Syntheses of 6,8-disubstituted-9-β-D-ribofuranosylpurine 3′,5′-cyclic phosphates

A series of 6,8-disubstituted-9-β-D-ribofuranosylpurine 3′,5′-cyclic phosphates were prepared employing preformed 9-β-D-ribofuranosylpurine 3′,5′-cyclic phosphate precursors. Three synthetic approaches were utilized to accomplish the syntheses. The first approach involved a study of the order of nucleophilic substitution, 6 vs 8, of the intermediate 6,8-dichloro-9-β-D-ribofuranosyipurine 3′,5′-cyclic phosphates ( 2 ) with various nucleophilic agents to yield 8-amino-6-chloro-, 8-chloro-6-(diethylamino)-, 6-chloro-8-(diethylamino)-, 6,8-bis-(diethylamino)- and 8-(benzylthio)-6-chloro-9-β-D-ribofuranosylpurine 3′,5′-cyclic phosphate (4, 9, 10, 11, 13) respectively and 6-chloro-9-β-D-ribofuranosylpurin-8-one 3′,5′-cyclic phosphate ( 5 ) and 8-amino-9-β-D-ribofuranosylpurine-6-thione 3′,5′-cyclic phosphate ( 6 ). The order of substitution was compared to similar substitutions on 6,8-dichloropurines and 6,8-dichloropurine nucleosides. The second scheme utilized nucleophilic substitution of 6-chloro-8-substituted-9-β-D-ribofuranosylpurine 3′,5′-cyclic, phosphates obtained from the corresponding 8-subslituted inosine 3′,5′-cyclic phosphates by phosphoryl chloride, 6,8-bis-(benzylthio)-, 6-(diethylamino)-8-(benzylthio),8-(p-chlorophenylthio(-6-(diethylamino)- and 6,8-bis-(methyl-thio)-9-β-D-ribofuranosylpurine 3′,5′-cyclic phosphates ( 14, 12, 20 , and 21 ) respectively, were prepared in this manner. The final scheme involved N¹-alkylation of an 8-substituted adenosine 3′,5′-cyclic phosphate followed by a Dimroth rearrangement to give 6-(benzylamino)-8-(methylthio)- and 6-(benzylamino)-8-bromo-9-β-D-ribofuranosylpurine 3′,5′-cyclic phosphate ( 24 and 25 ).     

由2'''',4''''-二氢-6''''-甲氧基-3'''',5''''-二甲基查耳酮合成新黄酮

在DMSO/ I2的氧化作用下,由2',4'-二氢-6'-甲氧基-3',5'-二甲基查耳酮可合成一种全新结构的黄酮:7-羟基-5-甲氧基-6,8-二甲基黄酮(产率91%),而在HCl/MeOH作用下则得到了两种黄烷酮:7-羟基-5-甲氧基-6,8-二甲基黄烷酮 (产率70%) 和 5,7-二羟基-6,8-二甲基黄烷酮 (产率20%).     

Two new triterpenoids from Gypsophila oldhamiana

Two new triterpenoids (1–2) were isolated and elucidated from the roots of Gypsophila oldhamiana, together with four known triterpenoids (3–6). Their structures were identified to be 3β-hydroxyolean-13(18)-ene-23, 28-dioic acid (1), 3β, 12α-dihydroxy-23-carboxyolean-28, 13β-olide (2), 3β, 16α-dihydroxy-23-oxoolean-13(18)-en-28-oic acid (3), gypsogenin (4), quillaic acid (5) and gypsogenic acid (6) by spectral methods. All compounds were tested for their cytotoxicities against human tumour cell lines (lung cancer H460 and gastric cancer SGC-7901) and for their antiangiogenic effects using a zebra fish model. All compounds showed interesting antiangiogenic activities and the significant cytotoxicities against H460.     

