New Minor Taxane Derivatives from the Needles of Taxus canadensis

Abstract

Seven minor taxane derivatives were isolated for the first time from the needles of Taxus canadensis. Four of these natural taxanes are O-glycosylated (1-4), with 4 being the only reported taxane with a glucose on ring C, and two have a dimethylamino-C-5 side chain (5 and 6). An unusual double bond at C-5(6) has been identified in taxane 7.

Novel Taxa-4(20),12-diene and 2(3→20)Abeotaxane from Needles ofTaxus canadensis

“…[3][4][5][6] T. canadensis, an evergreen shrub distributed in North America, especially in the Quebec region of Canada, is one of the most extensively studied yews and more than 100 new taxanes have been reported. [7][8][9] As a continuation of our phytochemical study on T. canadensis, [10][11][12][13] we investigated the needles and isolated a new 6/8/6-membered taxane with a rare C-12(13)-double bond (1) and a new rearranged 2(3!20)abeotaxane (2) (Fig. 1).…”

Four new epoxy taxanes from needles of Taxus cuspidata (Taxaceae)

“…Extensive study on the plants of Taxus genus has resulted in the isolation of more than 400 taxanes in the past two decades [4][5][6]. Although many taxoids have been isolated to date, new taxoids continue to be discovered [7][8][9], and some of them could become precursors of paclitaxel and its analogs and some of them showed new activity [10]. Taxus cuspidata is one of the earliest and most extensively studied species [11,12].…”

A New Metabolite with a New Substitution Pattern from the Seeds of the Chinese Yew, Taxus mairei

“…The chemical shift of HÀC(9) at d(H) 5.05 suggested that the remaining AcO group was attached to C(9), although we did not observe the long-range correlation from HÀC(9) to the corresponding carbonyl Catom. The signal at d(H) 3.01, which exhibited assigned to HÀC (10). Thus, the structure of 1 was characterized as 5a,15-dihydroxy7b,9a-diacetoxy-11(15 !…”