New 11(15-->1)abeotaxane, 11(15-->1),11(10-->9)bisabeotaxane and 3,11-cyclotaxanes from Taxus yunnanensis

Chemical examination of the seeds of Chinese yew, Taxus yunnanensis Cheng et L. K. Fu resulted in the isolation of an 11(15-->1)abeotaxane, an 11(15-->1), 11(10-->9)bisabeotaxane and two 3,11-cyclotaxanes. The structures of these new taxoids were established as 13alpha-acetoxy-5alpha-cinnamoyloxy-11(15-->1)abeotaxa-4(20),11-diene-9alpha,10beta,15-triol (1), 20-acetoxy-2alpha-benzoyloxy-4alpha, 5alpha, 7beta, 9alpha, 13alpha-pentahydroxy-11(15-->1), 11(10-->9) bisabeotax-11-eno-10,15-lactone (2), 2alpha,10beta-diacetoxy-5alpha-cinnamoyloxy-9alpha-hydroxy-3,11 -cyclotax-4(20)-en-13-one (3) and 10beta-acetoxy-2alpha,5alpha,9alpha-trihydroxy-3,11-cyclotax-4(20)-en-13-one (4) on the basis of spectral analyses.     

Taxane diterpenoids from Taxus yunnanensis and Taxus cuspidata

Chemical examination of the seeds of the Chinese yew, Taxus runnanensis Cheng et L. K. Fu and the Japanese yew, Taxus cuspidata Sieb et Zucc, resulted in the isolation of four taxane diterpenoids. The structures of these taxoids were established as (12alpha)-2alpha-acetoxy-5alpha,9alpha, 10beta-trihydroxy-3,11-cyclotax-4(20)-en-13-one; 2alpha,7beta,13alpha-triacetoxy-5alpha, 9alpha-dihydroxy-2(3-->20)abeotaxa-4(20),11-dien-10-one; 9alpha,10beta-diacetoxy-5alpha-cinnamoyloxytaxa- 4(20),11-dien-13alpha-ol and the known 2alpha,7beta,9alpha,10beta,13-pentaacetoxytax a-4(20),12-diene-5alpha,11beta-diol on the basis of spectral analysis.     

Taxanes with C-5-amino-side chains from the needles of Taxus canadensis

Five taxanes with an amino-side chain on C-5 were identified for the first time in the needles of the Canadian yew, Taxus canadensis. Their structures were characterized as 2alpha,7beta,9alpha,10beta,13-pentaacetoxy-11beta-hydroxy-5alpha-(3'-N,N-dimethylamino-3'-phenyl)-propionyloxytaxa-4(20),12-diene (1), 2alpha,9alpha-dihydroxy-10beta,13alpha-diacetoxy-5alpha-(3'-methylamino-3'-phenyl)-propionyloxytaxa-4(20),11-diene (2), 2alpha17-dihydroxy-9alpha,10beta,13alpha-triacetoxy-5alpha-(3'-N,N-dimethylamino-3'-phenyl)-propionyloxytaxa-4(20),11-diene (3), 2alpha-hydroxy-7beta,9alpha,10beta,13alpha-tetraacetoxy-5alpha-(2'-hydroxy-3'-N,N-dimethylamino-3'-phenyl)-propionyloxytaxa-4(20),11-diene (4), and 9alpha-hydroxy-2alpha,10beta,13alpha-triacetoxy-5alpha-(3'-N,N-dimethylamino-3'-phenyl)-propionyloxytaxa-4(20),11-diene (5) on the basis of 1D-, 2D-NMR spectroscopic data and high-resolution fast atom bombardment MS analyses. Metabolite (1) was isolated from the needles of the Canadian yew for the first time but had previously been detected in the stems of the Japanese yew, whereas taxanes (2-5) are only now reported. Metabolite (3) is the first reported nitrogen-containing taxane with a 17-hydroxyl substitution.     

Antifungal highly oxygenated guaianolides and other constituents from Ajania fruticulosa.

