Microbiological transformation of an ent-pimaradiene hydrocarbon by Gibberella fujikuroi

The hydrocarbon 9,13-epi-ent-pimara-7,15-diene has been obtained from its 18-hydroxy derivative by treatment with Ph₃/CCl₄ and subsequent reduction with tri-n-butyltin hydride. The incubation of this diterpene with the fungus Gibberella fujikuroi afforded 1α,9α-dihydroxy-7α,8α-epoxy-13-epi-ent-pimara-15-ene. The main difference between the biotransformation of the hydrocarbon and that of the corresponding 18-alcohol is that in the former, the rearrangement of the epoxy group to give 7-oxo-derivatives was not observed. However, the sequence of reactions 7α,8α-epoxidation, hydroxylation at C-9α and subsequent C-1α hydroxylation occurred in both biotransformations.     

Extractive compounds of betulaceae family birch buds (Betula pendula Roth.): IV. Composition of sesquiterpene diols, triols, and flavonoids

This report is devoted to study of the hydrocarbon composition of the extract of buds of birch (family Betulaceae). We identified 3,5-dihydroxy-7,4??-dimethoxyflavone, 5,7-dihydroxy-3,4??-dimethoxyflavone, 7-methoxy-4??,5-dihydroxyflavanone, 4??-methoxy-5,7-hydroxyflavanone, 5??,6??-dihydroxycaryophyllen-4(14),8(15)-diene ((1R,5R,6R,9S)-5,6-dihydroxy-11,11-dimethyl-4,8-methylenebicyclo[7.2.0]-undecane), 5??,6??-dihydroxycaryophyllen-3,8(15)-diene ((1R,5R,6R,9S)-5,6-dihydroxy-11,11-dimethyl-8-methylenebicyclo[7.2.0]undec-3-ene), 6??,9??-dihydroxy-??-humulene((1E,4E,6R,9S)-6,9-dihydroxy-4,11,11-trimethyl-8-methylene-1,4-cycloundecanediene), 5??,6??,8??-trihydroxycariolan, and (1R,5R,6R,8R,9S)-trihydroxycariolan. The gas chromatographic retention indices of all identified compounds were determined.     

Sesqui- and diterpenes from the liverwort Gackstroemia decipiens

Six rosanes, 5 beta,11 beta-dihydroxy-ros-15-ene, 5 beta,12 beta-dihydroxy-ros-15-ene, 11 beta-hydroxy-7-oxo-rosa-5,15-diene, 1 alpha,5 beta,11 beta-trihydroxy-7-oxo-ros-15-ene, 5 beta,20-epoxy-20-hydroxy-ros-15-ene and 5 beta,20-epoxy-20-methoxy-ros-15-ene along with the enantiomer of the already reported 11 beta-hydroxy-rosa-5,15-diene and the known 5 beta-hydroxy-ros-15-ene have been isolated from the liverwort Gackstroemia decipiens. Furthermore, the sesquiterpenes 3-acetoxy-7,11-dihydroxy-farnesa-1,5,9-triene and 1 beta,10 beta-epoxy-nardosin-7,11-diene were identified. Their structures were elucidated by NMR spectroscopy.     

Synthesis of the marine epoxy sterol 9 alpha,11 alpha-epoxy-5 alpha-cholest-7-ene-3 beta,5,6 beta-triol

The synthesis of 9 alpha,11 alpha-epoxy-5 alpha-cholest-7-ene-3 beta,5,6 beta-triol (1), a highly oxygenated marine sterol containing a 9,11-epoxide moiety in the nucleus, is described. Epoxy sterol 1 was synthesized from cholesta-5,7-dien-3 beta-ol. Oxidation of this sterol with m-chloroperbenzoic acid followed by hydrolysis and acetylation furnished 5 alpha-cholest-7-ene-3 beta,5,6 alpha-triol 3,6-diacetate (2). Mercuric acetate dehydrogenation of diacetate 2, followed by oxidation with manganese dioxide and epoxidation with m-chloroper-benzoic acid, afforded 9 alpha,11 alpha-epoxy-3 beta,5-dihydroxy-5 alpha-cholest-7-en-6-one (5). Reduction of 5 with lithium aluminum hydride gave the desired compound 1. The structures of all synthetic intermediates were confirmed by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. A reassignment of resonances for carbons 1, 8, and 15 in the 13C NMR spectrum of 1, based on 2D-NMR correlation spectroscopy, has been accomplished.     

