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1.
(1S,2R,6R,7R)-4-Phenyl-3,10-dioxa-5-azatricyclo[5.2.1.02,6]dec-4-en-9-one ((+)- 5 ) obtained in 6 steps from the Diels-Alder adduct of furan to 1-cyanovinyl (1S)-camphanate ((+)- 3 ) was reduced to the corresponding endo-alcohol (?)- 6 the treatment of which with HBr/AcOH provided (?)-(3aS,4S,6R,7S,7aR)-4β-bromo-3aβ,4,5,6,7,7aβ-hexahydro-2-phenyl-1,3-benzoxazole-6β,7α-diyl diacetate ((?)- 17 ). Elimination of HBr with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and acidic hydrolysis furnished (?)-(1R,2S,3R,4R)-4-aminocyclohex-5-ene-1,2,3-triol ( ? (?)-conduramine C1;(?)- 1 ).  相似文献   

2.
Nine compounds were isolated from Nocardia sp. YIM 64630, and their structures were elucidated as 5′-O-acetyl-2′-deoxyuridine (1), 22E,24R-5α,6α-epoxyergosta-8(14),22-diene-3β,7α-diol (2), 22E,24R-5α,6α-epoxyergosta-8,22-diene-3β,7α-diol (3), 22E,24R-ergosta-7,22-diene-3β,5α,6β-triol (4), 5α,8α-epidioxyergosta-6,22-dien-3β-ol (5), 4′,5,6-trihydroxy-7-methoxyisoflavone (6), 2,4,4′-trihydroxy-deoxybenzoin (7), methyl [4-hydroxyphenyl]acetate (8) and daidzein by extensive spectroscopic analyses. Compound 1 was isolated from natural resources for the first time. The antimicrobial and antioxidant activities of compounds 18 were investigated.  相似文献   

3.
Five new acyclic monoterpene glycosides 1 – 5 were isolated from the leaves of Viburnum orientale (Caprifoliaceae). Anatolioside ( 1 ) is a monoterpene diglycoside and its structure was elucidated as linalo-6-yl 2′-O-(α-L -rhamnopyranosyl)β-D -glucopyranoside (arbitrary numbering of linalool moiety). Compounds 2 – 5 are all derivatives of 1 , containing additional monoterpene and sugar units, connected by ester and glycoside bonds. Their structures were established as linalo-6-yl O-[(2E,6R)-6-hydroxy-2, 6-dimethylocta-2,7-dienoyl]-(1? → 4″)-O-α-L -rhamnopyranosyl-(1″? → 2″″)-β-D -glucopyranoside ( = anatolioside A; 2 ), linalo-6-yl O-β-D -glucopyranosyl-(1? → 6?)-O-[(2E,6R)-6-hydroxy-2,6-dimethylocta-2,7-dienoyl]-(1? → 4″)-O-α-L -rhamnopyranosyl-(1″ → 2′)–β-D -glucopyranoside ( = anatolioside B; 3 ), linalo-6-yl O-β-D ribo-hexopyranos-3-ulosyl-(1′? → 6?)-O-[(2E,6R)-6-hydroxy-2,6-dimethylocta-2,7-dienoyl]-(1? → 4″)-O-α-L -rhamnopyranosyl-(1″ → 2′)-β-D -glucopyranoside ( = anatolioside C; 4 ) and linalo-6-yl O-[(2E, 6R)-6-hydroxy-2,6-dimethylocta-2,7-dienoyl]-(1″? → 2″″)-O-β-D -glucopyranosly-(1″″ → 6?)-O-[(2E,6R)-6-hydroxy-2,6-dimethylocta-2,7-dienoyl]-(1? → 4″)-O-α-L -rhamnopyranosyl(1″ → 2′)-β-D -glucopyranoside ( = anatolioside D ; 5 ). The structure determinations were based on spectroscopic and chemical methods (acid and alkaline hydrolysis, acetylation and methylation).  相似文献   

