) 7.5 Hz, Ho-Ph); 13 C NMR (CDCl3, 75 MHz) δ 8. 8,12.5,14.0,26.6 (4 CH3,20.7,21.1,21.2 [3 CH3,], 27.5, 33.6 (2 CH2, C-2 + C-6), 39.0 (CH, C-3), 45.1 (C,49.6 (CH2,, 59.0 (C, C-1), 69. 5,70.1,74.0,77.2 (4 CH,75.2 (C,114.3 (CH2,, 128.8, 129.5 (2 CH, C-2′ + C-3′), 129.4 (C, C-1′), 133.5 (CH, C-4′), 145.0, 147.0 (2 C, C-4 + C-12), 163.6 (C, O2CPh), 163.9 (C,169.5,169.8,169.9 [3 C, (b) From NMO-TPAP Oxidation.…”

Section: -Acetyl-13-oxobrevifoliol (8) (A) From Pcc Oxidationmentioning

confidence: 99%

Characterization of an abeo-Taxane: Brevifoliol and Derivatives

et al. 2004

View full text Add to dashboard Cite

Brevifoliol is a natural diterpene isolated from Taxus baccata Nutt. A series of brevifoliol 1 derivatives, 2-8 and 10, were prepared for characterization and semisynthesis purposes and included the introduction of acetyl, Troc, and TES groups at C-5 and C-13. Derivatives 16-20 of 5-acetylbrevifoliol 2 were obtained via esterification with cinnamic acid, with both 2S-(-)- and 2R-(+)-3-phenyllactic acid, and with N-benzoyl-(2'R,3'S)-3'-phenylisoserine at C-13. Brevifoliol compounds 12, 13, and 15 with either 2S-(-)-phenyllactate moieties at C-5 and C-13 or an N-benzoyl-(2'R,3'S)-3'-phenylisoserinyl at C-13 were also prepared. An abeo-taxane structure for 1 was clearly defined from the (13)C NMR analysis of the 5-acetyl-13-oxo derivative 8 and from the conversion of 1 into 10, a conformationally restrained compound having a C-13, C-15 oxygen bridge. The biological activity of each of these derivatives is being studied.

show abstract

“…Brevifoliol was the first natural taxoid to be endowed with a 11(15 ! 1)abeo-taxane skeleton, which was initially assigned to the normal series [3] [4]. In a similar way, a number of taxoids whose basic structure were previously reported as derivatives of brevifoliol with the normal taxane skeleton, or by considering them as baccatin VI derivatives, have now been proposed to be rearranged 11(15 !…”

mentioning

confidence: 99%

abeo‐Taxane Diterpenoids from the Taiwanese Yew Taxus sumatrana

Wang

El‐Razek²,

Chen

et al. 2009

Chemistry & Biodiversity

View full text Add to dashboard Cite

Chemical investigation of the acetonic extract of the leaves and twigs of Taxus sumatrana (Taxaceae) led to the isolation of four new taxane diterpene esters, taiwantaxins A-D (1-4, resp.). Their structures were determined primarily on the basis of 1D- and 2D-NMR techniques as well as MS. Compound 1 is a rearranged taxane diterpenoid possessing an opened oxetane ring moiety containing C(4), C(5), and C(20). The metabolites 2 and 3 belong to a 5/6/6 taxene system having a rare five-membered gamma-lactone ring comprising C(8), C(9), C(10), and C(19). Compound 4 is an example of a taxane diterpene containing a 6/8/6 ring system with a tetrahydrofuran ring comprising C(2), C(3), C(4), and C(20). The 11(15-->1)abeo-taxane diterpenoids, taiwantaxins A-C (1-3, resp.) are lacking an O-bearing functionality at either C(13) or C(14). Compound 2 showed significant cytotoxic activity against human PC-3 tumor cells.

show abstract

Brevifoliol, a taxane from Taxus Brevifolia

Cited by 37 publications

References 5 publications

Chasing Molecules That Were Never There: Misassigned Natural Products and the Role of Chemical Synthesis in Modern Structure Elucidation

Chasing Molecules That Were Never There: Misassigned Natural Products and the Role of Chemical Synthesis in Modern Structure Elucidation

Characterization of an abeo-Taxane: Brevifoliol and Derivatives

abeo‐Taxane Diterpenoids from the Taiwanese Yew Taxus sumatrana

Contact Info

Product

Resources

About