Microbial transformation of mesterolone

The microbial transformation of mesterolone (= (1alpha,5alpha,17beta)-17-hydroxy-1-methylandrostan-3-one; 1), by a number of fungi yielded (1alpha,5alpha)-1-methylandrostane-3,17-dione (2), (1alpha,3beta,5alpha,17beta)-1-methylandrostane-3,17-diol (3), (5alpha)-1-methylandrost-1-ene-3,17-dione (4), (1alpha,5alpha,15alpha)-15-hydroxy-1-methylandrostane-3,17-dione (5), (1alpha,5alpha,6alpha,17beta)-6,17-dihydroxy-1-methylandrostan-3-one (6), (1alpha,5alpha,7alpha,17beta)-7,17-dihydroxy-1-methylandrostan-3-one (7), (1alpha,5alpha,11alpha,17beta)-11,17-dihydroxy-1-methylandrostan-3-one (8), (1alpha,5alpha,15alpha, 17beta)15,17-dihydroxy-1-methylandrostan-3-one (9), and (5alpha,15alpha,17beta)-15,17-dihydroxy-1-methylandrost-1-en-3-one (10). Metabolites 5-10 were found to be new compounds. All metabolites, except 2, 3, 6, and 7, exhibited potent anti-inflammatory activity. The structures of these metabolites were characterized on the basis of spectroscopic studies, and the structure of 5 was also determined by single-crystal X-ray-diffraction analysis.     

Stereospecific 1,4-addition to an alpha,beta-unsaturated steroidal epoxide: syntheses of new 15-oxygenated sterols

3 beta-Benzoyloxy-14 alpha,15 alpha-epoxy-5 alpha-cholest-7-ene (1) is a key intermediate in the synthesis of C-7 and C-15 oxygenated sterols. Treatment of 1 with benzoyl chloride resulted in the formation of 3 beta,15 alpha-bis-benzoyloxy-7 alpha-chloro-5 alpha-cholest-8(14)-ene (2). Reaction of 2 with LiAlH4 or LiAlD4 resulted in the formation of 5 alpha-cholest-7-ene-3 beta,15 alpha-diol (3a) or [14 alpha-2H]5 alpha-cholest-7-ene-3 beta,15 alpha-diol (3b). Diol 3b was selectively oxidized by Ag2CO3/celite to [14 alpha-2H]5 alpha-cholest-7-en-15 alpha-ol-3-one (4). Treatment of 1 with MeMgI/CuI gave 7 alpha-methyl-5 alpha-cholest-8(14)-ene-3 beta,15 alpha-diol (5). Selective oxidation of 5 with pyridinium chlorochromate (PCC)/pyridine or oxidation with PCC resulted in the formation of 7 alpha-methyl-5 alpha-cholest-8(14)-en-3 beta-ol-15-one (6) and 7 alpha-methyl-5 alpha-cholest-8(14)-ene-3,15-dione, respectively. Reduction of 6 with LiAlH4 yielded 5 and 7 alpha-methyl-5 alpha-cholest-8(14)-ene-3 beta,15 beta-diol (6). Reaction of 1 with benzoic acid/pyridine gave 3 beta,7 alpha-bis-benzoyloxy-5 alpha-cholest-8(14)-en-15 alpha-ol (9). Treatment of 9 with LiAlH4 or ethanolic KOH resulted in the formation of 5 alpha-cholest-8(14)-ene-3 beta,7 alpha,15 alpha-triol (10). Dibenzoate 9, upon brief treatment with mineral acid, gave 3 beta-benzoyloxy-5 alpha-cholest-8(14)-ene-15-one (11). Oxidation of 9 with PCC yielded 3 beta,7 alpha-bis-benzoyloxy-5 alpha-cholest-8(14)-ene-15-one (12). Ketone 12 was also prepared by the selective hydride reduction of 5 alpha-cholest-8(14)-en-7 alpha-ol-3,15-dione (13) to give 5 alpha-cholest-8(14)-ene-3 beta,7 alpha-diol-15-one (14), which was then treated with benzoyl chloride to produce 12.     

