共查询到20条相似文献,搜索用时 31 毫秒
1.
ngel A. del Río‐Chvez Hugo A. García‐Gutirrez Luisa U. Romn‐Marín Lidia Beiza‐Granados Carlos M. Cerda‐García‐Rojas Pedro Joseph‐Nathan Juan D. Hernndez‐Hernndez 《Chirality》2019,31(11):934-946
The epimeric diterpenes (+)‐(1S,3E,7E,11S,12S)‐verticilla‐3,7‐dien‐12‐ol ( 1 ), isolated from Bursera suntui, and (+)‐(1S,3E,7E,11S,12R)‐verticilla‐3,7‐dien‐12‐ol ( 2 ), isolated from Bursera kerberi, gave the same Wagner‐Meerwein rearrangement product (?)‐(1E,4Z,8Z,11S,12R)‐phomacta‐1,(15)4,8‐triene ( 3 ). The Et2O:BF3‐induced transformations evidence that verticillenes and phomactanes, both containing the bicyclo[9.3.1]pentadecane skeleton, are biogenetically related through the verticillen‐12‐yl cation ( A + ), which also is a key intermediate in the biosynthetic pathways to generate antitumor taxanes. Molecular modeling using the Monte Carlo protocol, followed by density functional theory (DFT) geometry optimization employing the hybrid functionals B3LYP and B3PW91, both with the DGDZVP basis set, secured the configuration of 3 as followed from the good agreement between the calculated and experimental vibrational circular dichroism spectra. Similar DFT calculations allowed determining the absolute configuration of (+)‐(1R,4R,5R,8S,9S,11S,12R,15R)‐1,15:4,5:8,9‐triepoxyphomactane ( 9 ), which surprisingly derives from epoxidation of the second minimum energy conformer of 3 . 相似文献
2.
H.W. Gardner E.C. Nelson L.W. Tjarks R.E. England 《Chemistry and physics of lipids》1984,35(2):87-101
Acid treatment of (13S)-(9Z,11E)-13-hydroperoxy-9,11-octadecadienoic acid in tetrahydrofuran-water solvent afforded mainly (11R,12R,13S)-(Z)-12,13-epoxy-11-hydroxy-9-octadecenoic acid, diastereomeric (Z)-11,12,13-trihydroxy-9-octadecenoic acids and four isomers of (E)-9,12,13(9,10,13)-trihydroxy-10(11)-octadecenoic acid. Other minor products were oxooctadecadienoic, (E)-9(13)-hydroxy-13(9)-oxo-10(11)-octadecenoic and (E)-12-oxo-10-dodecenoic acids. A heterolytic mechanism for acid catalysis was indicated, even though most of the products characterized also have been observed as a result of homolytic decomposition of the hydroperoxide via an oxy radical. Most of the products found in this study have been observed as metabolites of (13S)-(9Z,11E)-13-hydroperoxy-9,11-octadecadenoic acid in biological systems, and analogous compounds have been reported as metabolites of (12S)-(5Z,8Z,10E, 14Z)-12-hydroperoxy-5,8,10,14-hydroperoxy-5,8,10,14-eicosatetraenoic acid in either blood platelets or lung tissue. 相似文献
3.
García-Gutiérrez HA Cerda-García-Rojas CM Hernández-Hernández JD Román-Marín LU Joseph-Nathan P 《Phytochemistry》2008,69(16):2844-2848
Medium polarity fractions of the hexane extracts of the stems of Bursera suntui afforded six previously known (1-6) and four hitherto unknown verticillane derivatives: (1S,3Z,7S,8S,11S,12S)-(+)-7,8-epoxyverticill-3-en-12,20-diol (7), (1S,3Z,7S,8S,11S,12S)-(+)-7,8-epoxyverticill-3-en-12,20-diol 20-acetate (8), (1S,3Z,7S,11S,12S)-(+)-verticilla-3,8(19)-dien-7,12,20-triol (9), and (1S,3Z,7S,11S,12S)-(+)-verticilla-3,8(19)-dien-7,12,20-triol 20-acetate (10). Acetylation of 9 and 10 yielded (1S,3Z,7S,11S,12S)-(+)-verticilla-3,8(19)-dien-7,12,20-triol 7,20-diacetate (11), while hydrolysis of 8 gave 7. The structures and stereochemistry of 7-11 were established by spectroscopic analyses, particularly by 1D and 2D NMR spectra and HRESIMS. The conformational preferences of 7-11 were studied by molecular mechanics modelling employing the Monte Carlo protocol followed by B3LYP/DGDZVP DFT calculation, thus supporting the observed 1H NMR NOESY cross peaks. 相似文献
4.
