Minor sesquiterpenes with new carbon skeletons from the brown alga Dictyopteris divaricata

Five minor sesquiterpenes (1-5) with two novel carbon skeletons, together with a minor new oplopane sesquiterpene (6), have been isolated from the brown alga Dictyopteris divaricata. By means of spectroscopic data including IR, HRMS, 1D and 2D NMR, and CD, their structures including absolute configurations were assigned as (+)-(1R,5S,6S,9R)-3-acetyl-1-hydroxy-6-isopropyl-9-methylbicyclo[4.3.0]non-3-ene (1), (+)-(1R,3S,4S,5R,6S,9R)-3-acetyl-1,4-dihydroxy-6-isopropyl-9-methylbicyclo[4.3.0]nonane (2), (+)-(1R,3R,4R,5R,6S,9R)-3-acetyl-1,4-dihydroxy-6-isopropyl-9-methylbicyclo[4.3.0]nonane (3), (+)-(1S,2R,6S,9R)-1-hydroxy-2-(1-hydroxyethyl)-6-isopropyl-9-methylbicyclo[4.3.0]non-4-en-3-one (4), (-)-(5S,6R,9S)-2-acetyl-5-hydroxy-6-isopropyl-9-methylbicyclo[4.3.0]non-1-en-3-one (5), and (-)-(1S,6S,9R)-4-acetyl-1-hydroxy-6-isopropyl-9-methylbicyclo[4.3.0]non-4-en-3-one (6). Biogenetically, the carbon skeletons of 1-6 may be derived from the co-occurring cadinane skeleton by different ring contraction rearrangements. Compounds 1-6 were inactive (IC(50) > 10 mug/mL) against several human cancer cell lines.     

Cadinane sesquiterpenes from the brown alga Dictyopteris divaricata

Seven new cadinane sesquiterpenes, (-)-(1R,6S,7S,10R)-1-hydroxycadinan-3-en-5-one (1), (+)-(1R,5S,6R,7S, 10R)-cadinan-3-ene-1,5-diol (2), (+)-(1R,5R,6R,7S,10R)-cadinan-3-ene-1,5-diol (3), (+)-(1R,5S,6R,7S,10R)-cadinan-4(11)-ene-1,5-diol (4), (+)-(1R,5R,6R,7R,10R)-cadinan-4(11)-ene-1,5,12-triol (5), (-)-(1R,4R,5S,6R,7S, 10R)-cadinan-1,4,5-triol (6), and (-)-(1R,6R,7S,10R)-11-oxocadinan-4-en-1-ol (7), together with nine known compounds were isolated from the brown alga Dictyopteris divaricata. The structures of the new natural products, as well as their absolute configuration, were established by means of spectroscopic data including IR, HRMS, 1D and 2D NMR, single-crystal X-ray diffraction, and CD. All compounds were inactive against several human cancer cell lines including lung adenocarcinoma (A549), stomach cancer (BGC-823), breast cancer (MCF-7), hepatoma (Bel7402), and colon cancer (HCT-8) cell lines.     

New skeletal sesquiterpenoids, caprariolides A-D, from Capraria biflora and their insecticidal activity

Four structurally novel isomeric sesquiterpenes have been isolated from the aerial parts of Capraria biflora. Caprariolides A (1), B (2), C (3), and D (4) have been determined by NMR spectroscopy experiments to be the (3S,5S,9R), (3R,5S,9R), (3R,5R,9R), and (3S,5R, 9R) isomers of 7-(furan-3'-yl)-3,9-dimethyl-1-oxaspiro[4. 5]dec-6-en-2-one, respectively. Both 1 and 2 were found to exhibit insecticidal activity against adult Cylas formicarius elegantulus, one of the most destructive insect pests of the sweet potato, Ipomoea sp.     

