Synthesis of new 10 beta-propargylic and 11 beta-allenic steroidal spirolactones.

As part of continuing studies on the synthesis of new, biologically interesting 11 beta-substituted steroidal spirolactones, we describe here the competition between 10 beta-propargylation and 11 beta-allenylation. Grignard addition of allenyl magnesium bromide to an appropriate 5,10-epoxy-9(11)-olefin provides 10 beta-propargylation or 11 beta-allenylation. The role of the catalytic effect of copper chloride and of the solvent is evaluated. Confirmation of the structural assignments of these new 3,3-ethylenethioxy-10 beta-propargyl (or 11 beta-allenyl)-19-nor-17 alpha-pregna-4,9-diene-21,17-carbolactones is reported.     

2β-hydroxyteucvidin from teucrium webbianum

A new 19-nor-neo-clerodane diterpenoid, 2β-hydroxyteucvidin, has been isolated from the aerial parts of Teucrium webbianum, besides the previously known diterpenoids teuflidin and teucrin A. The structure of 2β- hydroxyteucvidin, (12S)-15,16-epoxy-2β-hydroxy-19-nor-10α-neo-clerodane-4,13(16),14-triene-18,6β;20,12-diolide, was established mainly by spectroscopic means.     

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.     

Metabolism of bile alcohols in the perfused rabbit liver - C26 bile alcohols

The metabolism of a C26 bile alcohol (I, 24-nor-5beta-cho-lestane-3alpha, 7alpha,25-triol) was studied in the isolated perfused rabbit liver. The new bile alcohol and bile acid metabolites secreted into the bile were isolated and identified by a combination of TLC, GLC and GLC-MS. The following bile alcohols were found: II, 24-nor-5beta-cholestane-3alpha,7alpha,12alpha,25-tetrol, III, 24-nor-5beta-cholestane-3alpha,7alpha,12alpha,25,26-pentol; IV, 24-nor-5beta-cholest-23-ene-3alpha,7alpha,12alpha-triol; and V, 24-nor-5beta-cholest-23-ene-3alpha,7alpha-diol. In the bile acid fraction, 24-nor-cholic acid and 3alpha,7alpha,12alpha-trihydroxy-24-nor-5beta-cholest-23-en-26-oic acid were present. The perfused nor-triol was not resistant to 12alpha-hydroxylation.     

neo-Clerodane diterpenoids from Baccharis flabellata

Three diterpenoid derivatives were isolated from the acetone extract of Baccharis flabellata. Their structures were elucidated as 2,19;15,16-diepoxy-neo-clerodan-3,13(16),14-trien-18-oic acid, 15,16-epoxy-5,10-seco-clerodan-1(10),2,4,13(16),14-pentaen-18,19-olide and 15,16-epoxy-neo-clerodan-1,3,13(16),14-tetraen-18,19-olide through spectroscopic analyses.     

Sacculatane diterpenoids from axenic cultures of the liverwort Fossombronia wondraczekii

Five new sacculatane diterpenoids, 17,18-epoxy-7-sacculaten-12,11-olide, 7,17-sacculatadien-11,12-olide, 11beta,12-epoxy-7,17-sacculatadien-11alpha-ol, 1beta-acetoxy-11beta,12-epoxy-7,17-sacculatadien-11alpha-ol and 1beta,15xi-diacetoxy-11,12-epoxy-8(12),9(11),17-sacculatatriene along with sacculatal and sacculatanolide have been isolated from axenic cultures of the liverwort Fossombronia wondraczekii and their structures assigned on the basis of their spectroscopical properties.     

Humirianthenolides,new degraded diterpenoids from Humirianthera rupestris

The tuber of Humirianthera rupestris (Icacinaceae) contains the degraded diterpenoids 3β,20-epoxy-30α- hydroxy- 14-oxo-9β-podocarpan-19,6β-olide (humirianthenolide A), 3β,20-epoxy-3α,14α-dihydroxy-9β-podocarpan-19,6β- olide (humirianthenolide B), 3β,20; 16,14-diepoxy-3α-hydroxy-17-nor-15-oxo-9β-abiet-13-en-19,6β-olide (humirianthenolide C), 3β,20-epoxy-3α,14-dihydroxy-13-oxo-9β-podocarp-8(14)-en-19,6β-olide (humirianthenolide D), 3β,20-epoxy-3α-hidroxy-14-oxo-8α,9β-podocarpan-19,6β-olide (humirianthenolide E) and 3β,20-epoxy-3α,14β- dihydroxy-8α,9β-podocarpan-19,6β-olide (humirianthenolide F). ¹H NMR and ¹³C NMR spectroscopy were efrective for the determination of the humirianthenolide structures.     

