Anti-oxidative activity of glycosides from Ligustrum sinense

Three active glycosides that afford protection to red blood cell membrane to resist hemolysis induced by a peroxyl radical initiator, 2,2'-azo-bis-(2-amidinopropane) dihydrochloride (AAPH) were isolated from the MeOH extract of Ligustrum sinense. The compounds are 10-hydroxyl-oleuropein (1), 3-O-alpha-L-rhamnopyranosyl-kaempferol-7-O-beta-D-glucopyranoside (4), and 8'-alpha-hydroxyl-lariciresinol-4'-O-beta-D-glucopyranoside (6). The structures of these glycosides were determined by 1D and 2D NMR spectral analysis.     

Reactive oxygen species scavenging activity of flavone glycosides from Melilotus neapolitana

One new and six known flavone glycosides were isolated from the MeOH extract of Melilotus neapolitana Ten. The new compound, identified as 7-O-beta-D-glucopyranosyloxy-4',5-dihydroxy-3-[O-alpha-L-rhamnopyranosyl-(1-->6)-3-O-beta-D-glucopyranosyloxy]flavone (1) by 1D and 2D NMR techniques and mass spectra, was isolated along with kaempferol-3-O-rutinoside (2), kaempferol-3-O-glucoside (3), rutin (4), quercetin-3-O-glucoside (5), isorhamnetin-3-O-rutinoside (6), and isorhamnetin-3-O-glucoside (7). The antioxidant and radical scavenging activities of these compounds and the whole crude methanol extract were evaluated. The organic extract can inhibit MDA marker's synthesis by 57%. All the metabolites displayed good reducing power, with the kaempferol (2,3) and isorhamnetin derivatives (6,7) being less active than the corresponding quercetin derivatives 4,5.     

New constituents from the rhizomes of Egyptian Iris germanica L

Chemical investigation of the methanolic extract of the rhizomes of Iris germanica L. (Iridaceae) afforded two new compounds; irigenin S (7) and iriside A (12), together with ten known compounds: stigmasterol (1), a-irone (2), γ-irone (3), 3-hydroxy-5-methoxyacetophenone (4), irilone (5), irisolidone (6), irigenin (8), stigmasterol-3-O-β-D-glucopyranoside (9), irilone 4'-O-β-D-glucopyranoside (10) and iridin (11). Their structures were established by UV, IR, 1D (1H and 13C) and 2D (1H-1H COSY, HMQC, and HMBC) NMR spectroscopy, in addition to mass spectroscopic data and comparison with literature data. The methanolic extract was evaluated for its antimicrobial activity. Both the methanolic extract and the isolated flavonoids were tested for their anti-inflammatory activity.     

Cp2V] migration along an octatetrayne chain: from the monometallic complex (Cp2V(2-4eta-tBuC triple bond C2-C triple bond CC triple bond CtBu)] to the dimetallic complex

The oxidative addition of one equivalent of [Cp2V] (4) to the tetrayne ligand tBuC triple bond CC triple bond CC triple bond CC triple bond CtBu (5) gives the monometallic complex [Cp2V(3-4eta-tBuC triple bond C-C2-C triple bond CC triple bond CtBu)] (7). Compound 7 reacts further with a second equivalent of [Cp2V] to give the dimetallic complex [(Cp2V)2(1-2eta:7-8eta-tBuC2-C triple bond CC triple bond C-C2tBu)] (8), which involves a shift of the first coordinated [Cp2V] unit from the internal C3-C4 to the external C1-C2 positions on the alkynyl ligand. Compound 8 is also directly obtained by the addition of two equivalents of [Cp2V] to 5. Reversibly, reaction of 8 with 5 leads to 7. This exchange reaction between 7 and 8 by adding successively 5 and 4 has been monitored by EPR spectroscopy. By contrast, the oxidative addition of one or two equivalents of [Cp2V] to the tetrayne ligand PhC triple bond CC triple bond CC triple bond CC triple bond CPh (6) gives the homodimetallic complex [(Cp2V)2(1-2eta:7-8eta-PhC2-CC triple bond CC triple bond C-C2-Ph)] (9). Both monometallic and dimetallic complexes 7, 8, and 9 have been characterized by X-ray diffraction. Magnetic moment measurements for 8 and 9 from 300 to 4 K indicated a weak antiferromagnetic J exchange coupling of -12.5 and -4.1 cm(-1), respectively.     

