Some Taxane Derivatives from the Heartwood of Taxus Mairei

Five Taxane derivatives were isolated from Taxus mairei. Their structures were determined by spectroscopic methods and their physical constants were identical with the literature values. These are Taxa-4(20), 11-diene-2α, 5α, 7β-tetrol-5α, 7β, 10β-triacetate-2α-α-methylbutyrate(I); Taxa-4(20), 11-diene-2α, 5α, 9α, 10β, 13β-pentol-2α, 9α, 10β, 13α-tetraacetate-5α-cinnamate(II);Taxa-4(20), 11-diene-5α, 7β, 9α, 10β, 13α-pentol-pentaacetate(III); 7β-acetate-O-taxinine A(IV), 1β-hydroxy-baccatin-I(V).     

Taxayuntin I from Taxus Yunnanensis

Taxayuntin I, a new 11 (15->l)abeotaxane, was isolated from the leaves and stems of Taxus yunnanensis. Its structure was elucidated on the basis of spectroscopic data.     

New 6/8/6‐Taxanes Isolated from the Heartwood of Taxus cuspidata

Two new natural taxanes were isolated from the heartwood of Taxus cuspidata. The structures were established as rel‐(2α,5α,7β,9α,10β,12α)‐7,9‐bis(acetyloxy)‐2‐(benzoyloxy)‐11,12‐epoxy‐1,5‐dihydroxy‐10‐[(hydroxyacetyl)oxy]tax‐4(20)‐en‐13‐one ( 1 ), and (2α,5α,10β,14β)‐taxa‐4(20),11‐diene‐2,5,10,14‐tetrol 2‐acetate ( 2 ) on the basis of spectroscopic analysis.     

Tri‐ and Bicyclic Taxoids from the Taiwanese Yew Taxus sumatrana

Five new taxoids, including a new 2(3→20)‐abeo‐taxane with a 6/10/6‐membered ring system and four 3,8‐seco‐taxanes having a 6/12‐membered ring system, were isolated from an acetone extract of the leaves and twigs of the Taiwanese yew (Taxus sumatrana, Taxaceae). The structures were established as 2α,7β,10α‐triacetoxy‐5α‐hydroxy‐2(3→20)‐abeo‐taxa‐4(20),11‐dien‐9,13‐dione ( 1 ), (3E,8E)‐2α,9,10β, 13α,20‐pentaacetoxy‐7β‐hydroxy‐3,8‐secotaxa‐3,8,11‐trien‐5‐one ( 2 ), (3E,8E)‐2α,9,10β,13α,20‐pentaacetoxy‐5α,7β‐dihydroxy‐3,8‐secotaxa‐3,8,11‐triene ( 3 ), (3E,8E)‐9,10β,13α‐triacetoxy‐2α,7β,20‐trihydroxy‐5α‐[(2E)‐cinnamoyloxy]‐3,8‐secotaxa‐3,8,11‐triene ( 4 ), and (3E,8E)‐2α,5α,7β,9,10β,13α‐hexaacetoxy‐20‐hydroxy‐3,8‐secotaxa‐3,8,11‐triene ( 5 ), respectively, on the basis 1D‐ and 2D‐NMR spectral analyses. The in vitro cytotoxic activity of compounds 1 – 5 against four human tumor cell lines, including HeLa (cervical epitheloid), WiDr (colon), Daoy (medulloblastoma), and Hep2 (liver carcinoma) tumor cells was evaluated. Whereas compounds 1 – 3 were inactive, the novel taxanes 4 and 5 showed significant cytotoxicity.     