Three highly oxygenated guaianolides were isolated from the aerial parts of Ajania fruticulosa along with 17 known phytochemicals including a triterpene (alpha-amyrin), two plant sterols (beta-sitosterol, daucosterol), four flavonoids (axillarin, centaureidin, santin and 5,7,4'-trihydroxy-3,3'-dimethoxyflavone), and ten sesquiterpenes [1alpha-hydroperoxy-4beta,8alpha,10alpha,13-tetrahydroxyguaia-2-en-12,6alpha-olide, 1alpha-hydroperoxy-4alpha,10alpha-dihydroxyguaia-9alpha-angeloyloxyguaia-2,11(13)-dien-12,6alpha-olide, 3beta,4alpha-dihydroxyguaia-11(13),10(14)-dien-12,6alpha-olide, 1alpha,4alpha,10alpha-trihydroxy-9alpha-angeloyloxyguaia-2,11(13)-dien-12,6alpha-olide, 1beta,2beta-epoxy-3beta,4alpha,10alpha-trihydroxy-guaia-11(13)-en-12,6alpha-olide and 2-oxo-8alpha-hydroxyguaia-1(10),3,11(13)-trien-12,6alpha-olide, ketoplenolide B, alantolactone, 9beta-hydroxyeudesma-4,11(13)-dien-12-oic acid and 9beta-acetoxyeudesma-4,11(13)-dien-12-oic acid]. The structures of the three guaianolides were elucidated by a combination of spectroscopic methods (EIMS, HREIMS, COSY, HMQC, HMBC and NOESY) as 1beta,2beta-epoxy-3beta,4alpha,8beta,10alpha-tetrahydroxyguaia-11(13)-en-12,6alpha-olide (1), 1beta,2beta-epoxy-3beta,4alpha,9alpha,10alpha-tetrahydroxyguaia-11(13)-en-12,6alpha-olide (2) and 1beta,2beta-epoxy-10alpha-hydroperoxy-3beta,4alpha,8beta-trihydroxyguaia-11(13)-en-12,6alpha-olide (3), respectively. Antifungal bioassay of all isolates showed that guaianolides 1, 2, 3, and 1beta,2beta-epoxy-3beta,4alpha,10alpha-trihydroxyguaia-11(13)-en-12,6alpha-olide were inhibitory to the growth of Candida albicans with MICs being 20, 20, 20, and 40 microg/ml, respectively.     

Diterpenes and sesquiterpenes from the bark of Taxus yunnanensis

Two taxane-type diterpenes, 10beta-acetoxy-2alpha,5alpha,7beta,9alpha-tetrahydroxytaxa-4(20),11-dien-13-one and 2alpha-acetoxy-9alpha-benzoyloxy-5alpha,7beta,10beta,15-tetrahydroxy-11(15-->1)- abeotaxa-4(20),11-dien-13-one, and two new drimane-type sesquiterpenes, 1beta-acetoxy-7-drimen-11alpha-ol-12,11-lactone and 1beta-acetoxy-11,12-epoxy-6-drimen-8alpha,11alpha-diol, were isolated from the bark of Taxus yunnanensis together with 35 known taxane-type diterpenes, a known drimane-type sesquiterpene and a known flavanone.     

New 2(3-->20)abeotaxane and 3,11-cyclotaxane from needles of Taxus cuspidata

Two new taxoid metabolites, 2alpha,7beta,10beta-triacetoxy-5alpha,13alpha-dihydroxy-2(3-->20)abeotaxa-4(20),11-dien-9-one (1) and 2alpha-acetoxy-5alpha-cinnamoyloxy-9alpha,10beta-dihydroxy-3,11-cyclotax-4(20)-en-13-one (2), were isolated from the methanol extract of needles of the Japanese yew, Taxus cuspidata.     