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.     

Ecdysteroids and bufadienolides from Helleborus torquatus (Ranunculaceae)

Three bufadienolides, hellebortin A (5-[beta-D-glucopyranosyloxy]-10,14,16-trihydroxy-19-nor-[5beta,10beta,14beta,16beta]-bufa-3,20,22-trienolide [1]), hellebortin B (5-[beta-D-glucopyranosyloxy]-3,4-epoxy-14-hydroxy-19-oxo-bufa-20,22-dienolide [2]) and hellebortin C (5-[beta-D-glucopyranosyloxy]-3,4-epoxy-10,14-dihydroxy-19-nor-bufa-20,22-dienolide [3]), together with 20-hydroxyecdysone 3-O-beta-D-glucoside (4) and 20-hydroxyecdysone (5) have been isolated by bioassay- and RIA-directed HPLC analyses of a methanol extract of the seeds of Helleborus torquatus. The structure and relative stereochemistry of the novel bufadienolide hellebortin A (1) and the structures of hellebortin B (2) and hellebortin C (3) were determined unambiguously by comprehensive analyses of their 1D and 2D NMR data. These five compounds are isolated from Hellborus torquatus for the first time. The biological activities of compound 1, 4 and 5 as ecdysteroid agonists and antagonists have been assessed.     

ent-Beyerane diterpenoids from the heartwood of Excoecaria parvifolia

Chromatographic fractionations of the toluene extract of the heartwood of Excoecaria parvifolia collected in Australia resulted in the isolation of 12 beyerane diterpenes (1-12), and the triterpene, lupeol. Four of the isolated diterpenoids (5-7 and 12) have unusual structures: ent-3-oxa-beyer-15-en-2-one, (5); ent-15,16-epoxy-2-hydroxy-19-norbeyer-1,4-dien-3-one (6); methyl ent-2,4-seco-15,16-epoxy-4-oxo-3,19-dinorbeyer-15-en-2-oate (7); and ent-2,17-dihydroxy-19-norbeyer-1,4,15-trien-3-one (12). The structures were established by spectroscopic analyses, NMR data comparisons with similar diterpenes, and chemical correlations. All the diterpenes are assumed to have the same absolute configuration as the co-occurring (+)-stachenol (4). Diosphenol 2 and nor-lactone 5 exhibited significant potency in bioassays for cytotoxic activity against leukemia cells (L1210). Plausible biosynthetic pathways are proposed to explain the origin of the diterpene metabolites.     

Antibacterial diterpenes and their fatty acid conjugates from rice leaves

Six structurally oryzalide-related compounds, oryzadione (1), 2, 3, 4, 5 and 6, were isolated from a neutral fraction of the extract of healthy leaves using a bacterial leaf blight-resistant cultivar of a rice plant, "Norin-27", as a group of antimicrobial substances. Their structures were determined by spectroscopic studies to be kaurane analogues and kaurane analogues conjugated with fatty acids, i.e., 1: ent-15,16-epoxy-kauran-2,3-dione (enol form: ent-15,16-epoxy-2-hydroxy-kauran-1-en-3-one), 2: ent-15,16-epoxy-3beta-hydroxy-kauran-2-one, 3: ent-15,16-epoxy-3-oxa-kauran-2-one, 4: ent-15,16-epoxy-3beta-myristoyloxy-kauran-2-one, 5: ent-15,16-epoxy-3alpha-palmitoyloxy-kauran-2-one, and 6: ent-15,16-epoxy-2beta-palmitoyloxy-kauran-2-one.     

Three labdane diterpenoids from Aframomum sceptrum (Zingiberaceae)

Three labdane diterpenoids, 8beta,17-epoxy-3beta,7beta-dihydroxy-12(E)-labden-16,15-olide (1), methyl 8beta,17-epoxy-3beta,7beta,15-trihydroxy-12(E)-labden-16-oate (2) and 3beta,7beta,8beta,12zeta,17-pentahydroxylabdan-16,15-olide (3) have been isolated from the seeds of Afromomum sceptrum K. Schum (Zingiberaceae) and their structures assigned on the basis of their spectroscopic properties. Nerolidol, and the known flavonoids 3-acetoxy-4',5,7-trihydroxyflavanone, and 3,4',5,7-tetrahydroxyflavanone were also obtained.     