Absolute configuration of lippifoliane and africanane derivatives

The absolute configuration of naturally occurring lippifoliane derivatives isolated from the widely used plant Lippia integrifolia was assigned by analysis of the circular dichroism data in combination with density functional theory minimum energy molecular models of (1S,4R,6S,9S,10R)-lippifolian-1-ol-5-one (1), (4R,9S,10R)-lippifoli-1(6)-en-5-one (2), and (4S,9S,10R)-lippifoli-1(6)-en-4-ol-5-one (3) and application of the octant rule for saturated ketone 1 and the helicity rules for alpha,beta-unsaturated ketones 2 and 3. The results were reinforced by the anomalous dispersion effect observed in the X-ray diffraction analysis of (4S,9S,10R)-4,10,11-tribromo-10,11-seco-lippifoli-1(6)-en-5-one (4) prepared from 2. The biogenetic relationships between lippifolianes 1-3 and africanane derivatives 7-9 and 13 isolated from the same species, together with chiroptical data for africananes isolated from the Hepaticae family, complete a stereochemical scenario in relation to the absolute configuration of africananes from L. integrifolia.     

Iridoids from Crescentia alata

Four new 11-nor-iridoids, 6beta,7beta,8alpha,10-tetrahydroxy-cis-2-oxabicyclo[4.3.0]nonan-3-one (1), 6beta,7beta,8alpha,10-tetra-p-hydroxybenzoyl-cis-2-oxabicyclo[4.3.0]nonan-3-one (2), 1beta,6beta,7alpha,8alpha,10-pentahydroxy-cis-2-oxabicyclo[4.3.0]nonane (3), and 6beta-hydroxy-2-oxabicyclo[4.3.0]Delta8-9-nonen-1-one (4), were isolated from the pulp of the fruits of Crescentia alata. Although a limited number of Crescentia species have been studied chemically, iridoids lacking C-11 have been isolated from the fruits of these species, and the isolation of compounds 1-4 from C. alata is in accordance with the constituents of the species previously analyzed. The structures of these compounds were established on the basis of IR, UV, 1H and 13C NMR, DEPT, COSY, HSQC, HMBC, MS, and X-ray data.     

Phelligridins C-F: cytotoxic pyrano[4,3-c][2]benzopyran-1,6-dione and furo[3,2-c]pyran-4-one derivatives from the fungus Phellinus igniarius

Three unique pyrano[4,3-c][2]benzopyran-1,6-dione derivatives and a new furo[3,2-c]pyran-4-one, named phelligridins C-F (2-5), together with hispolon (8), (E)-4-(3,4-dihydroxyphenyl)but-3-en-2-one (9), 4-hydroxybenzaldehyde, protocatechualdehyde, syringic acid, protocatechuic acid, caffeic acid, isoergosterone, and octadecyl ferulate were isolated and identified from the ethanolic extract of Phellinus igniarius. Their structures were determined by spectroscopic methods including IR, MS, and 1D and 2D NMR experiments. The structures of the new compounds were characterized as 3-(4-hydroxystyryl)-8,9-dihydroxypyrano[4,3-c]isochromene-4-one (2), 3-(3,4-hydroxystyryl)-8,9-dihydroxypyrano[4,3-c]isochromene-4-one (3), 8,9-dihydroxy-3-[5',6'-dihydroxy-5' '-methyl-3' '-oxo-spiro[fural-2' '(3' 'H),1'-indene]-2'-yl]-1H,6H-pyrano[4,3-c][2]benzopyran-1,6-dione (4), and (3Z)-3-(3,4-dihydroxybenzylidene)-6-(3,4-dihydroxystyryl)-2,3-dihydro-2-methoxy-2-(2-oxo-propyl)furo[3,2-c]pyran-4-one (5), respectively. Some compounds including 2 and 3 showed in vitro selective cytotoxicity against a human lung cancer cell line (A549) and a liver cancer cell line (Bel7402). Possible biogenetic sequences to the formation of 1-9 are postulated.     