Synthesis of 4,19-disubstituted derivatives of DOC. Radioreceptor assay of some corticosteroid derivatives in human mononuclear leukocytes

Several new 4,19-substituted steroids and previously synthesized corticosteroids were assayed for affinity to type 1 receptors in human mononuclear leukocytes. 11 beta,19-epoxy-4,21-dihydroxypregn-4-ene-3,20-dione (2) was hydrogenated with Pd-C to yield a mixture of all four dihydro derivatives 5, accompanied by 4,21-diacetoxy-11 beta,19-epoxy-3-hydroxypregnan-20-one (6) and 21-acetoxy-11 beta,19-epoxy-4-hydroxypregnane-3,20-dione (7). With hot acetic + p-toluenesulfonic acid 5 underwent rearrangement to 21-acetoxy-11 beta,19-epoxypregn-5-ene-4,20-dione (8) Pd-C hydrogenation of 3,21-diacetoxy-5 beta,19-cyclopregna-2,9(11)-diene-4,20-dione (10) gave 3,21-diacetoxy-5 beta,19-cyclopregn-5-ene-4,20-dione (11) and the 9,11-dihydro derivative of the latter. Treatment of 10 with warm HCl furnished 19-chloro-4,21-dihydroxypregna-4,9(11)-diene-3,20-dione (13). Pd-C hydrogenation of its diacetate 14 afforded the 4,5-dihydro derivative 18, 19-chloro-21-acetoxypregn-9(11)-en-20-one (15), its 4-acetoxy derivative 16 and the 3,4-diacetoxy derivative 17. When tested in a radioreceptor assay in human mononuclear leukocytes the synthesized compounds showed only low relative binding affinities (RBA) to type 1 receptor, the highest being 0.72% for 13 (aldosterone = 100%). For comparison, other RBA in this system were: 19-noraldosterone, 20%; 18-deoxyaldosterone, 5.8%; 18-deoxy-19-noraldosterone, 4.7%; 18,21-anhydroaldosterone, 0.37%; 17-isoaldosterone, 7.6% and apoaldosterone, 4.3%     

Two new alkaloidal taxoids from the needles of Taxus canadensis

Two new taxanes with a dimethylamino group on the C-5 side chain were identified for the first time in the needles of the Canadian yew, Taxus canadensis. Their structures were characterized as 7beta,10beta,13alpha-triacetoxy-5alpha-(3'-dimethylamino-3'-phenylpropanoyl)oxy-2alpha-hydroxy-2(3-->20)abeotaxa-4(20),11-dien-9-one (1) and 2alpha,10beta-diacetoxy-9alpha-hydroxy-5alpha-(3'-dimethylamino-3'-phenylpropanoyl)oxy-3,11-cyclotax-4(20)-en-13-one (2).     

Novel taxa-4(20),12-diene and 2(3→20)abeotaxane from needles of Taxus canadensis

A novel 6/8/6-membered taxane with a rare C-12(13)-double bond and rare 2(3→20)abeotaxane were isolated from the needles of Taxus canadensis. Their structures were characterized as 7β,9α,10β-triacetoxytaxa-4(20),12-diene-2α,5α,11β-triol (1) and 2α,7β,10β-triacetoxy-5α-hydroxy-2(3→20)abeotaxa-4(20),11-diene-9,13-dione (2) on the basis of 1D and 2D spectroscopic data. 1 is the first example of a natural taxane without substitution at both C-13 and C-14.     

Stemodane and stemarane diterpenoid hydroxylation by Mucor plumbeus and Whetzelinia sclerotiorum