A new chemical synthesis of 5alpha-cholest-8(14)-en-3beta,5alpha-diol

Reduction of 3beta-benzoyloxy-14alpha,15alpha-epoxy-5alpha-cholest-7-ene with lithium in ethylenediamine gave 5alpha-cholest-8(14)-en-3beta, 5alpha-diol in high yield. This procedure offers an alternate synthesis through the reductive rearrangement of an alpha,beta-unsaturated steroidal epoxide.     

Biosynthesis of rice phytoalexins: identification of putative diterpene hydrocarbon precursors.

A procedure for the preparation of a cell-free enzyme solution from rice leaves capable of catalyzing the biosynthesis of diterpene hydrocarbons from geranylgeranyl pyrophosphate or copalyl pyrophosphate as added substrates has been developed. The rates of synthesis of a group of "pimaradiene-like" diterpene hydrocarbons are about 75-fold higher with geranylgeranyl pyrophosphate as substrate and about 8-fold higher with copalyl pyrophosphate as substrate in comparison with extracts from untreated control leaves. The maximum rate of diterpene hydrocarbon biosynthesis is seen in extracts prepared at 40 h after uv irradiation. Five diterpene hydrocarbons (compounds A-E) were present in the hydrocarbon fraction biosynthesized from [3H]geranylgeranyl pyrophosphate in large-scale incubation mixtures prepared from uv-treated rice leaves. Three of these diterpenes were identified as ent-kaur-16-ene (B), ent-sandaracopimara-8(14), 15-diene (D), and 9 beta H-pimara-7,15-diene (E) from GC retention times and GC-MS spectral characteristics in comparison with those of authentic reference compounds. Compound C has spectral characteristics analogous to those of a pimaradiene, but a specific structural assignment from the data available was not possible. Similar incubations with [3H]copalyl pyrophosphate as the substrate and enzyme prepared from uv-treated rice leaves produced ent-kaurene (B), ent-sandaracopimara-8(14),15-diene (D), and compound C, but not 9 beta H-pimara-7,15-diene (E). These results are consistent with a proposed biosynthetic scheme in which 9 beta H-pimara-7,15-diene serves as a precursor of the momilactone family, and ent-sandaracopimara-8(14),15-diene serves as a precursor of the oryzalexin family of rice phytoalexins. ent-Kaurene was the only diterpene detected in incubation mixtures containing enzyme extract from untreated rice leaves and [3H]copalyl pyrophosphate as the substrate. It is suggested that kaurene biosynthesis in rice leaves is probably associated with gibberellin biosynthesis and the regulation of vegetative growth rather than stress metabolism. The diterpene cyclization enzymes in extracts of uv-treated rice leaves show only a relatively modest inhibition by the plant growth retardants AMO-1618 and Phosfon D. No evidence was obtained for the subcellular localization of these cyclization enzymes in organellar preparations; it is tentatively concluded that the enzymes are present predominantly in the extraorganellar cytoplasm of rice leaves.     

Cytotoxic triterpenes from the aerial roots of Ficus microcarpa

Six triterpenes, 3beta-acetoxy-12,19-dioxo-13(18)-oleanene (1), 3beta-acetoxy-19(29)-taraxasten-20alpha-ol (2), 3beta-acetoxy-21alpha,22alpha-epoxytaraxastan-20alpha-ol (3), 3,22-dioxo-20-taraxastene (4), 3beta-acetoxy-11alpha,12alpha-epoxy-16-oxo-14-taraxerene (5), 3beta-acetoxy-25-methoxylanosta-8,23-diene (6) along with nine known triterpenes, 3beta-acetoxy-11alpha,12alpha-epoxy-14-taraxerene (7), 3beta-acetoxy-25-hydroxylanosta-8,23-diene (8), oleanonic acid (9), acetylbetulinic acid (10), betulonic acid (11), acetylursolic acid (12), ursonic acid (13), ursolic acid (14), and 3-oxofriedelan-28-oic acid (15) were isolated from the aerial roots of Ficus microcarpa, and their structures elucidated by spectroscopic methods. The in vitro cytotoxic efficacy of these triterpenes was investigated using three human cancer cell lines, namely, HONE-1 nasopharyngeal carcinoma, KB oral epidermoid carcinoma, and HT29 colorectal carcinoma cells. Compound 8 and pentacyclic triterpenes 9-15 possessing a carboxylic acid functionality at C-28 showed significant cytotoxic activities against the aforementioned cell lines and gave IC50 values in the range 4.0-9.4 microM.     