Four New Triterpenes from Anchusa azurea var. azurea

Four new triterpene glycosides, named oleanazuroside 1 ( 1 ), oleanazuroside 2 ( 2 ), ursolazuroside 1 ( 3 ), and ursolazuroside 2 ( 4 ), together with the seven known compounds 5 – 11 , were isolated from the MeOH extract of the aerial parts of Anchusa azurea Miller var. azurea. Their structures were elucidated by means of spectroscopic evidence (UV, IR, MALDI‐MS, and 1D‐ and 2D‐NMR). The radical‐scavenging activities against 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) of the BuOH extract and of 8 and 10 were very strong (Table 5).     

Isolation and biological activity of new and known isolation and biological activity of new and known diterpenoids from Sideritis stricta Boiss. & Heldr

Nine known and one new ent-kaurene diterpenoid were isolated from the acetone extract of Sideritis stricta Boiss & Heldr. The new compound, identified as ent-1 beta-hydroxy-7 alpha-acetyl-15 beta,16 beta-epoxykaurane (1) by IR, 1D and 2D NMR techniques and mass spectra, was isolated along with sideroxol (2), 7-acetyl sideroxol (3), 7-epicandicandiol (4), linearol (5), ent-7 alpha,15 beta,18-trihydroxy-kaur-16-ene (6), ent-7 alpha-acetyl,15,18-dihydroxy-kaur-16-ene (7), foliol (8), sideridiol (9) and siderol (10). The antibacterial and antifungal activities of these compounds and the whole crude acetone extract were evaluated against E. coli, S. aureus, K. pneumeonia and C. albicans.     

Isocassiaoccidentalin B,A New C‐Glycosyl Flavone Containing a 3‐Keto Sugar,and Other Constituents from Cassia nomame

A new C‐glycosyl flavone containing a 3‐keto sugar, isocassiaoccidentalin B ( 1 ), was isolated from whole Cassia nomame (Sieber ) Honda plants, along with eleven known compounds, including two flavonoids ( 2 and 3 ), five flavonoid glycosides ( 4  –  8 ), two chalcones ( 9 and 10 ), and two phenylpropanoids ( 11 and 12 ). The chemical structures of all compounds were determined via 1D‐ and 2D‐NMR, and ESI‐MS. Among these, compounds 2 , 3 , 7 , and 8 were found to be the most potent in inhibiting nitric oxide release. Compounds 1 , 2 , 4 , 8 , 9 , and 10 showed significant free‐radical scavenging activity.     

Cytotoxic compounds from the leaves of Gaillardia aristata Pursh. growing in Egypt

Ten compounds, neopulchellin (1), 6α- hydroxyneopulchellin (2), β-sitosterol-3-O-β-D-glucoside (3), apigenin (4), quercitin (5), eupafolin (6), kaempferol-3-methoxy-7-O-α-L-rhamnoside (7), apigenin-7-O-β-D-glucopyranoside (8), α-amyrin (9) and β-sitosterol (10), were isolated from the leaves of Gaillardia aristata by applying bioassay guided fractionation. The cytotoxicity was traced against two human cancer cell lines (breast (MCF7) and colon (HCT116)). The highest cytotoxicity was revealed by compounds 1 and 2 (isolated from chloroform extract); with IC(50) values of 0.43, 0.32?μg?mL(-1) against MCF7 and 0.46, 0.34?μg?mL(-1) against HCT116, respectively. Compounds 9 and 10 (isolated from the n-hexane extract) exhibited lower IC(50) values of 3.05, 2.35?μg?mL(-1) against MCF7 and 3.05, 2.35?μg?mL(-1) against HCT116, respectively, while compounds 4-7 obtained from the ethyl acetate extract revealed the lowest cytotoxicity. Identification of the aforementioned compounds was carried out on the basis of their physico-chemical properties and spectral analysis (UV, EI/MS, 1D and 2D).     

Identification of major alkaloids and steroidal saponins in rat serum by HPLC-diode array detection-MS/MS following oral administration of Huangbai-Zhimu herb-pair Extract

Huangbai-Zhimu herb-pair (HBZMHP) is a widely used Chinese traditional medicine formula in treating various diseases; however, its active components have remained unknown. In this paper, serum chemistry and combined high-performance liquid chromatography (HPLC), diode-array detection and mass-spectrometry (MS) techniques were used to study the constituents of HBZMHP extract absorbed into rat serum after oral administration. A total of nine characteristic HPLC peaks in the TIC chromatograms were identified as magnoflorine (1), menisperine (2), palmatine (3), berberine (4), timosaponin N or timosaponin E1 (5), timosaponin D (6), timosaponin BIII, anemarsaponin C or xilingsaponin B (7) timosaponin BII (8) and timosaponin AIII (9). All of the identified peaks were constituents of HBZMHP extract. The results narrow the range of active compounds to be found in HBZMHP extract, and pave the way for the follow-up action mechanism research.     