Incubation of stemodin (1) with Mucor plumbeus ATCC 4740 resulted in the formation of 2alpha,6beta,13-trihydroxystemodane (2), 2alpha,3beta,13-trihydroxystemodane (3), 2alpha,11beta,13-trihydroxystemodane (4) and 2alpha,13,14-trihydroxystemodane (5), while stemodinone (7) afforded 6alpha,13-dihydroxystemodan-2-one (8) and 6alpha,12alpha,13-trihydroxystemodan-2-one (9). Metabolites obtained from the bioconversion of stemarin (11) were 8,13,19-trihydroxystemarane (12) and 2alpha,13,19-trihydroxystemarane (13). 19-N,N-Dimethylcarbamoxy-13-hydroxystemarane (14) was not transformed by the fungus. Stemodin (1) was incubated with Whetzelinia sclerotiorum ATCC 18687 to produce 2alpha,7beta,13-trihydroxystemodane (6) and 2alpha,11beta,13-trihydroxystemodane (4). Stemodinone (7) was converted to 7beta,13-dihydroxystemodan-2-one (10). Compounds 2, 4, 9, 10, 12 and 13 have not been previously reported.     

Microbial and reducing agents catalyze the rearrangement of taxanes

5alpha, 7beta, 9alpha, 10beta, 13alpha-Pentahydroxy-4(20),11(12)-taxadiene derivative 1 was converted to two unprecedented 1(15-->11)abeo-taxanes and a taxane derivative with a C10-C11 double bond by Absidia coerula ATCC 10738a. A similar compound was obtained from treatment with zinc of a triacetoxy-4(20),11(12)-taxadiene derivative.     

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

A novel 6/8/6-membered taxane with a rare C-12(13)-double bond and rare 2(3→20)abeotaxane were isolated from the needles of Taxus canadensis. Their structures were characterized as 7β,9α,10β-triacetoxytaxa-4(20),12-diene-2α,5α,11β-triol (1) and 2α,7β,10β-triacetoxy-5α-hydroxy-2(3→20)abeotaxa-4(20),11-diene-9,13-dione (2) on the basis of 1D and 2D spectroscopic data. 1 is the first example of a natural taxane without substitution at both C-13 and C-14.     

Terpenoids from the liverwort Blepharostoma trichophyllum

Blepharostol, a new sesquiterpenoid alcohol with a rearranged drimane skeleton and five new ent-labdane diterpenoids, ent-labda-13(16),14-diene-8alpha-ol, ent-labda-13(16),14-diene-1beta,8alpha-diol, ent-labda-13(16),14-diene-8alpha,9beta-diol, ent-labda-13(16),14-diene-1beta,8alpha,9beta-triol and ent-8alpha,9beta-dihydroxylabda-13(16),14-dien-1-one, have been isolated from the liverwort Blepharostoma trichophyllum. Their structures have been assigned on the basis of their spectroscopic properties.     

Recognition of D-homoannulation by proton and carbon NMR spectra

One-and two dimensional proton and carbon NMR spectra of the D-homoannulated rearrangement product of triamcinolone (9 alpha-fluoro-11 beta,16 alpha,17 alpha, 21-tetrahydroxy-pregna-1,4-diene-3,20-dione) establish its structure as that of 9 alpha-fluoro-11 beta,16 alpha,17 alpha-trihydroxy-17 beta-hydroxy-methyl-D-homoandrosta-1,4-diene-3,17 alpha-dione. These methods accord ready recognition of D-homoannulation of C21-17-hydroxy-20-ketosteroids.     

Two new taxanes from the needles and branches bark of Taxus cuspidata

Two new taxanes were isolated from the MeOH extract of the needles and branches bark of the Japanese yew, Taxus cuspidata. The structures were established as (2alpha,5alpha,7beta,9alpha,10beta,13alpha)-5,10,13,20-tetraacetoxytax-11-ene-2,7,9-triol (1) and (2alpha,5alpha,9alpha,10beta)-2,9,10-triacetoxy-5-[(beta-D-glucopyranosyl)oxy]-3,11-cyclotax-11-en-13-one (2) on the basis of in-depth 1D- and 2D-NMR analyses. Compound 2 is the first example of a transannular taxane glycoside isolated from a natural source.     