De-Li Luo Xiao-Hua Wang Ya-E Lei Chuan-Qi Lu Yan Lu Dao-Feng Chen Qi Wang 《化学与生物多样性》2023,20(3):e202200860
Cynasibirolide A ( 1 ), one new humulanolide sesquiterpene, together with four known analogs, asteriscanolide ( 2 ), (1S,8S)-8-hydroxyhumula-2Z,6E,9E-trien-1,12-olide ( 3 ), (1S,7R)-8-oxohumula-2Z,9E-dien-1,12-olide ( 4 ), and (+)-6,7,9,10-tetrahydroasteriscunolide ( 5 ) were isolated from the roots and rhizomes of Cynanchum acutum subsp. sibiricum. Their structures and configurations were elucidated by spectroscopic methods, including 2D-NMR techniques, and the structure of 1 was confirmed by single-crystal X-ray diffraction. All compounds were evaluated for their anti-complementary activity in vitro, and compound 3 exhibited anti-complement effect with CH50 value of 0.45 mM. 相似文献
5.
Triterpenoids and Flavonoids from the Leaves of Astragalus membranaceus and Their Inhibitory Effects on Nitric Oxide Production
下载免费PDF全文
![点击此处可从《化学与生物多样性》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Zhi‐Bin Wang Ya‐Dong Zhai Zhen‐Ping Ma Chun‐Juan Yang Rong Pan Jia‐Li Yu Qiu‐Hong Wang Bing‐You Yang Hai‐Xue Kuang 《化学与生物多样性》2015,12(10):1575-1584
Four new cycloartane triterpenes, named huangqiyegenins V and VI and huangqiyenins K and L ( 1 – 4 , resp.), together with nine known triterpenoids, 5 – 13 , and eight flavonoids, 14 – 21 , were isolated from a 70%‐EtOH extract of Astragalus membranaceus leaves. The structures of the new compounds were elucidated by detailed spectroscopic analyses, and the compounds were identified as (9β,11α,16β,20R,24S)‐11,16,25‐trihydroxy‐20,24‐epoxy‐9,19‐cyclolanostane‐3,6‐dione ( 1 ), (9β,16β,24S)‐16,24,25‐trihydroxy‐9,19‐cyclolanostane‐3,6‐dione ( 2 ), (3β,6α,9β,16β,20R,24R)‐16,25‐dihydroxy‐3‐(β‐D ‐xylopyranosyloxy)‐20,24‐epoxy‐9,19‐cyclolanostan‐6‐yl acetate ( 3 ), and (3β,6α,9β,16β,24E)‐26‐(β‐D ‐glucopyranosyloxy)‐16‐hydroxy‐3‐(β‐D ‐xylopyranosyloxy)‐9,19‐cyclolanost‐24‐en‐6‐yl acetate ( 4 ). All isolated compounds were evaluated for their inhibitory activities against LPS‐induced NO production in RAW264.7 macrophage cells. Compounds 1 – 3, 14, 15 , and 18 exhibited strong inhibition on LPS‐induced NO release by macrophages with IC50 values of 14.4–27.1 μM . 相似文献
6.
