New Bicyclic Taxane Diterpenoids from Taxus sumatrana

Abstract

The chemical constituents of Taxus have been extensively investigated worldwide as a result of the discovery of paclitaxel with its remarkable anti-cancer activity.1,2) Although more than 450 taxane diterpenes have been discovered to date, the biogenesis of paclitaxel and taxoids is still unclear. Verticillene is considered to be the most likely intermediate between geranylgeranyl pyrophosphate and the taxane diterpenes. [3][4][5] In continuation of our research on the taxane diterpenoids of endemic Taxus species, [6][7][8][9][10][11][12][13][14] a phytochemical study of T. sumatrana was carried out. A chromatographic fractionation of an acetone extract of the leaves and twigs of the plant has resulted in the isolation of three new taxane diterpenes, named tasumatrols M (1), N (2) and O (3). In addition, two known taxane, 7-deacetylcanadensene (4) and 2a,7b,13a-triacetoxy-5a,9a-dihydroxy-2(3→20) abeotaxa-4(20),11-dien-10-one were also isolated. The structures of 1-3 were established on the basis of spectroscopic analyses, especially 1-and 2D NMR.The HR-ESI-MS of 1 revealed a quasi-molecular ion peak at m/z 575.2466 [MϩNa] ϩ consistent with the molecular formula C 28 H 40 O 11 and nine degrees of unsaturation. The IR spectrum displayed absorption bands diagnostic of hydroxyl, double bonds and ester groups. Both showed HMBC correlation with C-7, C-8 and C-9 at d C 62.6, 128.2 and 141.1. The relative configuration of 1 was determined through comparing 1 H-NMR data and the coupling constants with those of 7-deacetylcanadensene (4) 17) and from its NOESY spectrum that showed correlations between H-10/H-7; H-1/Me-16; Me-17/H-2 and H-13/Me-16 (Fig. 1). Finally, acetylation of 1 provided compound 5 identical with a product derived from acetylation of 4. Hence, the structure of 1 was established and named tasumatrol M.The HR-ESI-MS of 2 revealed the molecular formula C 28 H 38 O 11 (two protons less than 1), as derived from a quasimolecular ion at m/z 573.2310 ([MϩNa] ϩ ). The 13 C-NMR of 2 (Table 2) Investigation of an acetone extract of the leaves and twigs of Taxus sumatrana has resulted in the isolation of two new bicyclic taxoids, tasumatrols M (1), and N (2) and a new baccatin III derivative, tasumatrol O (3) together with the previous known 7-deacetylcanadensene (4) and 2a a,7b b,13a a-triacetoxy-5a a,9a a-dihydroxy-2(3→20) abeotaxa-4(20),11-dien-10-one. The structures of these taxanes were established on the basis of spectroscopic analyses, especially 1-and 2D NMR, and chemical derivatization.

Highly Oxygenated Cyclobutane Ring in Biomolecules: Insights into Structure and Activity

“…[103]. A neoclerodane diterpenoid, chamaedroxide (95), containing an oxetane ring was found in Teucrium chamaedrys [104], and the aerial parts of Teucrium salviastrum contain diterpene teucroxide (96) and teusandrin E (97, structures are shown in Figure 8 and activities are shown in Table 3) [105]. 98), a steroid with rearranged A/B rings and an unusual bufadienolide with a cycloheptatriene B ring, was isolated from the toad Bufo bufo gargarizans [106].…”

Highly Oxygenated Cyclobutane Ring in Biomolecules: Insights into Structure and Activity

“…The genus Taxus is known for containing over 450 taxane diterpenes, many of which have an oxetane ring. An acetone extract from the leaves and twigs of Taxus sumatrana resulted in the isolation of bicyclic taxoids tasumatrol Y (87) [96] and tasumatrol V (88) The genus Taxus is known for containing over 450 taxane diterpenes, many of which have an oxetane ring. An acetone extract from the leaves and twigs of Taxus sumatrana resulted in the isolation of bicyclic taxoids tasumatrol Y (87) [96] and tasumatrol V (88) [97].…”

KERAGAMAN GENETIK Taxus SumatranaDARI POPULASI ALAM DI JAMBI MENGGUNAKAN PENANDA RAPD

“…Sumber biofarmasi merupakan salah satu potensi dan manfaatnya yang paling banyak dibutuhkan. Dalam bidang biofarmasi taxus dikenal sebagai tumbuhan yang mengandung taxane diterpenoid atau paclitaxel (taxol) yang bersifat anti kanker (Farr, 2008;Malik et al, 2011;Shen et al, 2002Shen et al, , 2005. Pengobatan seorang pasien kanker membutuhkan taxol sebanyak 2 -2,5 gr kebutuhan tersebut setara dengan 6-8 pohon taxus (Malik et al, 2011).…”