C(15) Acetogenins from the red alga Laurencia obtusa.

Four C(15) acetogenins, 13-epilaurencienyne (3Z) (1), 13-epipinnatifidenyne (3E) (2), (3E, 6S(*), 7R(*), 9S(*), 10S(*), 12R(*))-9-chloro-13-bromo-6:12-epoxy-7, 10-diacetoxypentadec-3-en-1-yne (3), (3Z, 6S(*), 7R(*), 9S(*), 10S(*), 12R(*))-9-chloro-13-bromo-6:12-epoxy-7, 10-diacetoxypentadec-3-en-1-yne (4), along with the known 13-epilaurencienyne (3E) (5), have been isolated from the organic extract of the red alga Laurencia obtusa, collected in the Aegean Sea, Greece. The structures of the new natural products, as well as their relative stereochemistry, were established by means of spectral data analysis, including 2D NMR spectroscopic experiments. Some of the new metabolites exhibited significant insecticidal activity.     

Diterpenoids from the pericarp of Platycladus orientalis

Eight labdane-type diterpenes, 7beta,13S-dihydroxylabda-8(17),14-dien-19-oic acid (1), 12R,15-dihydroxylabda-8(17),13E-dien-19-oic acid (3c), 12R,15-dihydroxylabda-8(17),13Z-dien-19-oic acid (3d), 12R,13R,14S-trihydroxylabda-12,15-epoxy-8(17)-en-19-oic acid (4a), 12S,13S,14R-trihydroxylabda-12,15-epoxy-8(17)-en-19-oic acid (4b), 15-hydroxy-12-oxolabda-8(17),13E-dien-19-oic acid (5), 14R,15-dihydroxylabda-8(17),12Z-dien-19-oic acid (7a) and 14S,15-dihydroxylabda-8(17),12Z-dien-19-oic acid (7b), along with 20 known diterpenoids, were isolated from the pericarp of Platycladus orientalis. Their structures were unambiguously elucidated by NMR spectroscopic and single crystal X-ray diffraction analyses, as well as via chemical correlation conversion. NMR spectroscopic data of known isomers 8c and 8d were reported as a supplement to existing data.     

湖北旋覆花化学成分及抗结核活性研究

为进一步研究湖北旋覆花花序中的化学成分及抗结核活性。实验采用硅胶柱色谱、反相硅胶柱色谱以及制备型高相液相等方法进行了成分系统研究,肉汤二倍稀释法测定化合物的体外抗结核分支杆菌活性。从其花序中分离得到10个化合物。应用波谱学方法分别鉴定为:7,8-epoxy-9-(isobutyryloxy)thymolisobutyrate(1)、10-(2-methylbutyloxy)-8,9-epoxythymolisobutyrate(2)、stigmasterol(3)、ayapin(4)、ergolide(5)、5,10-epi-2,3-dihydroaromatin(6)、xanthalongin(7)、bigelovin(8)、carpesiolin(9)、aromaticin(10)。化合物1、2、5、6、8～10均为首次从该植物中分离得到。其中化合物5～10均为倍半萜类化合物。化合物5、6、8～10对结核分枝杆菌细胞株具有较好的抑制活性,最小抑制浓度MIC值分别为10.00、30.00、5.00、3.15、3.15μM,9和10的活性效果显著。     

ent-Labdane diterpenes from the aquatic plant Potamogeton pectinatus

Four new ent-labdane diterpenes were isolated from the freshwater aquatic plant Potamogeton pectinatus, together with two known furano-ent-labdanes. The new compounds were assigned the structures methyl-15,16-epoxy-12(R)-acetoxy- 8(17), 13(16),14-ent-labdatrien-19-oate,15,16-epoxy-12(R)-acetoxy-8(17), 13(16),14-ent-labdatrien-19-oic acid, 8(17),13-ent-labdadien-15 --> 16-lactone-19-oic acid and 16-hydroxy-8(17),13-ent-labdadien-15,16-olid-19-oic acid by spectroscopic means. Some of these labdanes showed a strong algicidal activity against Raphidocelis subcapitata.     