Taxane Diterpenoids from the Root Bark of Taiwanese Yew Taxus Mairei

Nineteen compounds including taxumairol R (1) , taxinine M (2) , taxacin (3) , paclitaxel (4) , 10‐deacetyltaxol A (5) , 10‐deacetyl‐7‐epi‐taxol (6) , 7‐epi‐taxol (7) , taxol C, 10‐deacetyltaxol C, 7β‐xylosyl‐10‐deacetyltaxol (8) , taxamairin A (9) , taxinine A, 14β‐hydroxytaxusin (10) , 5α‐hydroxy‐7β,9α,10β, 13α‐tetraacetoxy‐4(20), 11‐taxadiene, 1‐dehydroxybaccatin‐VI, 1β‐dehydroxybaccatin‐IV, baccatin IV, baccatin VI and ponasterone A have been isolated and identified from the root bark of Taxus mairei. Among them, compound 1 was a new taxoid and compounds 11 and 7β‐xylosyl‐10‐deacetyltaxol pentaacetate were new derivatives prepared from 14β‐hydroxytaxusin (10) and 8 , respectively. Their structures and assignment were established on the basis of 2D‐NMR analysis and chemical methods.     

8β-hydroxyeremophil-7(11)-ene-12,8α(4β,6α)-diolide分子的晶体结构

8β-hydroxyeremophil-7(11)-ene-12,8α(4β,6α)-diolide was isolated from the Ligularia intermedia and char- acterized by MS, multi NMR and X-ray single crystal diffraction. Its crystal structure was determined as in a orthorhombic type, with space group P212121 with a=6.8519(5), b=10.7191(8), c=18.5942(14) oA, V =1365.67(18) oA3, Z=4, and the calculated density is 1.354 mg/m3. F(000)=592, μ=0.101 mm-1.     

Specific oxidation of C-14 oxygenated 4(20),11-taxadienes by microbial transformation

Three C-14 oxygenated taxanes, 2α,5α,10β,14β-tetraacetoxytaxa-4(20),11-diene (1), 2α,5α,10β-triacetoxy-14β-(2-methylbutyryloxy)taxa-4(20),11-diene (2), and yunanaxane (3), major products of callus cultures of Taxus spp., were regio- and stereoselectively hydroxylated at the 7β position by a fungus, Absidia coerulea IFO 4011. Intriguingly, when 1 was co-administered with β-cyclodextrin and incubated with the fungus cell cultures, three other compounds 5α,9α,10β,13α-tetraacetoxytaxa-4(20),11-dien-14β-ol (7), 5α,9α,10β,13α-tetraacetoxytaxa-4(20),11-dien-1β-ol (8) and 5α,9α,10β,13α-tetraacetoxy-11(15→1) abeotaxa-4(20),11-dien-15-ol (9) were obtained.     

Tasumatrols P – T,Five New Taxoids from Taxus sumatrana

The phytochemical investigation of the more polar fractions from the leaves and twigs of Taxus sumatrana (Taxaceae) afforded five new taxane diterpene esters, tasumatrols P–T ( 1 – 5 ) possessing an 11(15→1),11(10→9)‐diabeotaxane skeleton. Compounds 1, 4 , and 5 contain an α‐hydroxy group at C(14), while 3 has no OH group at either C(13) or C(14). Compound 2 is a natural 4,5‐acetonide derivative, while 4 has an unusual spiro‐connected 2‐hydroxy‐2‐phenyl‐1,3‐dioxolane ring. Ten known taxoids, were also isolated in the course of the chromatographic fractionation. Five additional new O‐acetyl derivatives 3a, 4a, 4b, 5a , and 5b were prepared from the taxanes 3 – 5 . The structures of all new compounds were established on the basis of their spectroscopic analyses. Compound 1 showed mild cytotoxic activity against human Hela and Daoy tumor cells.     

Studies on the Constituents of Ganoderma Lucidum

The methanolic extract of fruit bodies of cultivated Ganoderma lucidum was separated by silica gel column chromatography and preparative thin-layer chromatography to give ten compounds. On the basis of spectral analysis, chemical procedures and gas chromatography, d-mannitol (1), ergosta-7, 22-dien-3β-yl palmitate (2), ergosterol (3), ergosta-7, 22-dien-3β-ol (4), 5α-lanosta-7,9(11),24-trien-3β,26-diol (5), ergosterol peroxide (6), 24,25,26-trihydroxy-5α-lanosta-7,9(11)-dien-3-one (7), 5α-lanosta-7,9(11)-dien-3β,24,25,26-tetraol (8) and 8,9-epoxyergosta-5,22-dien-3β,15-diol (9) were identified. Among these compounds, 8,9-epoxyergosta-5,22-dien-3β,15-diol was first separated from Ganoderma lucidum.     

