Neolignan and lignan glycosides from branch bark of Davidia involucrata

Abstract

Two new neolignan glycosides, davidioside A (1) and davidioside B (2), have been isolated along with six known compounds from the branch bark of Davidia involucrata. Identification of their structures was achieved by 1D and 2D NMR experiments, including (1)H-(1)H COSY, NOESY, HMQC, and HMBC methods as well as FAB mass spectral data.

Three New Ring-A Modified Ursane Triterpenes from Davidia involucrata

“…D. involucrata is a deciduous relic tree species of the Tertiary period with important ecological, scientific, and horticultural values [1][2][3]. More than 30 components, including flavonoids, sterols, triterpenes, alkaloids, and tannins, etc., were identified from the aerial part of D. involucrata [4][5][6]. Our continuing efforts of the phytochemical study of this plant have led to the isolation of two new nor-ursane type triterpenoids with a five-membered A ring and a novel 2,3-seco-ursane triterpene, which were named davinvolunic acids A-C (compounds 1-3).…”

Five New Taraxerene-Type Triterpenes from the Branch Barks of Davidia involucrata

“…An initial and the only report of study on chemical components of D. involucrata besides our program appeared in 1989, which revealed the presence of sterols, tannins and triterpenes [4]. The branch barks of D. involucrata have been intensively studied in our previous work and were found containing diverse constituents including flavonoids, alkaloids, lignans, and phenols, among which were three alkaloids including vicosamide, strictosidinic acid and puimiloside, which were proposed to be the intermediate precursors between strictosamide and camptothecin [5][6][7][8][9][10][11][12]. Moreover, we have recently reported the identification of two novel 2-nor-ursane triterpenes having a unique five-membered A-ring from the water insoluble fraction of the branch barks of D. involucrata [13].…”

“…Our continuing work led to the isolation of another five novel triterpenoids, namely davinvolunols A-B (1-2) and davinvolunones A-C (3-5), together with a known taraxerene triterpene, myricadiol (6) [14][15][16], and four known triterpene esters, 3β-O-trans-p-coumaroyl-2α-hydroxy-urs-12-en-28-oic acid (7) [17][18][19], 3β-O-cis-p-coumaroyl-2α-hydroxy-urs-12-en-28-oic acid (8), 3β-O-trans-p-feruloyl-2α-hydroxy-urs-12-en-28-oic acid (9), 3β-O-cis-p-feruloyl-2α-hydroxy-urs-12-en-28-oic acid (10) [19] ( Figure 1). Compounds 1-3 feature a contracted five-membered A-ring, whereas 4-5 are highly oxidized.…”

Two New Lignans and Anti‐HBV Constituents from Illicium henryi

“…The CO C-atom signal at d(C) 172.6 and a Me signal at d(C) 21.1 suggested the presence of an AcO moiety in compound 1. Analysis of NMR spectra revealed that compound 1 was almost identical with dihydrodehydrodiconiferyl alcohol 9-O-b-dxylopyranoside (6) [9], except for the presence of the signals due to an AcO moiety. The cross-peak between HÀC(3'') and C(1''') (d(C) 172.6) observed in the HMBC spectrum indicated that the AcO group was linked to C(3'') ( Fig.).…”

“…The known compounds, threo-4,9,9'-trihydroxy-3, [12], (À)-dihydrodehydrodiconiferyl alcohol (4) [15], ficusal (5) [16], dihydrodehydrodiconiferyl alcohol 9-O-b-d-xylopyranoside (6) [9], dihydrodehydrodiconiferyl alcohol 9-O-a-l-rhamnopyranoside (7) [17], sakuraresinol (8) [13], and breynioside A (12) [20] were identified by comparison of their spectroscopic data with those reported.…”