Five new and seven known mono‐sesquiterpenoids ( 1 – 5 and 6 – 12 , resp.) together with five known lindenane‐type disesquiterpenoids, 13 – 17 , were isolated from the whole plant of Chloranthus henryi. Based on spectroscopic methods, the new structures were established to be (5S,6R,8S,10R)‐6‐hydroxyeudesma‐4(15),7(11)‐diene‐12,8‐olide ( 1 ), 6α‐hydroxyeudesma‐4(15),7(11),8(9)‐triene‐12,8‐olide ( 2 ), 8,12‐epoxy‐1β‐hydroxyeudesma‐4(15),7,11‐trien‐6‐one ( 3 ), 12‐oxochloraniolide A ( 4 ), and (4α)‐8‐hydroxy‐12‐norcardina‐6,8,10‐trien‐11‐one ( 5 ), respectively. Among the isolates, compound 2 , zederone epoxide ( 8 ), spicachlorantin G ( 13 ), chloramultilide A ( 14 ), shizukaol B ( 15 ), and spicachlorantin B ( 17 ) showed significant anti‐neuroinflammatory effects by inhibiting nitric‐oxide (NO) production in lipopolysaccharide (LPS)‐stimulated murine BV‐2 microglial cells with relatively low cytotoxicity. 相似文献
7.
Ke Zan Xiao-Qing Chen Xing-Yun Chai Qing Wu Qiang Fu Si-Xiang Zhou Peng-Fei Tu 《Phytochemistry letters》2012,5(2):313-315
Two new eudesmane sesquiterpenoids artanoate (1) and eudesmanomolide (2) were isolated from the aerial parts of Artemisia anomala S. Moore. Their structures were elucidated as methyl (4R, 5S, 6S, 7S, 10R)-1-oxo-4, 6-dihydroxy-eudesma-2, 11 (13)-dien-12-oate (1) and (1R, 5R, 6R, 10R)-3, 13-diacetoxy-1-hydroxy-3, 7(11)-diene-12, 6-olide (2) on the basis of extensive spectroscopic analyses. Compound 1 showed cytotoxicity against HCT-8 cell lines with IC50 value of 9.13 μM, and compound 2 exhibited inhibitory activities against HCT-8 and A549 cell lines with IC50 values of 3.76 and 5.49 μM, respectively. 相似文献
8.
Lu Zhao Li-Ling Zhang Xian-Xian Miao Jia-Xin Li Hou-Wen Lin Wei-Hua Jiao 《化学与生物多样性》2021,18(10):e2100578
Chemical investigation of the marine sponge Dysidea avara, collected from the South China Sea, yielded 13 steroids, including nine new ( 1 – 9 ) and four known ( 10 – 13 ) ones. The new structures were elucidated as (3S,14R)-3,14-dihydroxycholesta-5,8-dien-7-one ( 1 ), (22E,24R)-7α-ethoxy-5α,6α-epoxyergosta-8(14),22-dien-3β-ol ( 2 ), 3β-hydroxy-7α-ethoxy-5α,6α-epoxy-8(14)-cholestene ( 3 ), 3β,5α-dihydroxy-6α-ethoxychofesta-7,9(11)-diene ( 4 ), 3β,5α-dihydroxy-6β-ethoxycholest-7-ene ( 5 ), (22E,24R)-24-ethoxy-3β,5α-dihydroxy-6β-ethoxyergosta-7,22-diene ( 6 ), (22E)-3β,5α-dihydroxy-6β-ethoxycholesta-7,22-diene ( 7 ), 24-ethoxy-3β,5α-dihydroxy-6β-ethoxycholest-7-ene ( 8 and 9 ), by extensive spectroscopic analyses, such as HR-ESI-MS, 1D and 2D NMR data. The absolute configuration of 1 was assigned by comparison the experimental ECD spectra with the calculated ones. Among the 13 metabolites, compounds 1 , 4 , 11 , 12 , and 13 showed NF-κB inhibitory activities in human HER-293 cells with IC50 values of 6.4, 18.7, 8.1, 9.6, and 7.5 μM, respectively. Preliminary structure−activity relationship analysis unveiled that the conjugated ketones or unsaturated double bonds might be the functional groups for the five active steroids. 相似文献
9.
