7,8beta-dihydroponasterone A, a new phytoecdysteroid from the needles of the Japanese Yew, Taxus cuspidata

Shi, Qing; Dong, Ming; Huo, Chang Hong; Su, Xiao Hui; Li, Xing; Yamada, Teiko; Kiyota, Hiromasa

doi:10.1590/s0103-50532007000500032

Cited by 4 publications

(3 citation statements)

References 11 publications

(13 reference statements)

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“…Its 1 Н and 13 С NMR spectra are identical to those of the natural 7,8β-dihydroponasterone А that have been lately isolated from the needles of STEREOSPECIFIC FORMATION OF 7,8β-DIHYDROANALOGS Japanise yew Taxus cuspidata (Taxaceae) as an amorphous substance with the specifi c optical rotation [α] D 22 +76° (с 0.20, MeOH) [11]. The 7,8β-dihydroponasterone А that we wave synthesized for the fi rst time proved to be a solid substance (mp 107-109°С) with the specifi c optical rotation [α] D 22 -22.2° (с 0.17, MeOH).…”

Section: Methodsmentioning

confidence: 77%

Stereospecific formation of 7,8β-dihydroanalogs at the reduction of ponasterone acetonide with lithium in liquid ammonia

2011

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The reduction of ponasterone А diacetonide with lithium in liquid ammonia stereospecifi cally led to 7,8β-dihydroanalogs of 5α-and 5β-epimers of ponasterone А and 7,8β-dihydro-6α-hydroxy derivative. 7,8β-Dihydroponasterone А, phytoecdysteroid from the needles of Japanise yew Taxus cuspidata, and its 5α-epimer were synthesized.The reduction of the double bond in the B ring of ecdysteroids resulting in their 7,8-dihydroanalogs provide a possibility to obtain compounds with a new biological action [1]. However the reduction of the sterically diffi cultly accessible Δ 7 -bond in ecdysteroids failed to be selective under common conditions of the catalytic hydrogenation due to numerous side reactions [1][2][3]. Recently a stereoselective catalytic hydrogenation of Δ 7 -6-ketosteroids was reported on palladium in the presence of sodium nitrite [4] or sodium methylate [5] providing the availability of ecdysteroids 7,8α-analogs.In natural sterines the hydrogen atom at the chiral С 8 carbon has a β-confi guration, and the B and C rings exist in the trans-junction. The conjugated steroid 8-enones are known to react with lithium in liquid ammonia (under Birch reaction conditions) with a high selectivity to be reduced into the corresponding saturated ketones with the formation of a 8β-chiral center [6].We established that ponasterone А diacetonide (I) in the reaction with lithium in liquid ammonia was converted into a mixture of 5β-(IIа) and 5α-(IIb) epimeric ketones and 5βН,8βН,6α-alcohol III, the product of further reduction of saturated ketone IIa (see the scheme).The structure of alcohol III was established from the analysis of the 1D and 2D 1 Н and 13 С NMR spectra. Compared to the spectrum of the initial compound I where the signal of atom С 6 appears in the region 203.0 ppm, the С 6 signal of alcohol III is shifted to the region of 67.6 ppm. The reduction of the Δ 7(8) -double bond is indicated by the shift of signals of atoms С 7 and С 8 from the weak fi eld to the region 39.8 and 34.0 ppm. In the HSQC spectrum they correlate with the signals of protons Н 2 С 7 (δ 1.34 and 1.74 ppm) and НС 8 (1.55 ppm). The correlation in the NOESY spectrum between the protons of the group Н 3 С 19 (δ 0.99 ppm) and НС 5 (δ 1.89 ppm) confi rms the β-orientation of the proton at the atom С 5 , the correlation between the protons НС 5 and НС 6 (δ 4.20 ppm) indicates the β-orientation of the latter. The proton НС 6 is coupled also with protons Н 3 С 19 and НС 8 (HMBS spectrum). The β-orientation of the proton НС 8 corresponds to its correlation with the protons Н 3 С 18 (δ 0.91 ppm).Thus compound III is a 6α-alcohol where the proton at the newly formed chiral center С 8 has the β-confi gurqation, and the proton at С 5 conserves the β-confi guration of the initial ecdysteroid.We failed to separate the mixture of diacetonides of 5β/α-epimeric ketones IIa, IIb, but their 20,22-monoacetonides IVa, IVb were isolated by the column chromatography on silica gel. The structure of compounds IVa, IVb was established applying 1D and 2D 1 Н and 13 С N...