Reactions of Substituted 2,3,7-Triazabicyclo[3.3.0]oct-2-enes and 1,2,7-Triazaspiro[4.4]non-1-enes with Halogens

Halogenation of 1-substituted 7-aryl-2,3,7-triazabicyclo[3.3.0]oct-2-ene-6,8-diones gives different products, depending on the substituent in position 1 (R¹): when R¹ = Ar, 6-chloro-3-azabicyclo[3.1.0]hexanes are formed, while compounds with R¹ = H or Me give rise to 2- or 4-chloro-2,3,7-triazabicyclo[3.3.0]oct-2-ene-6,8-diones whose thermolysis leads to formation of the corresponding 6-chloro-3-azabicyclo[3.1.0]hexanes. Chlorination of 7-aryl-1,2,7-triazaspiro[4.4]non-1-ene-6,8-diones yields 3-chloro-1,2,7-triazaspiro[4.4]non-1-ene-6,8-diones, and thermolysis of the latter affords 1-chloro-5-azaspiro[2.4]heptanes.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 1, 2005, pp. 78–88.Original Russian Text Copyright © 2005 by Molchanov, Stepakov, Kostikov.     

新型碳苷糖类维生素D_2衍生物的合成

以D-葡萄糖为原料,经碳苷化反应,酰化反应和脯氨酸-DIPEA催化的aldol反应制得2个碳苷糖[1-(4'-羟基苯基)-4-C-β-四乙酰基葡萄糖基-3-烯-2-酮(5a)和1-(3-羟基苯基)-4-C-β-四乙酰基葡萄糖基-3-烯-2-酮(5b)];5与琥珀酸维生素D2经Steglich酯化反应合成了2个新型碳苷糖类维生素D2衍生物,其结构经1H NMR,13C NMR和HR-ESI-MS表征。     

A new ent-clerodane diterpenoid from Crassocephalum bauchiense Huch. (Asteraceae)

A phytochemical investigation of the whole plant of Crassocephalum bauchiense Huch. resulted in the isolation of a new clerodane diterpenoid, ent-2β,18,19-trihydroxycleroda-3,13-dien-16,15-olide (1), together with two known flavonoids 3′,5-dihydroxy-4′,5′,6,7,8-pentamethoxyflavone (2) and 4′,5-dihydroxy-3′,5′,6,7,8-pentamethoxyflavone (3). The compounds were tested against the chloroquine-sensitive 3D7 strain of Plasmodium falciparum. Compound 2 showed weak activity (IC₅₀ = 10.1 g/mL) whilst compounds 1 and 3 were inactive. The structures of the compounds were elucidated by using detailed spectral analyses, especially ¹H and ¹³C NMR, ¹H–¹H COSY, NOESY, HMBC and HR-ESI-MS.     

Flavone glucosides from Artemisia juncea

A new flavone glucoside, 4′,5-dihydroxy-3′,5′,6-trimethoxyflavone-7-O-β-D-glucoside was obtained from aerial parts of Artemisia juncea, together with the known flavone eupatilin (5,7-dihydroxy-3′,4′,6-trimethoxyflavone). The compounds were comprehensively analytically characterized by IR, UV, NMR and HR-MS, and their chemical structures ascertained. The EtOAc fraction of A. juncea showed the strongest DPPH radical scavenging ability as well as reducing power (in CUPRAC and FRAP assays) and phosphomolybdenum activity. This fraction also exhibited the strongest inhibitory effects on tyrosinase. Additionally, the best antidiabetic effects were observed for eupatilin and the CHCl₃ fraction.     

Synthese von optisch aktiven,natürlichen Carotinoiden und strukturell verwandten Naturprodukten. VIII. Synthese von (3S,3′S)-7,8,7′,8′-Tetradehydroastaxanthin und (3S,3′S)-7,8-Didehydroastaxanthin (Asterinsäure)

Synthesis of Optically Active Natural Carotenoids and Structurally Related Compounds. VIII. Synthesis of (3S,3′S)-7,8,7′,8′-Tetradehydroastaxanthin and (3S,3′S)-7,8-Didehydroastaxanthin (Asterinic Acid) The synthesis of all-trans-(3S,3′S)-3,3′-dihydroxy-7,8, 7′,8′-tetradehydro-β, β-carotene-4,4′-dione ( 1 ), of all-trans-(3S,3′S)-3,3′-dihydroxy-7, 8-didehydro-β,β-carotene-4,4′-dione ( 2 ) (asterinic acid = mixture of 1 and 2 ), and of their 9,9′-di-cis- and 9-cis-isomers is reported starting from (4′S)(2E)-5-(4′-hydroxy-2′, 6′,6′-trimethyl-3′-oxo-l′-cyclohexenyl)-3-methyl-2-penten-4-ynal ( 8 ). The absolute configuration (3S,3′S) for both components 1 and 2 of asterinic acid ex Asterias rubens is confirmed on the basis of spectroscopic and direct comparison.     