Four New Tirucallane Triterpenoids from the Fruits of Melia azedarach and Their Cytotoxic Activities
下载免费PDF全文
![点击此处可从《化学与生物多样性》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Fang Zhou Xin‐Hua Ma Zhi‐Jun Li Wei Li Wei‐Min Zheng Zhi‐Biao Wang Xian‐Ming Zeng Kai‐Hui Sun Yong‐Hong Zhang 《化学与生物多样性》2016,13(12):1738-1746
Four new tirucallane triterpenoids, (21S,23R,24R)‐21,23‐epoxy‐21,24‐dihydroxy‐25‐methoxytirucall‐7‐en‐3‐one ( 2 ), (3S,21S,23R,24S)‐21,23‐epoxy‐21,25‐dimethoxytirucall‐7‐ene‐3,24‐diol ( 8 ), (21S,23R,24R)‐21,23‐epoxy‐24‐hydroxy‐21‐methoxytirucalla‐7,25‐dien‐3‐one ( 11 ), and (21S,23R,24R)‐21,23‐epoxy‐21,24‐dihydroxytirucalla‐7,25‐dien‐3‐one ( 12 ), along with 16 known analogues, 1 , 3 – 7 , 9 – 10 , and 13 – 20 , were isolated from the fruits of Melia azedarach. Their structures were elucidated by spectroscopic methods including 1D‐ and 2D‐NMR techniques and mass spectrometry. These compounds were evaluated for their cytotoxicities against HepG2 (liver), SGC7901 (stomach), K562 (leukemia), and HL60 (leukemia) cancer cell lines. Compound 20 exhibited potent cytotoxicity against HepG2 and SGC7901 cancer cells with the IC50 values of 6.9 and 6.9 μm , respectively. 相似文献
10.
Fang Li Ting-Ting Yan Ying-Ying Fu Nen-Ling Zhang Lei Wang Yan-Bing Zhang Juan Du Ji-Feng Liu 《化学与生物多样性》2021,18(4):e2001012
Chemical investigation of the ethanol extract of the branch and leaves of Illicium majus resulted in the isolation of four new phenylpropanoid glycosides ( 1 – 4 ) and one new phenolic glycoside ( 9 ), along with 13 known ones. Spectroscopic techniques were used to elucidate the structures of the new isolates such as 3-[(2R,3S)-7-hydroxy-2-(4-hydroxy-3-methoxyphenyl)-3-(hydroxymethyl)-2,3-dihydro-1-benzofuran-5-yl]propyl β-D-glucopyranoside ( 1 ), [(2R,3S)-7-hydroxy-2-(4-hydroxy-3-methoxyphenyl)-5-(3-hydroxypropyl)-2,3-dihydro-1-benzofuran-3-yl]methyl 2-O-α-L-rhamnopyranosyl-β-D-glucopyranoside ( 2 ), [(2R,3S)-7-hydroxy-2-(4-hydroxy-3-methoxyphenyl)-5-(3-hydroxypropyl)-2,3-dihydro-1-benzofuran-3-yl]methyl 2-O-α-L-rhamnopyranosyl-β-D-xylopyranoside ( 3 ), 3-[(2R,3S)-3-({[2-O-(4-O-acetyl-α-L-rhamnopyranosyl)-β-D-xylopyranosyl]oxy}methyl)-7-hydroxy-2-(4-hydroxy-3-methoxyphenyl)-2,3-dihydro-1-benzofuran-5-yl]propyl acetate ( 4 ), and 4-(2-hydroxyethyl)phenyl 3-O-β-D-glucopyranosyl-β-D-glucopyranoside ( 9 ). Free radical scavenging activities of the isolates were elucidated through the DPPH assay method. The most active compounds, 1-O-caffeoyl-β-D-glucopyranose ( 17 ) and soulieana acid 1 ( 18 ), exhibited moderate radical scavenging activities (IC50=37.7±4.4 μM and IC50=97.2±3.4 μM, respectively). The antibacterial activities of the isolates against Staphylococcus aureus and Escherichia coli were also assessed, and no activity was shown at the measured concentration (<32 μg/mL). 相似文献
11.