Phenolic compounds from Eucalyptus gomphocephala with potential cytotoxic and antioxidant activities

Two new phenolic compounds, 2,4,6-trihydroxy-5-methyl-acetophenone 2-O-beta-D-glucopyranoside (3), and benzyl alcohol 7-O-(3',4',6'-tri-O-galloyl)-beta-D-glucopyranoside (8), together with eight known phenolic compounds, were isolated from the 70% aqueous acetone extract of Eucalyptus gomphocephala DC. (Myrtaceae). The isolated compounds were elucidated based on their 1H, 13C, DQF-COSY, selective 1D-TOCSY, HSQC, and HMBC NMR spectroscopic and ESI-MS data. The antioxidant effect of the phenolic compounds was tested using 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical and super oxide anion radical scavenging assays. The cytotoxicity of the isolated compounds was evaluated using HeLa cell line.     

Synthesis and charge/discharge properties of polyacetylenes carrying 2,2,6,6-tetramethyl-1-piperidinoxy radicals

The 2,2,6,6-tetramethyl-1-piperidinoxy (TEMPO)-containing acetylenic monomers HC[triple bond]CC(6)H(3)-p,m-(CONH-4-TEMPO)(2) (1), HC[triple bond]CC(6)H(3)-p,m-(COO-4-TEMPO)(2) (2), (S,S,S,S)-HC[triple bond]CC(6)H(3)-p,m-[CO-NHCH{COO-(4-TEMPO)}CH(2)COO-(4-TEMPO)](2) (3), (S,S)-HC[triple bond]CC(6)H(4)CO-NHCH{COO-(4-TEMPO)}CH(2)COO-(4-TEMPO) (4), HC[triple bond]CC(6)H(4)-p-OCO-4-TEMPO (5), HC[triple bond]CCH(2)C(CH(3))(CH(2)OCO-4-TEMPO)(2) (6), HC[triple bond]CCH(2)NHCO-4-TEMPO (7), and HC[triple bond]CCH(2)OCO-4-TEMPO (8) were polymerized to afford novel polymers containing the TEMPO radical at high densities. Monomers 1, 3-6, and 8 provided polymers with average molecular weights of 10 000-136 500 in 62-99 % yield in the presence of a rhodium catalyst, whereas monomers 2 and 7 gave insoluble polymers in 100 % yield. The formed polymers were thermally stable up to approximately 274 degrees C according to thermogravimetric analysis (TGA). All the TEMPO-containing polymers demonstrated reversible charge/discharge processes, whose discharge capacities were 21.3-108 A h kg(-1). In particular, the capacity of poly(1)-, poly(4)-, and poly(5)-based cells reached 108, 96.3, and 89.3 A h kg(-1), respectively, which practically coincided with their theoretical values.     

Anthraquinones with antiplasmodial activity from the roots of Rennellia elliptica Korth. (Rubiaceae)

Dichloromethane root extract of Rennellia elliptica Korth. showed strong inhibition of Plasmodium falciparum growth in vitro with an IC?? value of 4.04 μg/mL. A phytochemical study of the dichloromethane root extract has led to the isolation and characterization of a new anthraquinone, 1,2-dimethoxy-6-methyl-9,10-anthraquinone (1), and ten known anthraquinones: 1-hydroxy-2-methoxy-6-methyl-9,10-anthraquinone (2), nordamnacanthal (3), 2-formyl-3-hydroxy-9,10-anthraquinone (4), damnacanthal (5), lucidin-ω-methyl ether (6), 3-hydroxy-2-methyl-9,10-anthraquinone (7), rubiadin (8), 3-hydroxy-2-methoxy-6-methyl-9,10-anthraquinone (9), rubiadin-1-methyl ether (10) and 3-hydroxy-2-hydroxymethyl-9,10-anthraquinone (11). Structural elucidation of all compounds was accomplished by modern spectroscopic methods, notably 1D and 2D NMR, IR, UV and HREIMS. The new anthraquinone 1, 2-formyl-3-hydroxy-9,10-anthraquinone (4) and 3-hydroxy-2-methyl-9,10-anthraquinone (7) possess strong antiplasmodial activity, with IC?? values of 1.10, 0.63 and 0.34 μM, respectively.     