Microbial transformation and butyrylcholinesterase inhibitory activity of (-)-caryophyllene oxide and its derivatives

Microbial transformation of the sesquiterpene (-)-caryophyllene oxide (1) [(1R,4R,5R,9S)-4,5-epoxycaryophyllan-8(13)-ene] by a number of fungi, using a standard two-stage fermentation technique, has afforded as products (1R,4R,5R,9S)-4,5-dihydroxycaryophyllan-8(13)-ene (2), (1S,4R,5R,8S,9S)-clovane-5,9-diol (3), (1R,4R,5R,9S,11R)-4,5-epoxycaryophyllan-8(13)-en-15-ol (4), (1R,4R,5R,9S,11S)-4,5-epoxycaryophyllan-8(13)-en-14-ol (5), (1R,2S,4R,5R,9S)-4,5-epoxy-13-norcaryophyllan-8-one (6), (1R,4R,5R,8S,9S)-4,5-epoxycaryophyllan-13-ol (7), (1R,4R,5R,8S, 9S,13S)-caryolane-5,8,13-triol (8), (1R,3R,4R,5R,8S,9S)-4,5-epoxycaryophyllan-3,13-diol (9), and (1S,4R,5R,8S,9S)-clovane-5,9,12-triol (10). Metabolites 6 and 8-10 were found to be new compounds, as deduced on the basis of spectroscopic techniques. Compounds 1-10 were evaluated for butyrylcholinesterase inhibitory activity, and compound 5 exhibited an IC50 value of 10.9 +/- 0.2 microM.     

Cycloartane glycosides from Sutherlandia frutescens

Four new cycloartane glycosides, sutherlandiosides A-D (1-4), were isolated from the South African folk medicine Sutherlandia frutescens and their structures established by spectroscopic methods and X-ray crystallography as 1 S,3 R,24S,25-tetrahydroxy-7S,10S-epoxy-9,10- seco-9,19-cyclolanost-9(11)-ene 25-O-beta-D-glucopyranoside (1), 3R,7S,24S,25-tetrahydroxycycloartan-1-one 25-O-beta-D-glucopyranoside (2), 3R,24S,25-trihydroxycycloartane-1,11-dione 25-O-beta-D-glucopyranoside (3), and 7S,24S,25-trihydroxycycloart-2-en-1-one 25-O-beta-D-glucoyranoside (4). Compound 1 represents the first secocycloartane skeleton possessing a 7,10-oxygen bridge. Compounds 2- 4 are also the first examples of naturally occurring cycloartanes with a C-1 ketone functionality. Biosynthetic considerations and chemical evidence suggest that the presence of the C-1 ketone in 2 may facilitate the ring opening of the strained cyclopropane system.     

Preparation of moreliane-derived volatile sesquiterpenes

A series of six volatile sesquiterpenes (9-13 and 15) was prepared by thioketalization of (4R,5S,9S,10S,11S)-morel-2-en-1,7-dione (2) and of (4R,5S,7R,9R,11R)-moreli-2,10-dien-7-ol-1-one (3), followed by Raney-nickel desulfurization. The structures of the new substances were determined by 1D and 2D NMR including COSY, NOESY, HSQC, and HMBC experiments. The geometry of (3S,4R,5R,9S,10R,11S)-morelian-7-one (11), which exhibited an intense woody odor, was calculated by density functional theory at the B3LYP/6-31G level.     

