Two new ent-kaurane diterpenoids from Isodon excisoides

Two new ent-kaurane diterpenoids taihangexcisoidesin A and B （1 and 2）, were isolated from the EtOAc extract of the leaves of lsodon excisoides. Their structures were determined on the basis of spectroscopic methods.

ent-Kaurane diterpenoids from the plant Wedelia trilobata

Four new ent-kaurane diterpenoids,namely,3α-tigloyloxypterokaurene L_(3)(1),ent-17-hydroxy-kaura-9(11),15-dien-19-oic acid(2),and wedelobatins A(3)and B(4),together with 11 known ent-kaurane diterpenoids(5-15),were isolated from the ethanol extract of Wedelia trilobata.All the structures of 1-15 were elucidated on the basis of spectroscopic studies.

Isolation and Crystal Structure of Ent-kaurane Diterpenes from Rubus corchorifolius L. f.

In this study, ent-Kaurane-3β,16β,17-trioi （1） and ent-kaurane-2a,16β,17-triol （2）, were isolated from the leaves ofRubus corchorifolius L. f. Their structures were elucidated based on extensive spectroscopic analysis. NMR experiments identified the two compounds and X-ray crystallographic analysis confirmed their crystal structures. The crystal of 1 belongs to monoclinic with space group P21 and a = 10.7641（3）, b = 7.2789（3）, c = 11.7862（4） A, β = 95.275（3）°, V = 919.55（6） A3, Z = 2, C20H34O4, Mr = 322.49 g/mol, Dc = 1.230 g/m3, F（000） = 376, 2 = 1.54178 A,μ = 0.661 mm-1, R = 0.0319, and wR = 0.0811 for 10889 observed reflections （I〉 2σ（I））. The crystal of 2 is classified as orthorhombic with space group P212121 and a = 10.7641（3）, b = 12.72224（19）, c = 21.3929（3） A, V= 1748.94（4） A3, Z= 4, C20H3404, Mr = 322.47, De = 1.225 Mg/m3 F（000） = 712, λ = 1.54184 A,μ = 0.625 mm-1, R = 0.0303 and wR = 0.0759 for 10470 observed reflections （1〉 2σ（I））. Meanwhile, the compound revealed low inhibitory activities toward HepG2, MCF-7, and SCG-7901 cells.

Two New ent-Kaurane Diterpenoids from Isodon xerophilus

Two new ent-kaurane diterpenoids, xerophilusin E (1) and xerophilusin F (2), were isolated from the leaves of Isodon xerophilus. Their structures were determined as 3, 20: 7, 20-diepoxy-ent-kaur-16-en-15-one and 7 beta, 14 beta, 20 (R)-trihydroxy-11 beta-acetoxy-7,20-cyclo-ent-kaur-16-en-6, 15-dione, respectively, by spectral methods and X-ray crystallographic analysis.

Two new ent-kaurane diterpenoids from Isodon henryi

Two new ent-kaurane diterpenoids, minheryins H （1） and I （2）, were isolated from the leaves of Isodon henryi. Their structures were elucidated by means of spectroscopic analysis, including 2D NMR spectra.

Isorosthornins A-C,new ent-kaurane diterpenoids from Isodon rosthornii

Three new ent-kauranoids,isorosthornins A-C(1-3),and a new natural product,dihydroponicidin(4),together with five known ones were isolated from the aerial parts of Isodon rosthornii.The structures were determined by means of extensive spectroscopic analysis.All diterpenoids isolated were evaluated for their cytotoxicity against HL-60,SMMC-7721,A-549,MCF-7,and SW480 cell lines,and compounds 5 and 7 showed significant inhibitory effects on all cell lines.

ent-Kaurane Diterpenoids from Isodon eriocalyx var. laxiflorat

Four new ent-kaurane diterpenoids, 6fl,13ct,15fl-trihydroxy-16-ene-3a,20-epoxy-ent-kaur- 1,7-dione （1）, 6-hydroxy-3a,20-epoxy-5（6）-ene-ent-kaur-l,7,15-trione （2）, 6-hydroxy-15fl-acetoxy-3a,20-epoxy-16]3,17-epoxy- 5（6）-ene-ent-kaur-l,7-dione （3）, 3ct,17-dihydroxy-15（16）-ene-ent-kaur-7-one （4）, along with four known com- pounds 5--8 were isolated from the leaves oflsodon eriocalyx var. laxiflora. The structures were elucidated by ex- tensive spectroscopic methods （IR, UV, MS and NMR）. The cytotoxic activities of these compounds were evaluated by MTT assay. Compound 8 showed moderate inhibitory effects on HL-60, SMMC-7721, MCF-7 and SW-480 cell lines.