The bioactivity-guided isolation and structural identification of toxic cucurbitacin steroidal glucosides from stemodia kingii

A histologically validated murine model for the ovine intoxication by Stemodia kingii was used as a bioassay to guide the isolation of several groups of toxins from Stemodia kingiL Two of the toxins from one group were purified sufficiently to allow structural analysis and a determination of their median lethal doses (LD50) for oral administration to mice. A combination of acid hydrolysis, elemental analysis, HPLC-MS, 1D-NMR (1H, 13C) and 2D-NMR (1H-1H COSY, 13C-1H HSQC and HMBC, and gNOESY) was used to define stemodiosides B3 and B4 as cucurbitacin steroidal glucosides. Thus stemodioside B3 is (24Z)-3 alpha-(beta-glucopyranosyloxy)-2 beta,20,27-trihydroxy- 19-(10 -9 beta)-abeo-10alpha-lanost-5,24-diene- 11-one and stemodioside B4 is (23E)-3 alpha-(beta-glucopyranosyloxy)-20,20,22,27-tetrahydroxy- 19-( 10-9 beta)-abeo- 10 alpha-lanost-5,23-diene- 11-one. The approximate oral LD50s for stemodiosides B3 and B4 in mice were estimated to be 99 and 42 mg/kg body weight, respectively.     

Isolation and structure elucidation of the major photodegradation products of loteprednol etabonate

Photodegradation of loteprednol etabonate (5), a steroid anti-inflammatory drug, in the solid state, in aqueous suspension, and in aqueous acetonitrile solution has been investigated. Analysis by HPLC showed that the profile of photodegradation products in the solid state was qualitatively similar to that in the aqueous suspension, although the profile in the aqueous acetonitrile solution was considerably different. The major photodegradation products were isolated from the aqueous suspension and the aqueous acetonitrile solution by using preparative reversed-phase HPLC and their structures were elucidated on the basis of spectroscopic data. Photolysis in the solid state and in aqueous suspension yielded three rearrangement products, chloromethyl 17alpha-ethoxycarbonyloxy-11beta-hydroxy-5alpha-methyl-2-oxo-19-norandrosta-1(10),3-diene-17beta-carboxylate (8), chloromethyl 17alpha-ethoxycarbonyloxy-11beta-hydroxy-1-methyl-3-oxo-6(5-->10alpha)-abeo-19-norandrosta-1,4-diene-17beta-carboxylate (9), and chloromethyl 1beta,11beta-epoxy-17alpha-ethoxycarbonyloxy-2-oxo-10alpha-androsta-4-ene-17beta-carboxylate (10). In aqueous acetonitrile solution, 10 was the major product, however, 8 and 9 were not obtained. Pathways for the formation of these compounds from loteprednol etabonate (5) are proposed.     

Substrate specificity for the hydroxylation of polyoxygenated 4(20),11-taxadienes by Ginkgo cell suspension cultures

Three C-14 oxygenated taxanes isolated from callus cultures of Taxus spp., 2alpha,5alpha,10beta,14beta-tetra-acetoxy-4(20),11-taxadiene 3, 2alpha,5alpha,10beta-triacetoxy-14beta-propionyloxy-4(20),11-taxadiene 4, 2alpha,5alpha,10beta-triacetoxy-14beta-(2-methylbutyryl)-oxy-4(20),11-taxadiene 5, and three deacetylated derivatives of 3, 10beta-hydroxy-2alpha,5alpha,14beta-triacetoxy-4(20),11-taxadiene 6, 14beta-hydroxy-2alpha,5alpha,10beta-triacetoxy-4(20),11-taxadiene 7, 10beta,14beta-dihydroxy-2alpha,5alpha-diacetoxy-4(20),11-taxadiene 8, could all be regio- and stereo-selectively hydroxylated at the 9alpha-position by Ginkgo cell suspension cultures to yield a series of new 9alpha,14beta-dihydroxylated taxoids. The effects of functional groups, especially at C-14 of the substrates, on the biotransformation were also investigated. The results revealed that substrates with an acetoxyl group at C-14 could be more efficiently 9alpha-hydroxylated than those with a longer ester chain or a hydroxyl group at C-14. An acetoxyl or hydroxyl group at C-10 had no effect on the conversion rates of the substrates, but substrates with the hydroxyl group (compared with the acetoxyl analogues) could be converted into 9alpha-hydroxylated products more easily.     