红藻扇形叉枝藻中的降碳倍半萜及其衍生物

目的：对红藻扇形叉枝藻Gymnogongrus flabelliformis进行化学成分研究。方法：利用正相和反相硅胶柱色谱、Sephadex LH-20凝胶柱色谱和反相HPLC等手段进行分离纯化,借助MS,1D和2D NMR等波谱方法鉴定化合物结构；通过MTT法对分离鉴定的单体化合物在人肺癌细胞株(A549)、人肝癌细胞株(Bel 7402)、人胃癌细胞株(BGC 823)、人结肠癌细胞株(HCT-8)和人卵巢癌细胞株(A2780)上进行肿瘤细胞毒活性筛选。结果：从红藻扇形叉枝藻中分离得到5个降碳倍半萜类化合物,分别鉴定为(3S,6R,7E)-(+)-3-hydroxyl-4,7-megastigmadien-9-one(1),(3S,5R,6S,7E)-(-)-3-hydroxy-5,6-epoxy-7-megastig-mene-9-one(2),(3S,5S,6R,7E)-(+)3-hydroxy-5,6-epoxy-7-megastigmene-9-one(3),dehydrovomifoliol(4)和(3R)-(-)-4-［(2R,4S)-4-acetoxy-2-hydroxy-2,6,6-trimethylcyclohexylidene］-3-buten-2-one(5)。结论：以上化合物均为首次从该属海藻中分离得到,其中化合物1为新天然产物。细胞毒活性试验结果显示所有化合物在10 μg·mL^-1均无明显细胞毒活性。     

New dihydrophenanthrene and phenyldihydroisocoumarin constituents of Trema orientalis.

In the course of the chemical investigation of extracts of the trunk bark and root bark of Trema orientalis, three new compounds were isolated, namely, (9S*,10S*)-3-[7-(3,10-dihydroxy-9-hydroxymethyl-2,5-dimethoxy)-9,10-dihydrophenanthrenyl]propenal (1), (9S*,10S*)-3-[7-(5-O-beta-glucopyranosyl-10-hydroxy-9-hydroxymethyl-2,6-dimethoxy)-9,10-dihydrophenanthrenyl]propenal (2), and (3R*,3aR*,4R*,5S*)-6-O-alpha-arabinopyranosyl-8-hydroxy-3-(4-hydroxyphenyl)-4-(4-hydroxyphenyl)-5-(3,5-dihydroxyphenyl)-3,3a-dihydrocyclopenta[1,2,3-de]isobenzopyran-1-one (3, orientoside A). The structures of 1-3 were determined by spectral methods.     

Daucane sesquiterpenes from Ferula hermonis

The dried roots of Ferula hermonis yielded three new daucanes, (1R,4R)-4-hydroxydauca-7-ene-6-one (1), (1R,4R)-4-hydroxydauca-7-ene-6,9-dione (2), and (1R,3S,8S)-3-ethoxy-8-angeloyloxydauca-4-en-9-one (3), together with the three known sesquiterpenes, ferutinin, teferidin, and (+)-alpha-bisabolol. The structures of compounds 1-3 were elucidated on the basis of spectroscopic evidence. The effect of these compounds on the proliferation of estrogen-dependent MCF-7 cells was evaluated, and it was found that compounds 1 and 3 exhibited proliferative activity, whereas 2 showed an antiproliferative effect.     

Three new sesquiterpenes from the red alga Laurencia perforata

From the lipophilic extract of the red alga Laurencia perforata three new sesquiterpenes, (1S,2S,4S,5S, 6S,8R)-4-hydroxy-2,5,6-trimethyl-11-methylenetricyclo[6.2.1.0(1,6)]undecan-3-one (1, 4-hydroxy-1,8-epi-isotenerone), (3R,4R,4aR,9R)-3,9-dihydroxy-1,4,4a,7-tetramethyl-3,4,4a,5,8,9-hexahydro-2H-benzo[a]cyclohepten-2-one (9-hydroxy-3-epi-perforenone A, 2), and 3-epi-perforenone A (3), were isolated. The structures of all isolates were determined from their spectroscopic data (NMR, MS, IR, UV). Unusual for a species of this algal genus was the apparent absence of halogenated compounds.     