Synthesis,Characterization, and Antimicrobial Evaluation of the Novel Triazolotriazolopyridines and Pyridotriazolotriazines

The starting compound 2‐hydrazinyl‐7‐(4‐methoxyphenyl)‐5‐oxo‐3,5‐dihydro[1,2,4]triazolo[1,5‐a ]pyridine‐6,8‐dicarbonitrile ( 5 ) was efficiently synthesized from 1,6‐diamino‐4‐(4‐methoxyphenyl)‐2‐oxo‐1,2‐dihydropyridine‐3,5‐dicarbonitrile ( 1 ). A novel series of polynuclear [1,2,4]triazolo[4′,3′:2,3][1,2,4]triazolo[1,5‐a ]pyridines 6 , 7 , 8 , 9 , 10 and pyrido[1′,2′:2,3][1,2,4]triazolo[5,1‐c ][1,2,4]triazines 11 , 12 , 13 , 14 , 15 have been synthesized. Structures of the newly synthesized products have been deduced on the basis of elemental analysis and spectral data. The synthesized compounds were screened for their antimicrobial activity.     

The Terpenoids of Maytenus boaria MOL. (Celastraceae)

The known triterpenoids β-amyrin (= olean-12-en-3β-ol; 22 ), lupeol (= lup-20(29)-en-3β-ol; 17 ), betulin (= lup-20(29)-ene-3β,28-diol; 18 ), lup-20(29)-ene-3β,30-diol ( 20 ), oleanolic acid (= 3β-hydroxyolean-12-en-28-oic acid; 21 ), and betulonic acid (= 3-oxolup-20(29)-en-28-oic acid; 19 ), together with epicatechol (= cis-2-(3,4-dihydroxyphenyl)-3,4-dihydro-2H-1-benzopyran-3,5,7-triol; 23 ), 5′-O-methylgallocatechol (= trans-2-(3,4-dihydroxy-5-methoxyphenyl)-3,4-dihydro-2H-1-benzopyran-3,5,7-triol; 24 ), and 4-hydroxybenzaldehyde were isolated from the aerial parts of Maytenus boaria (MOL. ). Additonally, the eight 4,C⁴-dihydro-β-agarofuran sesquiterpenoids 1–8 , one of them a diol with a (4R)-configuration, and compound 9 were present in the extract. The structures of these compounds were established by spectroscopic and chemical means.     

Unusual Guaiane Sesquiterpenoids from Artemisia rupestris

Two new guaiane sesquiterpenoids, (1β,5β)‐1‐hydroxyguaia‐4(15),11(13)‐dieno‐12,5‐lactone ( 1 ) and 1,5‐epoxy‐4‐hydroxyguai‐11(13)‐en‐12‐oic acid ( 2 ), together with five known compounds, rupestonic acid ( 3 ), strobilactone A ( 4 ), antiquorin ( 5 ), isosclerone ( 6 ), and 5‐hydroxy‐2′,3′,4′,7,8‐pentamethoxyflavone ( 7 ), were isolated from a 95% EtOH extract of Artemisia rupestris. Compounds 1 and 2 are rare examples of guaiane sesquiterpenoids, incorporating a 12,5‐lactone group or featuring a 1,5‐epoxy ring, respectively. The structures of 1 and 2 were identified by various spectroscopic methods. Compounds 1, 4 , and 5 exhibited moderate cytotoxic activities against the human lung cancer 95‐D cell line with IC₅₀ values of 11.3, 19.8, and 34.5 μM , respectively.     