4.
Chemical examination of a marine sponge Xestospongia sp. resulted in the isolation of 20 sterol derivatives ( 1 – 20 ), including eight new sterols namely aragusterols J – L ( 1 – 3 ), (5α,7α,12β,22E)‐7,12,18‐trihydroxystigmast‐22‐en‐3‐one ( 4 ), (5α,7α,12β,24R)‐ and (5α,7α,12β,24S)‐7,12,20‐trihydroxystigmastan‐3‐one ( 5 / 6 ), and (5α,7α,12β,22E,24R)‐ and (5α,7α,12β,22E,24S)‐7,12,20‐trihydroxyergost‐22‐en‐3‐one ( 7 / 8 ). The structures of new compounds were determined through extensive spectroscopic analyses and chemical conversion. The sterol diversity was mainly characterized by the presence of a cyclopropane unit at side chain, while compound 4 with 18‐hydroxymethyl group was found in stigmasterol family for the first time. Cytotoxic test revealed the inhibitory effects of compounds 1 , 4 , and 17 against human leukemia cell line K562 with IC50 values of 18.3, 24.1, and 34.3 μm , respectively.  相似文献   

5.
New 2‐(aminomethyl)‐5‐(hydroxymethyl)pyrrolidine‐3,4‐diol derivatives were synthesized from (5S)‐5‐[(trityloxy)methyl]pyrrolidin‐2‐one ( 6 ) (Schemes 1 and 2) and their inhibitory activities toward 25 glycosidases assayed (Table). The influence of the configuration of the pyrrolidine ring on glycosidase inhibition was evaluated. (2R,3R,4S,5R)‐2‐[(benzylamino)methyl]‐5‐(hydroxymethyl)pyrrolidine‐3,4‐diol ((+)‐ 21 ) was found to be a good and selective inhibitor of α‐mannosidase from jack bean (Ki=1.2 μM ) and from almond (Ki=1.0 μM ). Selectivity was lost for the non‐benzylated derivative (2R,3R,4S,5R)‐2‐(aminomethyl)‐5‐(hydroxymethyl)pyrrolidine‐3,4‐diol ((+)‐ 22 ) which inhibited α‐galactosidases, β‐galactosidases, β‐glucosidases, and αN‐acetylgalactosaminidase as well.  相似文献   

6.
Nine new sesquiterpenes, i.e., dendronobilins A–I ( 1 – 9 ), with copacamphane‐type ( 1 ), picrotoxane‐type ( 2 – 6 ), muurolene‐type ( 7 ), alloaromadendrane‐type ( 8 ), and cyclocopacamphane‐type ( 9 ) skeletons, were isolated from the 60% EtOH extract of the stems of Dendrobium nobile. Their structures were established as (1R,2R,4S,5S,6S,8S,9R)‐2,8‐dihydroxycopacamphan‐15‐one ( 1 ), (2β,3β,4β,5β)‐2,4,11‐trihydroxypicrotoxano‐3(15)‐lactone ( 2 ), (2β,3β,5β,9α,11β)‐2,11‐epoxy‐9,11,13‐trihydroxypicrotoxano‐3(15)‐lactone ( 3 ), (2β,3β,5β,12R*)‐2,11,13‐trihydroxypicrotoxano‐3(15)‐lactone ( 4 ), (2β,3β,5β,12S*)‐2,11,13‐trihydroxypicrotoxano‐3(15)‐lactone ( 5 ), (2β,3β,5β,9α)‐9,10‐cyclo‐2,11,13‐trihydroxypicrotoxano‐3(15)‐lactone ( 6 ), (9β,10α)‐muurol‐4‐ene‐9,10,11‐triol ( 7 ), (10α)‐alloaromadendrane‐10,12,14‐triol ( 8 ), and (5β)‐cyclocopacamphane‐5,12,15‐triol ( 9 ) on the basis of spectroscopic analysis. The absolute configuration of compound 1 was tentatively assigned as (1R,2R,4S,5S,6S,8S,9R) according to its CD spectrum and the octant rule. Compounds 1 and 4 – 9 were inactive in our preliminary in vitro immunomodulatory bioassay.  相似文献   