Brominated labdane-type diterpenoids from an Okinawan Laurencia sp

From an unidentified species of Laurencia collected from Okinawan waters two novel brominated metabolites, 1 and 2, along with known halogenated compounds, 2,10-dibromo-3-chloro-alpha-chamigrene (3) and microcladallene A (4), were isolated and identified. The structures of these new compounds were established as ent-labdane-type bromoditerpenes, (1S,3R,5S,6S,8S,9S,10R,13R)-1-acetoxy-3-bromo-6-hydroxy-8,13-epoxy-labd-14-ene (1) and (3R,5S,6S,8S,9S,10R,13R)-3-bromo-6-hydroxy-8,13-epoxylabd-14-en-1-one (2), by interpretation of their spectroscopic data as well as by X-ray crystallographic analysis.     

Antiplatelet activities of newly synthesized derivatives of piperlongumine

Piperlongumine, a pyridone alkaloid isolated from Piper longum L., exhibited a potential inhibitory effect on washed rabbit platelet aggregation induced by collagen, arachidonic acid (AA) and platelet activating factor (PAF), without any inhibitory effect on that induced by thrombin. Piperlongumine was used as a lead compound for the synthesis of new antiplatelet agents. Seven synthetic compounds were newly synthesized from 3,4,5-trimethoxycinnamic acid (TMCA). They were 1-piperidin-1-yl-3-(3,4,5-trimethoxy-phenyl)prop-2-en-1-one (1'), 1-morpholin-4-yl-3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (2'), 1-(3,5-dimethylpiperidin-1-yl)-3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (3'), 1-(2-methylpiperidin-1-yl)-3-(3,4,5-tri-methoxyphenyl)prop-2-en-1-one (4'), 1-(3-hydroxypiperidin-1-yl)-3-(3,4,5-trimethoxyphenyl)- prop-2-en-1-one (5'), 1-[3-(3,4,5-tri-methoxyphenyl) acryloyl]-piperidin-2-one (6') and ethyl 1-[3-(3,4,5-trimethoxyphenyl)-acryloyl]piperidine-4-carboxylate (7'). Among those seven synthetic derivatives, 1-(3,5-dimethylpiperidin-1-yl)-3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (3') had the most inhibitory effect on platelet aggregation induced by collagen, AA and PAF.     

Cytotoxic constituents of the roots of Ekmanianthe longiflora

Bioactivity-directed fractionation of the CHCl(3) extract of the roots of Ekmanianthe longiflora resulted in the isolation of three new natural products, (2R,3R,4R)-3,4-dihydro-3, 4-dihydroxy-2-(3-methyl-2-butenyl)-1(2H)-naphthalenone (1), (2S,3R, 4R)-3,4-dihydro-3, 4-dihydroxy-2-(3-methyl-2-butenyl)-1(2H)-naphthalenone (2), and (2R, 3aR,9R,9aR)-9-hydroxy-2-(1-hydroxy-1-methylethyl)-2,3,3a,4,9 , 9a-hexahydro-naphtho[2,3-b]furan-4-one (3), together with the known compounds 2-(1-hydroxyethyl)naphtho[2,3-b]furan-4,9-quinone (4), 2-acetylnaphtho[2,3-b]furan-4,9-quinone (5), dehydro-iso-alpha-lapachone (6), alpha-lapachone (7), catalponol, and epi-catalponol. The structures of 1-3 were determined using a combination of NMR spectroscopic techniques, and the absolute configurations of compounds 1 and 2 were obtained using Mosher ester methodology. Compounds 4-6 showed significant cytotoxicity in a panel of human cancer cells. alpha-Lapachone (7) exhibited only marginal activity, and catalponol and epi-catalponol were inactive in this regard. When tested at 72 mg/kg/injection in an in vivo mouse P-388 leukemia system, compound 4 was inactive (110% T/C).     