Spectral characteristics of C-methylflavones

A study has been made of natural C-methylflavones and their dealkylated analogues: 5-hydroxy-4,7-dimethoxy-7-methylflavone (noreucalyptin); 4,5,7-trihydroxy-6-methylflavone; 5-hydroxy-4,7-dimethoxy-6,8-dimethylflavone (eucalyptin); 4,5-dihydroxy-7-methoxy-6,8-dimethylflavone (sideroxylin); 4,5,7-trihydroxy-6,8-dimethylflavone; 4,5,6-trihydroxy-3-methoxy-8-methylflavone (silpin) and 3,4,5,6-tetrahydroxy-8-methylflavone.All-Union Scientific-Research Institute of Medicinal Plants, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 306–309, May–June, 1984.     

Identification de xanthones et de nouveaux arabinosides de C-glucosides flavoniques dans Swertia perennisL.

Identification of xanthones and new arabinosides of flavone C-glucosides from Swertia perennis L. – Seven tetraoxygenated xanthones [1,3,7,8-tetrahydroxy-xanthone ( 1 ); 1,8-dihydroxy-3,7-dimethoxy-xanthone ( 2 ); 1,7-dihydroxy-3,8-dimethoxy-xanthone ( 3 ); 1-hydroxy-3,7,8-trimethoxy-xanthone ( 4 ); 3,7,8-trihydroxy-xanthone-xanthone-1-0-β-glucoside ( 5 ); 3,7,8-trimethoxy-xanthone-1-0-primeveroside ( 6 ); 8-hydroxy-3,7-dimethoxy-xanthone-1-0-primeveroside ( 7 )] have been isolated chromatographically, using polyamide columns, from roots of Swertia perennis L . From leaves and stems of the same plant, six xanthones [1,5,8-trihydroxy-3-methoxy-xanthone ( 8 ); 1,5-dihydroxy-3-methoxy-xanthone-8-0-β-glucoside ( 9 ); mangiferin ( 10 ); 1 ; 4 ; 5 ] and four flavone C-glycosides [iso-orientin ( 11 ); isovitexin ( 12 ); iso-orientin-6″-arabinoside ( 13 ); isovitexin-6″-arabinoside ( 14 )] have also been isolated. Among these compounds, 7 , 13 and 14 were not encountered before in nature. In the last two compounds, the position of arabinose on the C-glucoside moiety of the flavone was established by ¹³C-NMR. spectroscopy.     

Reaction of Substituted 6,8-Dioxo-2,3,7-triazabicyclo[3.3.0]oct-3-ene-4-carboxylates and 6,8-Dioxo-1,2,7-triazaspiro[4.4]non-2-ene-3-carboxylates with N-Fluoropyridinium Tetrafluoroborate

Substituted 6,8-dioxo-2,3,7-triazabicyclo[3.3.0]oct-3-ene-4-carboxylates react with N-fluoropyridinium tetrafluoroborate to give mixtures of exo and endo isomers of 6-fluoro-2,4-dioxo-3-azabicyclo[3.1.0]hexane-6-carboxylates. Analogous reaction of 6,8-dioxo-1,2,7-triazaspiro[4.4]non-2-ene-3-carboxylates results in formation of syn,anti-isomeric 1-fluoro-4,6-dioxo-5-azaspiro[2.4]heptane-1-carboxylates.     

On the formation of homo-azasteroidal esters of N,N-bis(2-chloroethyl)aminobenzoic acid isomers and their antitumor activity