7.
《Tetrahedron: Asymmetry》2005,16(23):3913-3918
The synthesis of abutasterone-type side chain, (20R,22R,24S)-20,22,24,25-tetrahydroxy-6β-methoxy-3α,5-cyclo-5α-cholestane 4, and 24-epi-abutasterone-type side chain, (20R,22R,24R)-20,22,24,25-tetrahydroxy-6β-methoxy-3α,5-cyclo-5α-cholestane 6, by means of Sharpless asymmetric dihydroxylation of (E)-20(22),24-cholestadiene 1 is described. Construction of abutasterone-type side chain 4 was carried out by selective mono-dihydroxylation of diene 1 with (DHQ)2AQN, followed by dihydroxylation of the corresponding (24S)-hydroxy-20(22)-cholestene 2 with (DHQD)2AQN. In contrast, bis-dihydroxylation of 1 with either (DHQD)2PHAL or (DHQD)2AQN preferentially occurs to produce 24-epi-abutasterone-type side chain 6.  相似文献   

8.
Synthesis of Optically Active Carotenoids with (R)-4-Hydroxy β-End Groups We describe the synthesis of optically active iso-β-kryptoxanthin ( 12 ; (R)-β,β-caroten-4-ol), iso-α-kryptoxanthins 14 ((4R,6′RS)-β,ε-caroten-4-ol) and 16 ((4R,6′R)-β,ε-caroten-4-ol), 4′-hydroxyechinenone ( 18 ; (R)-4′-hydroxy-β,β-caroten-4-one), and isorubixanthin ( 20 ; (R)-β,ω,-caroten-4-ol), their 400-MHz-1H-NMR spectra, CD spectra and HPLC behaviour.  相似文献   

9.
Five new steroidal glycosides were isolated from the roots of Balanites aegyptiaca, a widely used African medicinal plant. On the basis of spectroscopic and chemical evidence, their structures were determined as (3β,12α,14β,16β)‐12‐hydroxycholest‐5‐ene‐3,16‐diyl bis(β‐D ‐glucopyranoside) ( 1 ), (3β,20S,22R,25R)‐ and (3β,20S,22R,25S)‐26‐(β‐D ‐glucopyranosyloxy)‐22‐methoxyfurost‐5‐en‐3‐yl β‐D ‐xylopyranosyl‐(1→3)‐β‐D ‐glucopyranosyl‐(1→4)[α‐L ‐rhamnopyranosyl‐(1→2)]‐β‐D ‐glucopyranoside ( 2 and 3 , resp.), and (3β,20S,22R,25R)‐ and (3β,20S,22R,25S)‐spirost‐5‐en‐3‐yl β‐D ‐xylopyranosyl‐(1→3)‐β‐D ‐glucopyranosyl‐(1→4)[α‐L ‐rhamnopyranosyl‐(1→2)]‐β‐D ‐glucopyranoside ( 4 and 5 , resp.)  相似文献   

10.
Competition of Endoperoxide and Hydroperoxide Formation in the Reaction of Singlet Oxygen with Cyclic, Conjugated Dienes Rose-bengal-sensitized photooxygenation of (?)-(R)-α-phellandrene ( 1 ) in MeOH at room temperature yielded a complex mixture of products, contrary to previous reports describing cis-(3S, 6R)-epidioxy-p-menthene ( 2 ) and trans-(3R, 6S)-epidioxy-p-menthene ( 3 ) as the only products. The mixture was separated by prep. HPLC (silica gel, pentane/Et2O 9:1). Besides the known endoperoxides 2 (yield 39%) and 3 (26%), all those hydroper-oxides, which can be deduced from an ene reaction of 1O2 with 1 , were isolated, i.e. 4β-p-mentha-2,5-dien-1β-yl hydroperoxide ( 4 ) (14%), 4β-p-mentha-2,5-dien-1α-yl hydroperoxide ( 5 ) (9%), (2R, 4R)-p-mentha-1(7), 5-dien-2-yl hydroperoxide ( 6 ) (2,1%), (2S, 4R)-p-mentha-1(7),5-dien-2-yl hydroperoxide ( 7 ) (1,5%) and (1R)-p-mentha-3,6-dien-yl hydroperoxide ( 8 ; 1,5%; Scheme 1). Furthermore, the constant cis/trans ratio for all diastereoisomeric pairs ( 2 / 2 , 4 / 2 , 6 / 2 ) was striking. With the help of the two possible conformers 1a and 1b of the starting material a model of a common first step for endoperoxide as well as for hydroperoxide formation is developed. A photooxygenation at ?50° supports this model. The absolute value of the cis/trans ratio changes in the same way for the endoperoxides and the hydroperoxides.  相似文献   