Synthesis and cytotoxicity evaluation of 6,11-dihydro-pyridazo- and 6,11-dihydro-pyrido[2,3-b]phenazine-6,11-diones

The 6,11-dihydro-pyridazo[2,3-b]phenazine-6,11-dione and 6,11-dihydro-pyrido[2,3-b]phenazine-6,11-dione derivatives were synthesized from 6,7-dichloro-5,8-phthalazinedione and 6,7-dichloro-5,8-quinolinedione, respectively, producing a series of new anticancer drugs. The cytotoxic activities of the prepared compounds were evaluated by a SRB (Sulforhodamine B) assay against the following tumor cell lines: A459 (human lung), SK-OV-3 (human ovarian), SK-MEL-2 (human melanoma), XF498 (human CNS), and HCT 15 (human colon). Almost all the derivatives of the 6,11-dihydro-pyridazo[2[,3-b]phenazine-6,11-dione and 6,11-dihydro-pyrido[2,3-b]phenazine-6,11-dione, tetracyclic heteroquinone analogues with four or three nitrogen atoms, exhibited excellent cytotoxicity on almost all the human tumor cell lines tested. Specifically, 6,11-dihydro-pyridazo[2,3-b]phenazine-6,11-dione (4a) exhibited potent activity against all the tumor cell lines, and in particular, its cytotoxic effect against HCT 15 (ED(50)=0.004 microg/mL) was 25 times greater than that of doxorubicin (ED(50)=0.093 microg/mL).     

Pinguisane and dimeric pinguisane-type sesquiterpenoids from the Japanese liverwort Porella acutifolia subsp. tosana

Two new pinguisane-type, three new Diels-Alder reaction-type dimeric pinguisane sesquiterpenoids and known sesqui and diterpenoids were isolated from the ether extract of the Japanese liverwort Porella acutifolia subsp. tosano. Their absolute stereostructures were established by a combination of extensive 2D-NMR, CD spectra, X-ray crystallographic analysis, modified Mosher's method and chemical correlation.     

Cancer chemopreventive activity of lupane- and oleanane-type triterpenoids from the cones of Liquidamber styraciflua

In a search for cancer chemopreventive agents from natural sources, four lupane-type and seven oleanane-type triterpenoids, and ten synthetic analogs were screened as potential anti-tumor promoters by using the in vitro short-term 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced Epstein-Barr virus early antigen (EBV-EA) activation assay. Among them, 25-acetoxy-3alpha-hydroxyolean-12-en-28-oic acid (1) and 3beta,25-epoxy-3alpha-hydroxylup-20(29)-en-28-oic acid (2) were examined for anti-tumor promoting activity in a two-stage carcinogenesis assay on mouse skin with 7,12-dimethylbenz[a]anthracene (DMBA) and TPA as promoter. 25-Acetoxy-3alpha-hydroxyolean-12-en-28-oic acid (1) and 3beta,25-epoxy-3alpha-hydroxylup-20(29)-en-28-oic acid (2) showed moderate inhibitory activities.     

Identification of 5 beta-cholestane-3 alpha,7 alpha,12 alpha,24,25,26-hexol in human urine

A new bile alcohol, 5 beta-cholestanehexol, was identified in the urine of healthy humans as the glucuronide. The bile alcohol glucuronide fraction was isolated by an ion exchange chromatography on piperidinohydroxypropyl Sephadex LH-20. After enzymatic hydrolysis, the bile alcohols were converted into trimethylsilyl ether derivatives and analyzed by a combination of gas-liquid chromatography and mass spectrometry. The major bile alcohol was 27-nor-5 beta-cholestane-3 alpha,7 alpha,12 alpha,24,25-pentol. As minor constituents the following C26 and C27 bile alcohols were identified: 27-nor-5 beta-cholestane-3 alpha,7 alpha,12 alpha,24,25,26-hexol, 5 beta-cholestane-3 alpha,7 alpha,12 alpha,24,25-pentol, 5 beta-cholestane-3 alpha,7 alpha,12 alpha,24,26-pentol, 5 beta-cholestane-3 alpha,7 alpha,12 alpha,25,26-pentol. In addition to these bile alcohols, a new bile alcohol was identified as a sixth component of the urinary bile alcohols. The structure was assigned as (24S)-5 beta-cholestane-3 alpha,7 alpha,12 alpha,24,25,26-hexol by the direct comparison of mass spectral data and chromatographic properties with synthetic standard. The average daily excretion of the new bile alcohol was 28.6 micrograms and 3.0% of the total bile alcohols. The presence of 27-nor-5 beta-cholestane-3 alpha,7 alpha,12 alpha,24,25-pentol and 27-nor-5 beta-cholestane-3 alpha,7 alpha,12 alpha,24,25,26-hexol suggests that 26-hydroxylation of 5 beta-cholestane-3 alpha,7 alpha,12 alpha,24,25-pentol is most likely for the biosynthesis of this new bile alcohol.