ent-Clerodane diterpenes and other constituents from the liverwort Adelanthus lindenbergianus (Lehm.) Mitt

Eleven ent-clerodanes, 13-hydroxy-cis-ent-cleroda-3,14-diene, 15-hydroxy-cis-ent-cleroda-3,13(E)-diene, 1beta,12:15,16-diepoxy-cis-ent-cleroda-13(16),14-dien-18alpha,6alpha-olide, 8beta,12:15, 16-diepoxy-cis-ent-cleroda-13(16),14-dien-18alpha,6alpha-olide, 1beta,16:15,16-diepoxy-cis-ent-cleroda-12,14-dien-18alpha,6alpha-olide, 7beta,12:8beta,12-diepoxy-15-hydroxy-cis-ent-cleroda-13-en-16,15:18alpha,6alpha-diolide, 7beta,12:8beta,12-diepoxy-16-hydroxy-cis-ent-cleroda-13-en-15,16:18alpha,6alpha-diolide, 1alpha-acetoxy-8beta,12-epoxy-15-hydroxy-cis-ent-cleroda-13-en-16,15:18alpha,6alpha-diolide, 1beta,12-epoxy-16-hydroxy-cis-ent-cleroda-13-en-15,16:18alpha,6alpha-diolide, 8beta,12-epoxy-15-hydroxy-trans-cleroda-13-en-16,15:18alpha,6alpha-diolide, 8beta,12-epoxy-16-hydroxy-trans-cleroda-13-en-15,16:18alpha,6alpha-diolide along with the known clerodane diterpenes anastreptin and orcadensin have been isolated from the liverwort Adelanthus lindenbergianus (Lehm.) Mitt. Furthermore, three eudesmane sesquiterpenes together with the known (-)-1beta,10-epoxyaristolan, 3,4-seco-4(23),20(29)-lupadien-3,28-dicarboxylic acid dimethyl ester and two acetophenone derivatives were identified by spectroscopic methods, essentially MS and NMR experiments.     

Synthesis of (25R)-26-hydroxy-15-ketosterols

(25R)-3beta,26-Dihydroxy-5alpha-cholest-8(14)-en-15-one (1) and (25R)-3beta,26-dihydroxy-5alpha,14beta-cholest-16-en-1 5-one (2) were synthesized from (25R)-3beta,26-dibenzoyloxy-5alpha,14alpha-chole st-16-ene (4). Oxidation of 4 with CrO3-3,5-dimethylpyrazole at -20 degrees C gave (25R)-3beta,26-dibenzoyloxy-5alpha,14alpha-chole st-16-en-15-one (5) along with (25R)-3beta,26-dibenzoyloxy-5alpha-cholest-16alpha+ ++,17alpha-epoxide (6). Oxidation of 5 with selenium dioxide afforded (25R)-3beta,26-dibenzoyloxy-5alpha-cholest-8(14),16-++ +dien-15-one (7) and (25R)-3beta,26-dibenzoyloxy-5alpha,14beta-choles t-16-en-15-one (8). Selective hydrogenation of 7 followed by hydrolysis in alcoholic potassium hydroxide yielded (25R)-3beta,26-dihydroxy-5alpha-cholest-8(14)-en-15-one (1). Hydrolysis of 5 and 8 in alcoholic potassium hydroxide provided (25R)-3beta,26-dihydroxy-5alpha,14beta-cholest-16-en-1 5-one (2).     