11.
Synthesis and Chirality of (5R, 6R)-5,6-Dihydro-β, ψ-carotene-5,6-diol, (5R, 6R, 6′R)-5,6-Dihydro-β, ε-carotene-5,6-diol, (5S, 6R)-5,6-Epoxy-5,6-dihydro-β,ψ-carotene and (5S, 6R, 6′R)-5,6-Epoxy-5,6-dihydro-β,ε-carotene Wittig-condensation of optically active azafrinal ( 1 ) with the phosphoranes 3 and 6 derived from all-(E)-ψ-ionol ( 2 ) and (+)-(R)-α-ionol ( 5 ) leads to the crystalline and optically active carotenoid diols 4 and 7 , respectively. The latter behave much more like carotene hydrocarbons despite the presence of two hydroxylfunctions. Conversion to the optically active epoxides 8 and 9 , respectively, is smoothly achieved by reaction with the sulfurane reagent of Martin [3]. These syntheses establish the absolute configurations of the title compounds since that of azafrin is known [2].  相似文献   

12.
Four new furostanol steroid saponins, borivilianosides A–D ( 1 – 4 , resp.), corresponding to (3β,5α,22R,25R)‐26‐(β‐D ‐glucopyranosyloxy)‐22‐hydroxyfurostan‐3‐yl Oβ‐D ‐xylopyranosyl‐(1→3)‐Oβ‐D ‐glucopyranosyl‐(1→4)‐O‐[α‐L ‐rhamnopyranosyl‐(1→2)]‐β‐D ‐galactopyranoside ( 1 ), (3β,5α,22R,25R)‐ 26‐(β‐D ‐glucopyranosyloxy)‐22‐methoxyfurostan‐3‐yl Oβ‐D ‐xylopyranosyl‐(1→3)‐Oβ‐D ‐glucopyranosyl‐(1→4)‐O‐[α‐L ‐rhamnopyranosyl‐(1→2)]‐β‐D ‐galactopyranoside ( 2 ), (3β,5α,22R,25R)‐26‐(β‐D ‐glucopyranosyloxy)‐22‐methoxyfurostan‐3‐yl Oβ‐D ‐xylopyranosyl‐(1→3)‐O‐[β‐D ‐glucopyranosyl‐(1→2)]‐Oβ‐D ‐glucopyranosyl‐(1→4)‐β‐D ‐galactopyranoside ( 3 ), and (3β,5α,25R)‐26‐(β‐D ‐glucopyranosyloxy)furost‐20(22)‐en‐3‐yl Oβ‐D ‐xylopyranosyl‐(1→3)‐O‐[β‐D ‐glucopyranosyl‐(1→2)]‐Oβ‐D ‐glucopyranosyl‐(1→4)‐β‐D ‐galactopyranoside ( 4 ), together with the known tribuluside A and (3β,5α,22R,25R)‐26‐(β‐D ‐glucopyranosyloxy)‐22‐methoxyfurostan‐3‐yl Oβ‐D ‐xylopyranosyl‐(1→2)‐O‐[β‐D ‐xylopyranosyl‐(1→3)]‐Oβ‐D ‐glucopyranosyl‐(1→4)‐O‐[α‐L ‐rhamnopyranosyl‐(1→2)]‐β‐D ‐galactopyranoside were isolated from the dried roots of Chlorophytum borivilianum Sant and Fern . Their structures were elucidated by 2D ‐NMR analyses (COSY, TOCSY, NOESY, HSQC, and HMBC) and mass spectrometry.  相似文献   