Zinc(II) ortho-hydroxyphenylhydrazo-β-diketonate complexes and their catalytic ability towards diastereoselective nitroaldol (Henry) reaction

The zinc(II) complexes with ortho-hydroxy substituted arylhydrazo-β-diketonates [Zn(2)(CH(3)OH)(2)(μ-L(1))(2)] (5), [Zn{(CH(3))(2)SO}(H(2)O)(L(2))] (6), [Zn(2)(H(2)O)(2)(μ-L(3))(2)] (7) and [Zn(H(2)O)(2)(L(4))]·H(2)O (8) were synthesized by reaction of a zinc(II) salt with the appropriate hydrazo-β-diketone, HO-2-C(6)H(4)-NHN=C{C(=O)CH(3)}(2) (H(2)L(1), 1), HO-2-O(2)N-4-C(6)H(3)-NHN=C{C(=O)CH(3)}(2) (H(2)L(2), 2), HO-2-C(6)H(4)-NHN=CC(=O)CH(2)C(CH(3))(2)CH(2)C(=O) (H(2)L(3), 3) or HO-2-O(2)N-4-C(6)H(3)-NHN=[CC(=O)CH(2)C(CH(3))(2)CH(2)C(=O) (H(2)L(4), 4). They were fully characterized, namely by X-ray diffraction analysis that disclosed the formation of extensive H-bonds leading to 1D chains (5 and 6), 2D layers (7) or 3D networks (8). The thermodynamic parameters of the Zn(II) reaction with H(2)L(2) in solution, as well as of the thermal decomposition of 1-8 were determined. Complexes 5-8 act as diastereoselective catalysts for the nitroaldol (Henry) reaction. The threo/erythro diastereoselectivity of the β-nitroalkanol products ranges from 8:1 to 1:10 with typical yields of 80-99%, depending on the catalyst and substrate used.     

Spectroscopic, structural, computational and (spectro)electrochemical studies of icosahedral carboranes bearing fluorinated aryl groups

The icosahedral carboranes 1-C(6)F(5)-2-Ph-1,2-closo-C(2)B(10)H(10) (1), 1-(4'-F(3)CC(6)H(4))-2-Ph-1,2-closo-C(2)B(10)H(10) (2), 1,2-(4'-F(3)CC(6)H(4))(2)-1,2-closo-C(2)B(10)H(10) (3), 1-(4'-H(3)CC(6)F(4))-2-Ph-1,2-closo-C(2)B(10)H(10) (4), 1-(4'-F(3)CC(6)F(4))-2-Ph-1,2-closo-C(2)B(10)H(10) (5), 1,2-(4'-F(3)CC(6)F(4))(2)-1,2-closo-C(2)B(10)H(10) (6), 1,7-(4'-F(3)CC(6)F(4))(2)-1,7-closo-C(2)B(10)H(10) (7) and 1,12-(4'-F(3)CC(6)F(4))(2)-1,12-closo-C(2)B(10)H(10) (8), with fluorinated aryl substituents on cage carbon atoms, have been prepared in good to high yields and characterised by microanalysis, (1)H, (11)B and (19)F NMR spectroscopies, mass spectrometry, single-crystal X-ray diffraction and (spectro)electrochemistry. By analysis of <δ(11)B>, the weighted average (11)B chemical shift, a ranking order for the ortho carboranes 1-6 is established based on the combined electron-withdrawing properties of the C-substituents, and is in perfect agreement with that established independently by electrochemical study. In a parallel computational study the effects of a wide range of different substituents on the redox properties of carboranes have been probed by comparison of ΔE values, where ΔE is the energy gap between the DFT-optimised [7,9-R(2)-7,9-nido-C(2)B(10)](2-) anion and its DFT-optimised basket-shaped first oxidation product. The overall conclusion from the NMR spectroscopic, electrochemical and computational studies is that strongly electron withdrawing substituents significantly stabilise [7,9-nido-C(2)B(10)](2-) dianions with respect to oxidation, and that the best practical substituent is 4-F(3)CC(6)F(4). Thus attention focussed on the reduction of 1,2-(4'-F(3)CC(6)F(4))(2)-1,2-closo-C(2)B(10)H(10), compound 6. The sequence 6/[6](-)/[6](2-) appears reversible on the cyclic voltammetric timescale but on the longer timescale of macroelectrolysis the radical anion is only partially stable. EPR study of the electrogenerated monoanions from the ortho-carboranes 1-6 confirms the cage-centred nature of the redox processes. In contrast, the reduction of the meta- and para-carboranes 7 and 8, respectively, appears to be centred on the aromatic substituents, a conclusion supported by the results of DFT calculation of the LUMOs of compounds 6-8. Bulk 2-electron reduction of 6 affords a dianion which is remarkably stable to reoxidation, surviving for several hours in the open laboratory in the absence of halogenated solvents.     