Xiang-Hai Cai Yuan-Yuan Wang Pei-Ji Zhao Yan Li Xiao-Dong Luo 《Phytochemistry》2010,71(8-9):1020-1024
Dolabellane diterpenoids, (1R,3E,7E,10S,11S,12R)-dolabella-3,7-dien-10,18-diol (1), (1R,3S,7E,11S,12R)-dolabella-4(16),7-dien-3,18-diol (2), (1R,7E,11S,12R)-18-hydroxydolabella-4(16),7-dien-3-one (3), (1R,3S,4S,7E,11S,12R)-3,4-epoxydolabella-7-en-18-ol (4), and (1R,3R,7E,11S,12R)-dolabella-4(16),7,18-trien-3-ol (5), were obtained from the ornamental plant Aglaia odorata. Their structures were characterized on the basis of spectroscopic analyses and further confirmed by X-ray diffraction. Compounds 1 and 5 showed weak cytotoxicity against the human myeloid leukemia HL-60, hepatocellular carcinoma SMMC-7721, and lung cancer A-549 cells. 相似文献
12.
Suspension cultured cells of Caragana chamlagu (Leguminosae) converted zerumbone (1) into zerumbone epoxide (2) as the intermediate, (2R,3R,7R)-2,3-epoxy-9-humulen-8-one (3) and (2R,3S,7R)-2,3-epoxy-9-humulen-8-one (4) as new sesquiterpenes in 11%, 36% and 21% yields, respectively. 相似文献
13.
Sex pheromone of the cloaked pug moth,Eupithecia abietaria (Lepidoptera: Geometridae), a pest of spruce cones
下载免费PDF全文
![点击此处可从《Journal of Applied Entomology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
H. L. Wang G. P. Svensson J. Jakobsson E. V. Jirle O. Rosenberg W. Francke O. Anderbrant J. G. Millar C. Löfstedt 《Journal of Applied Entomology》2015,139(5):352-360
The sex pheromone of the cloaked pug moth, Eupithecia abietaria Götze, an important cone‐feeding pest in spruce seed orchards in Europe, was investigated. Chemical and electrophysiological analyses of pheromone gland extracts of female moths and analogous analyses of synthetic hydrocarbons and epoxides of chain length C19 and C21 revealed (3Z,6Z,9Z)‐3,6,9‐nonadecatriene (3Z,6Z,9Z‐19:H) and 3Z,6Z‐cis‐9,10‐epoxynonadecadiene (3Z,6Z‐cis‐9,10‐epoxy‐19:H) as candidate pheromone components, which were found in a gland extract in a ratio of 95 : 5. In field trapping experiments, conspecific males were only attracted to a combination of 3Z,6Z,9Z‐19:H and the (9S,10R)‐enantiomer of 3Z,6Z‐cis‐9,10‐epoxy‐19:H. The (9R,10S)‐enantiomer was not attractive, which is in agreement with studies on other Eupithecia species, for which males have only been attracted by the (9S,10R)‐enantiomer of epoxides. Subsequent experiments showed that E. abietaria males were attracted to a wide range of ratios of the two active compounds and that trap catches increased with increasing dose of the binary blend. A two‐component bait containing 300 μg 3Z,6Z,9Z‐19:H and 33 μg of the (9S,10R)‐enantiomer of 3Z,6Z‐cis‐9,10‐epoxy‐19:H was efficient for monitoring E. abietaria in spruce seed orchards in southern Sweden, where this species has probably been overlooked as an important pest in the past. With sex pheromones recently identified for two other moths that are major pests on spruce cones, the spruce seed moth, Cydia strobilella L., and the spruce coneworm, Dioryctria abietella Denis & Schiffermüller, pheromone‐based monitoring can now be achieved for the whole guild of cone‐feeding moths in European spruce seed orchards. 相似文献
14.