Synthesis of some epoxy and/or N-oxy 17-picolyl and 17-picolinylidene-androst-5-ene derivatives and evaluation of their biological activity

Steroidal epoxy and/or N-oxy 17-picolyl and 17-picolinylidene-androst-5-ene derivatives have been prepared using 3beta,17beta-dihydroxy-17alpha-picolyl-androst-5-ene (1), 3beta-acetoxy-17-picolinylidene-androst-5-ene (2), and 3beta-hydroxy-17-picolinylidene-androst-5-ene (3) as synthetic precursors. The compounds 2 and/or 3 were reacted with m-chloroperoxybenzoic acid (MCPBA). The compounds synthesized from 2 were 17-picolinylidene-N-oxide 4, 5alpha,6alpha-epoxy and 5beta,6beta-epoxy-17-picolinylidene-N-oxide 5 and 6, and 5alpha,6alpha:17alpha,20alpha- and 5beta,6beta:17alpha,20alpha-diepoxy-N-oxide 7 and 8. Starting from compound 3, a mixture of 5alpha,6alpha-epoxy and 5beta,6beta-epoxy-17-picolinylidene 9 and 10, 5alpha,6alpha-epoxy and 5beta,6beta-epoxy-17-picolinylidene-N-oxide 11 and 12, and 5alpha,6alpha:17alpha,20alpha- and 5beta,6beta:17alpha,20alpha-diepoxy-N-oxide 13 and 14 were obtained. From compounds 15 and 18, obtained from 1 and 3 by the Oppenauer oxidation, the 4alpha,5alpha-epoxy and 4beta,5beta-epoxy derivatives 16, 17 and 20, 21 were prepared by oxidation with 30% H(2)O(2). Oxidation of 18 with MCPBA yielded only the N-oxide 19. The structures of compounds 15 and 18 were proved by the X-ray analysis. Compounds 1-6, 9, 15, 17, 18, and 21 were tested on activity against the enzyme aromatase. Antitumor activity against three tumor cell lines (human breast adenocarcinoma ER+, MCF-7, human breast adenocarcinoma ER-, MDA-MB-231, and prostate cancer PC3) was evaluated. Three tested compounds (1, 4, and 19) showed strong activity against PC3, the IC(50) values being in the range 0.55-10microM, whereas compound 17 showed strong activity against MDA-MB-231 (IC(50) 10.4microM).     

The chemistry of 9 alpha-hydroxysteroids. 1. Preparation of 9 alpha,17 beta-dihydroxy-17 alpha-ethynylandrost-4-en-3-one

9 alpha-Hydroxyandrost-4-ene-3,17-dione 1, when allowed to react with dipotassium acetylide in tetrahydrofuran, resulted, after chromatographic separation, in 4-methyl-19-norandrosta-4,9-diene-1,17-dione 2, 4 xi-methyl-19-norandrosta-5(10),9(11)-diene-1,17-dione 3, 4-methyl-17 alpha-ethynyl-17 beta-hydroxy-19-norandrosta-4,9-dien-1-one 4, 4 xi-methyl-17 alpha-ethynyl-17 beta-hydroxy-19-norandrosta-5(10),9(11)-dien- 1-one 5, and 17 alpha-ethynyl-17 beta-hydroxy-9,10-secoandrost-4-ene-3,9-dione 6. Selective protection of delta 4-3-ketone of 9 alpha-hydroxyandrost-4-ene-3,17-dione 1 as its dienol methyl ether 7, and subsequent reaction with lithium acetylide-ethylenediamine followed by acidic hydrolysis, afforded 9 alpha,17 beta-dihydroxy-17 alpha- ethynylandrost-4-en-3-one 8.