A new eremophilane-type sesquiterpene from Ligularia virgaurea

A new eremophilane-type sesquiterpene,1α,8β,10β-trihydroxy-6β-(2-methylacryloyl)oxyeremophil-7(11)-en-8α,12-olide, was isolated from the roots of Ligularia virgaurea.Its structure was established on the basis of various spectroscopic analyses, including the 1D,2D NMR techniques and HR-ESI-MS.     

Sesquiterpenes from the Roots of Ligularia duciformis

Two new sesquiterpenes named liguducin-A ( 1 ) and -B ( 4 ) were isolated from a Chinese medicinal plant, the dried roots of Ligularia duciformis, together with four known sesquiterpenes, 4α, 10β-dihydroxy-1β,5α-H-guai-6-ene ( 2 ), 4α-hydroxy-1β,5α,11α-H-guai-9-en-12,8α-olide ( 3 ), 1β-hydroxyeudesm-4,11-dien-3-one ( 5 ) and 1β,6α-dihydroxyeudesm-4(15)-ene ( 6 ). On the basis of the spectral evidence, their structures were determined.     

A novel 3,8-seco-taxane metabolite from the seeds of the Chinese yew, Taxus mairei

The structure of a novel 3,8-seco-bicyclic taxanoid metabolite, isolated from the methanol extract of seeds of the Chinese yew, Taxus mairei, was established as (11αH)-3,8-seco-taxa-3E,7E,12(18)-triene-2α,6α,9β-triol (1) on the basis of spectral analysis including ¹H NMR, ¹³C NMR, HMQC, HMBC, NOESY and HR-FABMS.     

Die Struktur der Drevogenine. 2. Mitteilung Struktur von Drevogenin P. Glykoside und Aglykone, 278. Mitteilung

Drevogenin A was converted in several steps (acetylation, hydrogenation, dehydration, hydrogenation, the haloform reaction and energetic alkaline hydrolysis) into 3β, 11α, 12β-trihydroxy-5α-etianic acid, which could be characterised by its crystalline methyl ester ( 15 ) and its tri-O-acetyl methyl ester ( 16 ). The same acid was obtained by partial synthesis starting from hecogenin. Taking into consideration earlier results [1], the structure of drevogenin P is proved to be 3β, 11α, 12β, 14β-tetrahydroxy-20-oxo-Δ⁵-pregnene ( 7 ). Energetic hydrolysis of dihydro-3-O-acetyldrevogenin A gave a mixture of 17αH- and 17βH-desacyl-kondurangogenin A, which were obtained in crystalline form after separation by chromatography. The only difference between the basic structures of the drevogenins and kondurangogenin A is the presence of a double bond in the 5-position in the former.     

Canataxpropellane, a novel taxane with a unique polycyclic carbon skeleton (tricyclotaxane) from the needles of Taxus canadensis

A novel taxane with an unprecedented 5/5/4/6/6/6-membered hexacyclic skeleton containing [3.3.2]propellane was isolated from the needles of the Canadian yew, Taxus canadensis. The structure was established as 2α,10β-diacetoxy-5α,9α,20α-trihydroxy-3α,11α;4α,12α;14α,20-tricyclotaxan-13-one (1), which exists as two conformational isomers on the basis of spectroscopic analysis. This compound would be biogenetically derived from a normal 6/8/6-taxane by the intramolecular aldol reaction and [2+2] cycloaddition.     

New ent-kaurane-type diterpenoids from Isodon nervosus

Two new ent-kaurane-type diterpenoids,6β,7β,13α-trihydroxy-1α-acetoxy-7α,20-epoxy-ent-kaur-16-en-15-one（1）and 15β- hydroxy-6,7-seco-6,11β：6,20-diepoxy-1α,7-olide-ent-kaur-16-ene（2）were isolated from the Isodon nervosus,and the structures were elucidated by spectroscopic analysis.     