三角叶凤毛菊中类异戊二烯和苯丙素类化学成分

目的:研究菊科药用植物三角叶凤毛菊Saussurea deltoidea的化学成分.方法:利用正/反相硅胶柱层析色谱、凝胶分子筛色谱、HPLC等色谱方法进行化合物的分离,利用波谱学方法鉴定化合物结构.结果:从三角叶凤毛菊中分离出10个化合物,其结构分别鉴定为(3R,6R,7E)-3-hydroxy-4,7 -megastigmadien-9 -one(1),(3S,5R,6S,7E)-5,6-epoxy-3-hydroxy-7-megastigmen-9-one (2),3 -h ydroxy-β-damascone(3),S-(+)-dehydrovomifoliol(4),megastigman-5 -ene-3β,9R-diol(5),coniferaldehyde(6),β-hydroxypropiovanillone (7),3-hydroxy-1- (4-hydroxy-3,5-dimethoxyphenyl)-1-propanone (8),dihydrosyringenin(9),4-[(1S)-3-hydroxy-1-methoxypropyl]-2,6-dimenthoxyphenol( 10).结论:化合物1～10均是首次从该植物中分离得到.     

柿叶化学成分研究(Ⅱ)

目的 研究柿叶的化学成分.方法 利用溶剂萃取、聚酰胺色谱、高效液相色谱等方法对柿叶进行分离和纯化,并根据波谱数据分析(1H,13C-NMR和MS)及文献比对鉴定化合物结构.结果 从柿叶中分离得到8个化合物,分别鉴定为(6R,9R)-3-oxo-a-ionol[3-D-glucopyranoside(1);corchoi...     

C-15-functionalized eudesmanolides from Mikania campanulata

The aerial parts of Mikania campanulata Gardner afforded the nine new eudesmanolides (1S,4S,5S,6S,7S,10R)-1-hydroxy-15-acetoxyeudesm-11(13)-en-6,12-olide (1), (1S,4S,5S,6S,7S,10R)-1,4-dihydroxy-15-acetoxyeudesm-11(13)-en-6,12-olide (2), (1R,4S,5S,6S,7S,10R)-1,4-dihydroxy-15-acetoxyeudesm-11(13)-en-6,12-olide (3), (1R,4S,5S,6S,7S,10R)-1-hydroxy-4,15-diacetoxyeudesm-11(13)-en-6,12-olide (4), (1S,4R,5S,6S,7S,10R)-1,15-diacetoxy-4-hydroxyeudesm-11(13)-en-6,12-olide (5), (1S,5S,6S,7S,10R)-1-hydroxy-15-acetoxyeudesma-4(15),11(13)-dien-6,12-olide (6), (1S,5S,6S,7S,10R)-1,15-dihydroxyeudesma-3,11(13)-dien-6,12-olide (7a), (1S,2R,5S,6S,7S,10R)-1,2,15-trihydroxyeudesma-3,11(13)-dien-6,12-olide (8a), and (1R,6S,7S,10R)-1,15-dihydroxyeudesma-4,11(13)-dien-6,12-olide (9a), among which the last three were characterized as their corresponding peracetates (7b-9b). The structures of 1-6 and 7b-9b were elucidated using 1D and 2D NMR measurements, while that of major constituent 1 was confirmed by single-crystal X-ray diffraction analysis, and its absolute configuration evidenced from vibrational circular dichroism measurements, which were compared to results obtained from density functional theory calculations. The chemistry of the large genus Mikania is briefly analyzed.     

Terpenoids from the roots and rhizomes of Nardostachys chinensis

A new diterpene, 10-isopropyl-2,2,6-trimethyl-2,3,4,5-tetrahydronaphtha[1,8-bc]oxocine-5,11-diol (1), and a new monoterpene, 6-hydroxy-7-(hydroxymethyl)-4-methylenehexahydrocyclopenta[c]pyran-1(3H)-one, together with four known sesquiterpenes, delta1(10)-aristolene-9beta-ol, debilon, nardosinone, and kanshone A, were isolated from the roots of Nardostachys chinensis. The structures of the new compounds were established on the basis of their spectroscopic data, and the structure of 1 was confirmed by X-ray crystallographic analysis.