Hnin Thanda Aung Alessio Porta Marco Clericuzio Yoshiaki Takaya Giovanni Vidari 《化学与生物多样性》2017,14(5)
Two new sterols 1 and 2 and five known ones 3 – 7 were isolated for the first time from the fruiting bodies of Cortinarius glaucopus. Their structures were established by 1‐ and 2D‐NMR spectra and HR‐FABS‐MS. The relative configuration of 1 was firmly determined by comparison of the observed 1H–1H couplings and NOESY correlations, with those predicted for the computed geometries of the conformers. Calculations were performed by means of DFT with the B3LYP functional at 6‐31 + G(d,p) level of theory, in CHCl3 as the solvent. The structures of the new ergosterol derivatives, called glaucoposterol A ( 1 ) and B ( 2 ), were thus established as (3S,5R,7R,10R,13R,17R,20S,22R,23R,24R)‐5,6‐epoxy‐3,7,23‐trihydroxystrophast‐8‐en‐14‐one and (22E,3S,5S,9S,10R,13R,17R,20R,24R)‐3,5‐dihydroxyergosta‐6,8(14),22‐trien‐15‐one, respectively. Moreover, the configuration of known strophasterol C ( 3 ) was determined as (3S,5R,6S,7R,10R,13R,17R,20S,22S,24R). Glaucoposterol A ( 1 ) and strophasterol C ( 3 ) represent the second finding in nature of steroids with the rare strophastane skeleton. 相似文献
15.
《Bioscience, biotechnology, and biochemistry》2013,77(4):882-886
The methanol extract of Ehretia dicksonii provided (10E,12Z,15Z)-9-hydroxy-10,12,15-octadecatrienoic acid methyl ester (1) which was isolated as an anti-inflammatory compound. Compound 1 suppressed 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced inflammation on mouse ears at a dose of 500 μg (the inhibitory effect (IE) was 43%). Linolenic acid methyl ester did not inhibit this inflammation at the same dose. However, the related compounds of 1, (9Z,11E)-13-hydroxy-9,11-octadecadienoic acid (5) and (9Z,11E)- 13-oxo-9,11-octadecadienoic acid (6), showed potent activity (IE500 μg of 63% and 79%, respectively). Compounds 1, 4 ((9Z,12Z,14E)-16-hydroxy-9,12,14-octadecatrienoic acid), 5 and 6 also showed inhibitory activity toward soybean lipoxygenase at a concentration of 10 μg/ml. 相似文献
16.
One solution to the global crisis of antibiotic resistance is the discovery of novel antimicrobial compounds for clinical
application. Marine organisms are an attractive and, as yet, relatively untapped resource of new natural products. Cell extracts
from the marine diatom, Phaeodactylum tricornutum, have antibacterial activity and the fatty acid, eicosapentaenoic acid (EPA), has been identified as one compound responsible
for this activity. During the isolation of EPA, it became apparent that the extracts contained further antibacterial compounds.
The present study was undertaken to isolate these additional antibacterial factors using silica column chromatography and
reverse-phase high-performance liquid chromatography. Two antibacterial fractions, each containing a pure compound, were isolated
and their chemical structures were investigated by mass spectrometry and nuclear magnetic resonance spectroscopy. The antibacterial
compounds were identified as the monounsaturated fatty acid (9Z)-hexadecenoic acid (palmitoleic acid; C16:1 n-7) and the relatively unusual polyunsaturated fatty acid (6Z, 9Z, 12Z)-hexadecatrienoic acid (HTA; C16:3 n-4). Both are active against Gram-positive bacteria with HTA further inhibitory to the
growth of the Gram-negative marine pathogen, Listonella anguillarum. Palmitoleic acid is active at micro-molar concentrations, kills bacteria rapidly, and is highly active against multidrug-resistant
Staphylococcus aureus. These free fatty acids warrant further investigation as a new potential therapy for drug-resistant infections. 相似文献
17.
A new sesquiterpenoid, 1 , and three new diterpenoids, 3 – 5 , along with five known compounds, 2 and 6 – 9 , were isolated from rhizomes of Alpinia japonica. The structures of the new compounds were determined as (1R,4R,6S,7S,9S)‐4α‐hydroxy‐1,9‐peroxybisabola‐2,10‐diene ( 1 ), methyl (12E)‐16‐oxolabda‐8(17),12‐dien‐15‐oate ( 3 ), (12R)‐15‐ethoxy‐12‐hydroxylabda‐8(17),13(14)‐dien‐16,15‐olide ( 4 ), and methyl (11E)‐14,15,16‐trinorlabda‐8(17),11‐dien‐13‐oate ( 5 ) by means of spectroscopic data. The absolute configurations at C(4) in 1 and C(12) in 4 were deduced from the circular dichroism (CD) data of the in situ‐formed [Rh2(CF3COO)4] complexes. Inhibitory effects of the isolates on NO production in lipopolysaccharide‐induced RAW264.7 macrophages were evaluated, and 2 – 4, 6 , and 7 were found to exhibit inhibitory activities with IC50 values between 14.6 and 34.3 μM . 相似文献
18.