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Section: Methodsmentioning

confidence: 77%

Stereospecific formation of 7,8β-dihydroanalogs at the reduction of ponasterone acetonide with lithium in liquid ammonia

2011

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“…From the Taxaceae family, a conducted literature survey indicates that three new ecdysteroids have been reported. The new ecdysteroids are 7,8 β -dihydroponasterone A ( 214 ), isolated from the plant Taxus cuspidate 148 , ponasterone A 20,22- p -hydroxybenzylidene acetal ( 215 ), and ponasterone A 20,22-acetonide ( 216 ), isolated from the plant Taxus canadensis Marsh 149 .…”

Section: New Naturally Occurring Phytoecdysteroids Reported Since 1999mentioning

confidence: 99%

The phytochemical, biological, and medicinal attributes of phytoecdysteroids: An updated review

Das¹,

Mishra

Bishayee³

et al. 2021

Acta Pharmaceutica Sinica B

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The phytoecdysteroids (PEs) comprise a large group of biologically-active plant steroids, which have structures similar to those of insect-molting hormones. PEs are distributed in plants as secondary metabolites that offer protection against phytophagus (plant-eating) insects. When insects consume the plants containing these chemicals, they promptly molt and undergo metabolic destruction; the insects eventually die. Chemically, ecdysteroids are a group of polyhydroxylated ketosteroids that are structurally similar to androgens. The carbon skeleton of ecdysteroids is termed as cyclopentanoperhydro-phenanthrene with a β -side chain at carbon-17. The essential characteristics of ecdysteroids are a cis -(5 β -H) junction of rings A and B, a 7-en-6-one chromophore, and a trans -(14 α -OH) junction of rings C and D. Plants only synthesize PEs from mevalonic acid in the mevalonate pathway of the plant cell using acetyl-CoA as a precursor; the most common PE is 20-hydroxyecdysone. So far, over 400 PEs have been identified and reported, and a compilation of 166 PEs originating from 1998 has been previously reviewed. In the present review, we have summarized 212 new PEs reported between 1999 and 2019. We have also critically analyzed the biological, pharmacological, and medicinal properties of PEs to understand the full impact of these phytoconstituents in health and disease.

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“…T. cuspidata is one of the most extensively investigated yews, and more than 120 taxanes have been isolated from it [1][2][3][4][5][6]. As a continuation of our research on plants from the Taxus genus, we reinvestigated the leaves of T. cuspidata collected at Sendai, Japan [7][8][9][10][11][12][13][14][15], and isolated three new taxanes (l " Fig. 1 [10,11,16]).…”

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confidence: 99%

A Novel Taxane 13-Glucoside and Other Taxanes from the Leaves ofTaxus cuspidata

Dong

Cong

et al. 2010

Planta Med

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Three new taxanes, 2 α,9 α,10 β-triacetoxy-13 α-( β-D-glucopyranosyloxy)taxa-4(20),11-dien-5 α-ol, 5 α,10 β,13 α-triacetoxytax-11-ene-2 α,7 β,9 α,20-tetraol, and 5 α,10 β,13 β-triacetoxy-2 α,7 β-dihydroxy-2(3→20) abeotaxa-4(20),11-dien-9-one, were isolated from the leaves of the Japanese yew, Taxus cuspidata. Compound 1 is the first example of a taxane with 13-glycosidic linkage.

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7,8beta-dihydroponasterone A, a new phytoecdysteroid from the needles of the Japanese Yew, Taxus cuspidata

Abstract: O novo ecdisteróide 7,8β-di-hidroponasterona A e a ponasterona A, foram isolados a partir do extrato metanólico das agulhas do teixo japonês Taxus cuspidata. As estruturas foram elucidadas por meios espectroscópicos, nomeadamente, RMN

Cited by 4 publications

References 11 publications

Stereospecific formation of 7,8β-dihydroanalogs at the reduction of ponasterone acetonide with lithium in liquid ammonia

Stereospecific formation of 7,8β-dihydroanalogs at the reduction of ponasterone acetonide with lithium in liquid ammonia

The phytochemical, biological, and medicinal attributes of phytoecdysteroids: An updated review

A Novel Taxane 13-Glucoside and Other Taxanes from the Leaves ofTaxus cuspidata

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