13.
Upon heating in AcOH, the stereoisomeric (Z)- and (R)-6,9-dioxocyclodex-3-enyl derivatives, 5 and 6 , respectively, obtained by HgO/I2 oxidation of 5-hydroxy-8-oxo-8,14-seco-5α-androstane-3β,17β-diyl diacetate ( 3 ), undergo an unusual intramolecular rearrangement to give the corresponding unsaturated (5R,9R)- and (5R,9S)-spiro-lactones 7 and 8 , respectively. Hydroxylation of the C?C bond in 7 and 8 , and subsequent glycol cleavage of the resulting diols 9 and 10 afforded the epimeric spiro-lactones (5R,9S)- 11 and (5R,9R)- 14 , respectively, and in both cases, the ring-D-containing fragments 12 and 13 .  相似文献   

14.
Stereochemical Correlations between (2R,4′R,8′R)-α-Tocopherol, (25S,26)-Dihydroxycholecalciferol, (–)-(1S,5R)-Frontalin and (–)-(R)-Linalol The optically active C5- and C4-building units 1 and 2 with their hydroxy group at a asymmetric C-atom were transformed to (–)-(1S,5R)-Frontalin ( 7 ) and (–)-(3R)-Linalol ( 8 ) respectively; 1 and 2 had been used earlier in the preparation of the chroman part of (2R,4′R,8′R)-α-Tocopherol ( 6a , vitamin E), and for introduction of the side chain in (25S,26)-Dihydroxycholecalciferol ((25S)- 4 ), a natural metabolite of Vitamin D3. The stereochemical correlations resulting from these converions fit into a coherent picture with those correlations already known from literature and they confirm our earlier stereochemical assignments. A stereochemical assignment concerning the C(25)-epimers of 25,26-Dihydroxycholecalciferol that was in contrast to our findings and that initiated the conversion of 1 and 2 to 7 resp. 8 for additional stereochemical correlations has been corrected in the meantime by the authors [26].  相似文献   

15.
Two novel sesquiterpene polyol esters with a dihydro‐β‐agarofuran (=(3R,5aS,9R,9aS)‐octahydro‐2,2,5a,9‐tetramethyl‐2H‐3,9a‐methano‐1‐benzoxepin) skeleton, (1α,2α,4β,8α,9α)‐1,2,8,12‐tetrakis(acetyloxy)‐9‐(furoyloxy)‐4‐hydroxydihydro‐β‐agarofuran ( 1 ) and (1α,2α,6β,8α,9α)‐1,2,6,8,12‐pentakis(acetyloxy)‐9‐(benzoyloxy)dihydro‐β‐agarofuran ( 2 ), and the three known compounds (1α,2α,4β,6β,8α,9β)‐1,2,6‐tris(acetyloxy)‐9‐(benzoyloxy)‐4‐hydroxy‐8,12‐bis(isobutyryloxy)dihydro‐β‐agarofuran ( 3 ), (1α, 2α,4β,6β,8α,9β)‐1,2,6,8‐tetrakis(acetyloxy)‐9‐(furoyloxy)‐4‐hydroxy‐12‐isobutyryloxy)dihydro‐β‐agarofuran ( 4 ), and (1α,2α,4β,6β,8α,9β)‐1,2,6‐tris(acetyloxy)‐9‐(benzoyloxy)‐4‐hydroxy‐8‐(isobutyryloxy)‐12‐[(2‐methylbutanoyl)oxy]dihydro‐β‐agarofuran ( 5 ) were isolated from the root bark of Celastrus angulatus. Their chemical structures were elucidated by analyses of their MS and NMR data.  相似文献   

16.
The new withanolides ajugin C (=(20R,22R)-4β,14α,20,27-tetrahydroxy-1-oxoergosta-2,5,24-trieno-26,22-lactone; 1 ) and ajugin D (=(20R,22R)-8β,14α,17β,20,27-pentahydroxy-1-oxoergosta-5,24-dieno-26,22-lactone; 2 ) were isolated from the whole plant of Ajuga parviflora. Their structures were determined by spectroscopy, including 2D-NMR.  相似文献   