The N, N-bis(2-chloroethyl)aminobenzoate isomers and the 4-methyl-3-N, N-bis(2-chloro-ethyl)aminobenzoate of 3β-hydroxy-13α-amino-13,17-seco-5α-androstan-17-oic-13,17-lactam, 3α-hydroxy-13α-amino-13,17-seco-5α-androstan-17-oic-13,17-lactam, 3α-hydroxy-13α-amino-13,17-seco-5-androsten-17-oic-13,17-lactam and 17β-hydroxy-3-aza-A-homo-4α-androsten-4-one, have been prepared and their biological activity evaluated against P388 leukemia in vivo and Ehrlich Ascites tumor (EAT), P388 and L1210 leukemias and Baby Hamster cells (BHK) in vitro. The esters in which the alkylating congener is linked to the lactam alcohol in the axial position are inactive in vivo in P388 leukemia, while compounds 1, 4, 6, 13, 14 and the alkylating congeners 17, 18 and 20 are active. The effect of the homo-azasteroidal of N, N-bis(2-chloroethyl)aminobenzoic acid isomers and of 4-methyl-3-N, N-bis(2-chloroethyl)aminobenzoic acid on the incorporation of the radioactive precursor into the DNA of L1210, P388 leukemias, Ehrlich ascites tumor and, baby Hamster kidney cells was investigated. Higher inhibitory effects on the incorporation of the radioactive precursor was obtained with the ortho derivatives, yielding <70% inhibition of thymidine incorporation in all tumor lines tested.     

Ilwensisaponins A,B, C,and D: Triterpene Saponins from Scrophularia ilwensis

From the aerial parts of Scrophularia ilwensis, four new triterpene saponins, ilwensisaponins A–D ( 1 – 4 ) were isolated. The structures of the compounds were elucidated using chemical and spectral data as 13β, 28-epoxy-3-β-{{[β-D -glucopyranosyl-(1→2)]-[α-L -rhamnopyranosyl-(1→4)-β-D -glucopyranosyl-(1→3)]-β-D -fucopyranosyl}-oxy} olean-11-en-23-ol ( 1 ), 3-β-{{[β-D -glucopyranosyl-(1→2)]-[α-L -rhamnopyranosyl-(1→4)-β-D -glucopyranosyl-(1→3)]-β-D -fucopyranosyl}oxy}olena-11, 13(18)-diene-23, 28-diol ( 2 ), 3-β-{{[β-D -glucopyranosyl-(1→2)]-[α-L -rhamnopyranosyl-(1→4)-β-D glucopyranosyl-(1→3)]-β-D fucopyranosyl}oxy}-11α-methoxyolean- 12-ene-23, 28-diol (3) , and 3-β-{{[β-D -glucopyransoyl-(1→2)]-[α-L -rhamnopyranosyl-(1→4)-β-D -glucopyranosyl-(1→3)]-β-D -fucopyranosyl}oxy}olean-12-ene-11α,23,28-triol (4) .     

Preparative separation of six coumarins from the pummelo (Citrus maxima (Burm.) Merr. Cv. Shatian Yu) peel by high-speed countercurrent chromatography

In this work, six coumarins, including two new ones, 8-(3-hydroxy-2,2-dimethylpropyl)-7-methoxy-2H-chromen-2-one (2) and 5-[(7′,8′-dihydroxy-3′,8′-dimethyl-2-nonadienyl)oxy] psoralen (4), as well as four known ones, 5-[(6′,7′-dihydroxy-3′,7′-dimethyl-2-octenyl) oxy] psoralen (1), marmin (3), epoxybergamottin (5), and aurapten (6) were successfully separated from the crude extract of pummelo (Citrus maxima (Burm.) Merr. Cv. Shatian Yu) peel by high-speed countercurrent chromatography in a single run with petroleum-ether–ethyl acetate–methanol–water (4:6:6:4, v/v). The structures of these six coumarins were elucidated by ESI-MS, extensive 1D and 2D NMR spectroscopy.     

Three new flavonoid glycosides from Smilax glabra and their anti-inflammatory activity

Three new flavonoid glycosides, 2(S)-5-hydroxy-6,8-dimethoxyflavonone-7-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranoside (1), 5-hydroxy-3,8-dimethoxyflavone-7-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranoside (2) and 3,7-dihydroxy-8-methoxyflavone-6-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranoside (3), together with five known flavonoids (4–8) were isolated from the roots of Smilax glabra Roxb. Their structures were elucidated on the basis of chemical and spectral evidence, as well as by comparison with literature data. Three new flavonoids were subjected to evaluate anti-inflammatory activity. Compounds 1–3 inhibited the NF κB induction by 32.2, 55.8 and 61.7%, respectively.