《Chemistry and physics of lipids》1987,43(1):55-67
Treatment of methyl 13(S)-hydroperoxy-9(Z), 11(E)-octadecadienoate with vanadium oxyacetylacetonate led to the formation of two diastereometric α,β-epoxy alcohols, i.e. methyl 11(R), 12(R)-epoxy-13(S)-hydroxy-9(Z)-octadecenoate and methyl 11(S), 12(S)-epoxy-13(S)-hydroxy-9(Z)-octadecenoate. The epoxy alcohols underwent spontaneous hydrolysis into isomeric trihydroxyesters. The first mentioned epoxy alcohol afforded methyl 9(R), 12(S), 13(S)- and methyl 9(S), 12(S), 13(S)-trihydroxy-10(E)-octadecenoates as major hydrolysis products whereas the latter epoxy alcohol afforded methyl 9(R), 12(R), 13(S)- and methyl 9(S), 12(R)-13(S)-trihydroxy-10(E)-octadecenoates as major compounds. Smaller amounts of diastereomeric methyl 11,12,13-trihydroxy-9-octadecenoates were also formed from both epoxy alcohols. The vanadium-catalyzed conversion of 13(S)-hydroperoxy-9(Z),11(E)-octadecadienoic acid (13(S)HPOD) (methyl ester) into α,β-epoxy alcohols and their further conversion into trihydroxy derivatives offers a model system for similar transformations of certain poly-unsaturated fatty acids recently described in the fungus, Saprolegnia parasitica. 相似文献
19.
Shan‐Yu Lin Horng‐Huey Ko Shiow‐Ju Lee Hsun‐Shuo Chang Chu‐Hung Lin Ih‐Sheng Chen 《化学与生物多样性》2015,12(7):1057-1067
Bioassay‐guided fractionation of the root of Machilus obovatifolia led to the isolation of four new lignans, epihenricine B ( 1 ), threo‐(7′R,8′R) and threo‐(7′S,8′S)‐methylmachilusol D ( 2 and 3 ), and isofragransol A ( 4 ), along with 23 known compounds. The compounds were obtained as isomeric mixtures (i.e., 2 / 3 and 4 / 20 , resp.). The structures were elucidated by spectral analyses. Among the isolates, 1 , licarin A ( 12 ), guaiacin ( 14 ), (±)‐syringaresinol ( 21 ), and (?)‐epicatechin ( 23 ) showed ABTS (=2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) cation radical‐scavenging activity, with SC50 values of 11.7±0.5, 12.3±1.1, 11.0±0.1, 10.6±0.3, and 9.5±0.2 μM in 20 min, respectively. In addition, kachirachirol B ( 17 ) showed cytotoxicity against the NCI‐H460 cell line with an IC50 value of 3.1 μg/ml. 相似文献
20.
《Bioscience, biotechnology, and biochemistry》2013,77(6):1354-1357
Stereoselective synthesis of a promising flower-inducing 9,10-ketol octadecadienoic acid (KODA) analog, (9R,12S,13R,15Z)-9-hydroxy-12,13-methylene-10-oxooctadec-15-enoic acid, was designed to obtain the desired stereoisomer via coupling between chiral sulfone and aldehyde segments. A known chiral cyclopropane derivative was converted to the sulfone segment via carbon-chain elongation and sulfonylation. Dec-9-en-1-ol was converted to the aldehyde segment, whose C-9 configuration was introduced by Sharpless asymmetric dihydroxylation. Coupling of the both segments and subsequent assembly gave the desired (9R,12S,13R,15Z)-analog. The (9S,12S,13R,15Z)-analog was also synthesized by using the enatiomeric aldehyde segment. This strategy made it possible to synthesize the remaining stereoisomeric analogs. 相似文献