17.
Two new epimeric chlorinated withaphysalins, rel‐(4β,5β,6α,18S,22R)‐ and rel‐(4β,5β,6α,18R,22R)‐6‐chloro‐18,20‐epoxy‐18‐ethoxy‐4,5‐dihydroxy‐1‐oxowitha‐2,24‐diene‐26,22‐lactone ( 1 and 2 resp.), together with the new rel‐(4β,5β,6α,18R,22R)‐6‐chloro‐18,20‐epoxy‐4,5‐dihydroxy‐18‐methoxy‐1‐oxowitha‐2,24‐diene‐26,22‐lactone ( 3 ) and rel‐(3β,4β,5β,6β,18R,22R)‐5,6:18,20‐diepoxy‐3,18‐diethoxy‐4‐hydroxy‐1‐oxowith‐24‐ene‐26,22‐lactone ( 4 ) were isolated from the leaves of Acnistus arborescens and named withaphysalins T–W, respectively. The final structures and the complete 1H‐ and 13C‐NMR assignments of the three chlorowithaphysalins 1 – 3 were performed by means of HR‐ESI‐MS and 1D‐ and 2D‐NMR experiments, including COSY, HSQC, and HMBC, beside comparison with spectral data of analogous compounds from the literature. The structure of 4 was also confirmed by means of a single‐crystal X‐ray diffraction analysis.  相似文献   

18.
Three new monoterpenoid indole alkaloids, vinmajorines C–E ( 1 – 3 ), along with 18 known analogues ( 4 – 21 ), were isolated from the whole plants of Vinca major. The new structures were elucidated as (5α,15β,16R,17α,19β,20α,21β)‐10,17‐dimethoxy‐21‐methyl‐18‐oxa‐5,16‐cycloyohimban‐19‐ol ( 1 ), (5α,15β,16R,17α,20α,21β)‐10‐methoxy‐21‐methyl‐18‐oxa‐5,16‐cycloyohimban‐17‐ol ( 2 ), and (5α,15β,16R,17α,20α,21β)‐10‐methoxy‐21‐methyl‐18‐oxa‐5,16‐cycloyohimban‐17‐yl acetate ( 3 ), respectively, by extensive NMR and MS analysis and comparison with known compounds. Compounds 1 – 3 were evaluated for their cytotoxic activities against five human cancer cell lines, compounds 1 and 3 showing moderate cytotoxic activities.  相似文献   

19.
Three new and one known ecdysteroids were identified in the MeOH extract of the roots of Serratula wolffii. The new compounds isolated were (11α)‐11‐hydroxyshidasterone ( 1 ), (2β,3α,5β,14β,22R)‐2,3,20,22,25‐pentahydroxycholest‐7‐en‐6‐one ( 2 ), and (2β,3α,5β,22R)‐2,3,20,22,25‐pentahydroxycholest‐7‐en‐6‐one ( 3 ), together with the known ponasterone A ( 4 ). This latter compound was now better characterized than earlier. The structures of compounds 1 – 4 were established by extensive spectroscopic techniques, including one‐ and two‐dimensional NMR methods.  相似文献   

20.
A new furostanol saponin, sisalasaponin C ( 1 ), and a new spirostanol saponin, sisalasaponin D ( 2 ), were isolated from the fresh leaves of Agave sisalana, along with three other known steroidal saponins and two stilbenes. Their structures were identified as (3β,5α,6α,22α,25R)‐3,26‐bis[(β‐D ‐glucopyrano‐ syl)oxy]‐22‐hydroxyfurostan‐6‐yl β‐D ‐glucopyranoside ( 1 ), (3β,5α,25R)‐12‐oxospirostan‐3‐yl 6‐deoxy‐α‐L ‐mannopyranosyl‐(1→4)‐β‐D ‐glucopyranosyl‐(1→3)‐[β‐D ‐xylopyranosyl‐(1→3)‐β‐D ‐glucopyranosyl‐(1→2)]‐β‐D ‐glucopyranosyl‐(1→4)‐β‐D ‐galactopyranoside ( 2 ), (3β,5α,6α,22α,25R)‐22‐methoxyfurostane‐3,6,26‐triyl tris‐β‐D ‐glucopyranoside, cantalasaponin‐1, polianthoside D, (E)‐ and (Z)‐2,3,4′,5‐tetrahydroxystilbene 2‐O‐β‐D ‐glucopyranosides. The last three known compounds were isolated from the fresh leaves of Agavaceae for the first time. The structures of the new compounds were elucidated by detailed spectroscopic analysis, including 1D‐ and 2D‐NMR experiments, and chemical techniques.  相似文献   

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