Pulchellin C and inuchinenolide C from Inula caspica

The pseudoguaianolide inuchinenolide C and the eudesmanolide pulchellin C have been isolated for the first time from the flower heads and leaves ofInula caspica Blume, and their spatial structures have been established by an x-ray structural experiment as 2α,6β-diacetoxy-6α-hydroxy-1α,7α(H),8β,10β(H)-pseudoguai-11(13)-en-8,12-olide and 2α,3β-dihydroxy-5β,7α,8α(H)-eudesma-4(15),11(13)-dien-8,12-olide, respectively.     

Leucoxol,a new diterpenoid from acacia leucophloea. X-ray structure determination

From $\text{Acacia leucophloea}$ (Roxb.) Willd. (Mimosaceae) the new diterpenoid 11α, 16-epoxy-1β, 15$\text{R}$-dihydroxy-isopimar-8(14)-ene (leucoxol) has been isolated. Its structure was determined by X-ray diffraction analysis.     

Diterpenoide Drüsenfarbstoffe aus Labiaten: 11 Coleone und Royleanone aus Coleus carnosus HASSK

Diterpenoid Leaf-Gland Pigments: 11 Coleons and Royleanones from Coleus carnosus HASSK . The above mentioned plant has been investigated for its leaf-gland pigments. The following diterpenoids have been isolated (listed according to their elution from Sephadex LH-20, SiO₂ and polyamide; in parentheses the yield of each product in g/kg dried leafs): royleanone ( 1 )/6,7-dehydroroyleanone ( 2 ) (0.004, as a mixture); 7α-acetyloxyroyleanone ( 3 , 0.009); a novel dimeric diterpene of hitherto unknown structure (0.03); horminone ( 4 , 0.08); 6β-hydroxyroyleanone ( 5 , 0.04, new as a natural product); 7α-acetyloxy-6β-hydroxyroyleanone ( 6 , 5.45); 6β, 7α-dihydroxyroyleanone ( 7 , 1.20); 7α-acetyloxy-6β, 20-dihydroxyroyleanone ( 8 , 0.046, a novel compound); coleon U ( 9 , 1.32); coleon V ( 10 , 13.84); carnosolone (6α, 11, 12-trihydroxy-6,20-epoxymethano-abieta-8, 11, 13-trien-7-one ( 11 ), 1.25, a novel compound). Therefore, this plant is one of the richest one in royleanones and coleons so far investigated by us (pure crystalline compounds 2,3%, estimated total amount > 3% of dry weight). Among the isolated compounds carnosolone ( 11 ) is of special interest being the first of a group of colourless diterpenoids from Coleus- and Plectranthus- species turning blue on TLC. Its oxydation product 12 is one of the rare 4-acyl-ortho-quinones having high reactivity and characteristic spectral properties.     

青蒿素生物合成的研究II. 前体[15-^2H]-和[15-^3H]-青蒿酸的 化学合成

青蒿酸甲酯(5)用NBS溴化产生的溴化物,经NaBD~3CN或NaBD~4氘解,生成[15-^2H]-青蒿酸甲酯(6),其结构由MS,^1H,^2H和^1^3C的NMR确定。(6)经水解生成[15-^2H]-青蒿酸(4),用同样方法以NaB^3H~4为氘化试剂与溴化物反应,合成了[15-^3H]-青蒿酸(1)。     

A New Jatrophane Diterpenoid Ester from Euphorbia turczaninowii

A new jatrophane diterpenoid ester （2S, 3S, 4R, 5R, 7S, 8R, 13R, 15R） - 3, 5, 7, 8, 15- pentaacetoxy-9, 14-dioxojatropha-6（17）, 11E-diene was isolated from the whole plant of Euphorbia turczaninowii Kar. ＆ Kit.. Its structure was characterized by spectral analysis and confurmed by X-ray crystallographic analysis.