Scopariusols L–T, nine new ent-kaurane diterpenoids isolated from Isodon scoparius

Nine new ent-kaurane diterpenoids, named scopariusols L–T(1–9), were isolated from the aerial parts of Isodon scoparius. Their structures were characterized mainly by analyzing the NMR and HR-ESI-MS data, and the absolute configuration of 1 was determined by single-crystal X-ray diffraction. Compound 1 was active against five human tumor cell lines(HL-60, SMMC-7721, A-549, MCF-7, and SW-480), and it also inhibited NO production in LPS-stimulated RAW264.7 cells, with an IC50 value of 0.6 μmol·L-1.

Two new ent-kaurane diterpenoids from the aerial parts of Isodon excisoides

Two new ent-kaurane diterpenoids, ent-7α,14β-dihydroxykaur-16-en-15-one-20-oic acid （1） and 1,7α,12β,14β-tetrahydroxy-1,10-seco-ent-kaur-10,16-dien-15-one （2）, together with six known ones （3-8）, were isolated from the EtOAc extract of the aerial parts of lsodon excisoides. Their structures were elucidated on the basis of 1D NMR and 2D NMR analyses as well as HR-ESI-MS experiments.

New ent-kaurane diterpenes with chiral epoxyangelate moieties from Wedelia prostrata

Four new ent-kaurane diterpenes with chiral epoxyangelate moieties, (2′R,3′R)-3 a- (2′,3′-epoxyangeloyloxy)-kaur-16-en-19-oic acid (1), (2′S,3′S)-3 a- (2′,3′-epoxyangeloyloxy)-kaur-16-en-19-oic acid (2), (2′S,3′R)-3 a- (2',3'-epoxyangeloyloxy)-kaur-16-en-19-oic acid (3) and (2′R,3′S)-3α- (2′,3'-epoxyangeloyloxy)-kaur-16-en-19-oic acid (4), along with eight known diterpenes (5-12), were isolated from Wedelia prostrata. The absolute configurations of the new structures were determined by X-ray crystallography,ECD calculations and chemical methods. All compounds were evaluated for their cytotoxicity activities on human HepG-2 cells,with IC_(50) values of 11.72 ±0.22 μmol/L to 54.75±1.12 μmol/L.

Fimbrialtols K–M, highly functionalized ent-kaurane diterpenoids from traditional Chinese plant Flickingeria fimbriata(B1.) Hawkes

Three new ent-kaurane diterpenoids fimbrialtols K–M（3–5） with highly substituted functionalities were isolated from the extract of Flickingeria fimbriata（B1.） Hawkes. The structures of these new compounds were determined by NMR and HR-ESIMS. The relative configurations of these compounds were determined by analysis of NOESY correlations. The absolute configurations of these new compounds were established by CD methods together with considering the biosynthetic pathway. Compounds 3 and4 contain a cinnamic carboxyl group, whereas compound 5 possesses a benzoic carboxyl group representing the first report in more than known 600 ent-kaurane diterpenoids.

Ent-Kauran-16β,17-diol碳信号的修正及其意义

作者针对文献关于 ent- kauran- 16 β,17- diol( )碳信号指认有误的问题 ,用化学合成方法和 2 D-NMR技术对 的结构进行全面分析和论证 ,首次归属了每个氢质子的信号 ,并再次证实其结构中的 C- 1、C- 7和 C- 14互为颠倒 ,该研究对 ent-

New diterpenoids from Isodon excisoides

Two new ent-kaurane diterpenoids,taihangexcisoidesin C(1) and its acetonide,taihangexcisoidesin D(2) were isolated from the leaves of Isodon excisoides.Their structures were determined by 1D and 2D spectroscopic analysis.

A new Kaurane Derivative from Aralia Fargesii

A new ent-kaurane diterpene was isolated from the rhizome of Aralia fargesii. On the basis of chemical and spectral evidences, its structure was established as 16 alpha-hydroxy-17-isovaleroyloxy-ent-kauran-19-oic acid.

Four new diterpenoids from Isodon eriocalyx var.laxiflora

Four new diterpenoids,laxiflorins S-V(1-4),bearing four different types,and one known compound,laxiflorin O(5),were isolated from Isodon eriocalyx var.laxiflora.Compound 1 was the first example of ent-kauranoids bearing a unique C_(24) carbon framework and compound 4 was the first example of 3,4-seco-ent-abietane diterpenoids from the Isodon genus.Their structures were determined by spectroscopic methods(UV,IR,MS,NMR).

Three New Diterpenoids from Isodon Eriocalyx

Three new diterpenoids, eriocalyxins C-E, were isolated from Isodon eriocalyx. Their structures were elucidated as 66-hydroxy- 15β-acetoxy-3α, 20-epoxy-16β, 17-epoxy-ent-kaur-1,7-dione, 1α, 7β-dihydroxy-6β, 15β-diacetoxy-7, 20-epoxy-ent-kaur-16-ene, and 15β-acetoxy-1, 6-dioxo-6, 7-seco-ent-kaur-2, 16-dien-7, 20-olide by means of spectroscopic methods, including two-dimensional NMR techniques.