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 microbiological transformation of 7alpha-hydroxy-ent-kaur-16-ene derivatives by Gibberella fujikuroi

The biotransformation of 7alpha-hydroxy-ent-kaur-16-ene (epi-candol A) by the fungus Gibberella fujikuroi gave 7alpha,16alpha,17-trihydroxy-ent-kaur-16-ene and a seco-ring B derivative, fujenoic acid, whilst the incubation of candicandiol (7alpha,18-dihydroxy-ent-kaur-16-ene) and canditriol (7alpha,15alpha,18-trihydroxy-ent-kaur-16-ene) afforded 7alpha,18,19-trihydroxy-ent-kaur-16-ene and 7alpha,11beta,15alpha,18-tetrahydroxy-ent-kaur-16-ene, respectively. The presence of a 7alpha-hydroxyl group in epi-candol A avoids its biotransformation along the biosynthetic pathway of gibberellins, and directs it to the seco-ring B acids route. The 15alpha-hydroxyl group in canditriol inhibits oxidation at C-19 and direct hydroxylation at C-11(beta). The formation of fujenoic acid, from 7alpha-hydroxy-ent-kaur-16-ene, probably occurs via 7alpha-hydroxykaurenoic acid and 7-oxokaurenoic acid, with subsequent hydroxylation at the C-6(beta) position.     

Inhibitors of sterol synthesis. Chemical syntheses, properties and effects of 4,4-dimethyl-15-oxygenated sterols on sterol synthesis and on 3-hydroxy-3-methylglutaryl coenzyme A reductase activity in cultured mammalian cells

The chemical syntheses of a number of 4,4-dimethyl substituted 15-oxygenated sterols have been pursued to permit evaluation of their activity in the inhibition of the biosynthesis of cholesterol and other biological effects. Described herein are the first chemical syntheses of 4,4-dimethyl-14 alpha-ethyl-5 alpha-cholest-7-en-3 beta-ol-15-one, 3 beta,15 alpha-diacetoxy-4,4-dimethyl-14 alpha-ethyl-5 alpha-cholest-7-ene, 3 beta-acetoxy-4,4-dimethyl-14 alpha-ethyl-5 alpha-cholest-7-en-15 beta-ol, 4,4-dimethyl-14 alpha-ethyl-5 alpha-cholest-7-ene-3 beta,15 alpha-diol, 4,4-dimethyl-14 alpha-ethyl-5 alpha-cholest-7-ene-3 beta,15 beta-diol, 4,4-dimethyl-14 alpha-ethyl-5 alpha-cholest-7-en-15 alpha-ol-3-one, 3 beta-benzoyloxy-4,4-dimethyl-5 alpha-cholest-8(14)-ene-7 alpha,15 alpha-diol, 7 alpha,15 alpha-diacetoxy-3 beta-benzoyloxy-4,4-dimethyl-5 alpha-cholest-8(14)-ene, 4,4-dimethyl-5 alpha-cholest-8(14)-en-3 beta-ol-15-one and 3 beta,7 alpha,15 alpha-tri-o-bromobenzoyloxy-5 alpha-cholest-8(14)-ene. Also prepared for use in the biological experiments were 4,4-dimethyl-5 alpha-cholest-7-ene-3 beta,15 alpha-diol, 4,4-dimethyl-5 alpha-cholest-8-ene-3 beta,15 alpha-diol and 4,4-dimethyl-5 alpha-cholest-8(14)-ene-3 beta,7 alpha,15 alpha-triol. The effects of twelve 4,4-dimethyl substituted 15-oxygenated sterols and of four 4,4-dimethyl substituted 32-oxygenated sterols on sterol synthesis and on the level of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity were evaluated in mouse L cells. With the exception of 4,4-dimethyl-5 alpha-cholest-8(14)-ene-3 beta,7 alpha,15 alpha-triol, all of the 4,4-dimethyl substituted 15-oxygenated sterols caused a 50% inhibition of sterol synthesis at less than 10(-6) M and six of the 4,4-dimethyl substituted 15-oxygenated sterols caused a 50% inhibition of sterol synthesis at less than 10(-7) M. 4,4-Dimethyl-14 alpha-ethyl-5 alpha-cholest-7-ene-3 beta,15 alpha-diol caused a 50% decrease in sterol synthesis at 10(-8) M. The potencies of the 4,4-dimethyl substituted 15-oxygenated and C-32-oxygenated sterols with respect to inhibition of sterol synthesis and suppression of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity have been compared with those of the corresponding sterols lacking the 4,4-dimethyl substitution.     

15 beta-Methyl-5 alpha,14 beta-cholest-7-ene-3 beta,15 alpha-diol. Synthesis, structure, and inhibition of sterol synthesis in animal cells

Treatment of 3 beta-benzoyloxy-14 alpha,15 alpha-epoxy-5 alpha-cholest-7-ene with methyl magnesium iodide gave, as the major product, 15 beta-methyl-5 alpha,14 beta-cholest-7-ene-3 beta,15 alpha-diol. The product was characterized as the free sterol and in the form of its 3 beta-acetoxy and 3 beta-p-bromobenzoate derivatives. Unambiguous assignment of structure was based upon X-ray analysis of the latter derivative. 15 beta-Methyl-5 alpha,14 beta-cholest-7-ene-3 beta,15 alpha-diol was found to be a potent inhibitor of sterol synthesis in cultured mammalian cells. The 15 beta-methyl-3 beta,15 alpha-dihydroxysterol caused a 50% reduction of the level of HMG-CoA reductase activity and a 50% reduction in the incorporation of labeled acetate into digitonin-precipitable sterols in L cells at a concentration of 3.0 x 10(-6) M.     

Two cyathane-type diterpenoids from the liquid culture of Strobilurus tenacellus

The structures of two new cyathane-type diterpenoids isolated from a liquid culture of Strobilurus tenacellus have been elucidated. The chemical structures of the new compounds 1 and 2 were identified as (12S)-11alpha,14alpha-epoxy-13alpha,14beta,15-trihydroxycyath-3-ene and (12R)-11alpha,14alpha-epoxy-13alpha,14beta,15-trihydroxycyath-3-ene, respectively, by spectral methods, including HR-EI-MS, and 1D- and 2D-NMR techniques. Compounds 1 and 2 show antimicrobial activity against Pseudomonas aeruginosa. In addition, both compounds were also tested for activity against human cancer cells, and 2 showed growth inhibitory activity against YMB and COLO 201 cells.     

Trichothecene mycotoxins from Fusarium sulphureum

Four mycotoxins isolated from moulded maize cultures of Fusarium sulphureum have been characterized as 3α,4β,15-triacetoxy-12,13-epoxytrichothec-9-ene, 4β,15-diacetoxy-3α-hydroxy-12,13-epoxytrichothec-9-ene, 15-acetoxy-3α,4β-dihydroxy-12,13-epoxytrichothec-9-ene and 4β-acetoxy-3α,15-dihydroxy-12,13-epoxytrichothec-9-ene.     

ent-Kauranoid derivatives from Sideritis moorei

Seven new ent-kauranoid derivatives ent-7alpha,18-dihydroxykaur-16-en-3-one, ent-18-acetoxy-3beta,7alpha-dihydroxykaur-15-en-17-al, ent-3beta-acetoxy-7alpha,18-dihydroxykaur-15-en-17-al, ent-18-acetoxy-3beta,7alpha,17-trihydroxykaur-15-ene, ent-3beta-acetoxy-7alpha,17,18-trihydroxykaur-15-ene, ent-18-acetoxy-3beta,7alpha,17-trihydroxy-15beta,16beta-epoxykaurane and ent-3beta-acetoxy-7alpha,17,18-trihydroxy-15beta,16beta-epoxykaurane have been isolated from Sideritis moorei. The structures of these compounds have been established by spectroscopic means and chemical correlations.     

Biotransformation of 7α-hydroxy- and 7-oxo-ent-atis-16-ene derivatives by the fungus Gibberella fujikuroi

The microbiological transformation of 7α,19-dihydroxy-ent-atis-16-ene by the fungus Gibberella fujikuroi gave 19-hydroxy-7-oxo-ent-atis-16-ene, 13(R),19-dihydroxy-7-oxo-ent-atis-16-ene, 7α,11β,19-trihydroxy-ent-atis-16-ene and 7α,16β,19-trihydroxy-ent-atis-16-ene, while the incubation of 19-hydroxy-7-oxo-ent-atis-16-ene afforded 13(R),19-dihydroxy-7-oxo-ent-atis-16-ene and 16β,17-dihydroxy-7-oxo-ent-atisan-19-al. The biotransformation of 7-oxo-ent-atis-16-en-19-oic acid gave 6β-hydroxy-7-oxo-ent-atis-16-en-19-oic acid, 6β,16β,17-trihydroxy-7-oxo-19-nor-ent-atis-4(18)-ene and 3β,7α-dihydroxy-6-oxo-ent-atis-16-en-19-oic acid.