人面果树皮中口 山 酮 化合物及其DPPH自由基的清除活性

从人面果乙酸乙酯提取物中分离出5个新的口 山 酮 化合物garcinenone A (1), B (3), C (4), D (7) and E (8)和7个已知化合物,其结构经过波谱技术,特别是2D-NMR技术来鉴定。Jacareubin (2), 1,4,6-trihydroxy-5-methoxy-7-(3-methyl-2-buteny1)xanthone (6), subeliptenone B (11) 和symphoxanthone (12)为首次从该植物中分离出来。在DPPH自由基的清除活性实验中,所有的化合物都显示抗氧化活性,其IC50的值在 6.0-23.2 mM。结果表明人面果是潜在的有前景的天然抗氧化剂。     

Dereplication coupled with in vitro antioxidant assay of two flavonoid glycosides from Diospyros peregrina fruit

Diospyros peregrina is an edible seasonal fruit found in coastal West Bengal, India. The fruits have been reported to possess a significant antioxidant activity. In this study, the aim was to isolate the lead compound responsible for the above-mentioned activity. The aqueous extract of D. peregrina fruit was subjected to dereplication coupled with an in?vitro 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging assay. The n-butanol fraction of the aqueous extract of D. peregrina fruit exhibited significant antioxidant activity (IC(50), 131.10?μg?mL(-1)) as compared with the parent extract (IC(50), 285.15?μg?mL(-1)). The n-butanol fraction was subjected to silica gel column chromatographic separation coupled with a chemo-autographic study of column eluents, employing ethanolic DPPH as a spraying reagent. Two bioactive flavonoid glycosides, namely luteoline-4'-methyl-ether-7-O-glucoside and quercetin-3-O-(glucosyl)-glucoside, were identified to exhibit IC(50) values of 74.04 and 65.78?μg?mL(-1), respectively in the DPPH assay.     

Efficient synthesis of 2-modified 1alpha,25-dihydroxy-19-norvitamin D3 with Julia olefination: high potency in induction of differentiation on HL-60 cells

Six novel 2-substituted analogues of 1alpha,25-dihydroxy-19-norvitamin D(3), 6a,b-8a,b, were efficiently synthesized utilizing (-)-quinic acid as the A-ring precursor. The C2-modified A-rings were prepared as 4-alkylated (3R,5R)-3,5-dihydroxycyclohexanones 12-15 from (-)-quinic acid based on radical allylation at the C4 position of methyl (-)-quinicate. The new type of the CD-ring coupling partner 23 was synthesized from 25-hydroxy Grundmann's ketone 19 to apply to the modified Julia olefination to construct a diene unit between the A-ring and the CD-ring. The coupling yields, including a deprotection step, were 47-62%. After the separation of the diastereomers based on C2 stereochemistry, the structure (2alpha or 2beta) was determined by (1)H NMR experiments and compared to DeLuca's 2-methyl- and 2-ethyl-1alpha,25-dihydroxy-19-norvitamin D(3). Thus, the synthesized 2alpha-(3-hydroxypropyl)-1alpha,25-dihydroxy-19-norvitamin D(3) (8a) showed almost the same potency in binding to the bovine thymus vitamin D receptor (VDR) as the natural hormone 1, while its beta-isomer 8b had only a 3% affinity. Both 2alpha-allyl- and 2alpha-propyl-1alpha,25-dihydroxy-19-norvitamin D(3) (6a and 7a) and their 2beta-analogues (6b and 7b) possessed a weak affinity for the VDR. The strong VDR ligand 8a was ca. 36-fold more potent in induction of HL-60 cell differentiation than 1, and interestingly, even the weaker ligand 8b showed a 6.7-fold higher potency in the cell differentiation activity than that of 1.     

DPPH radical scavenging and xanthine oxidase inhibitory activity of Terminalia macroptera leaves

From a methanol extract of the leaves of the Malian medicinal tree Terminalia macroptera, cis-polyisoprene (1), chebulic acid trimethyl ester (2), methyl gallate (3), shikimic acid (4), corilagin (5), rutin (6), narcissin (7), chebulagic acid (8) and chebulinic acid (9), were isolated. Cispolyisoprene (1) was the major non-polar constituent. The novel compound 2 showed high radical scavenging activity (IC50 4.7 microg/mL), but was inactive as xanthine oxidase inhibitor. The major substituent of the crude extract, substance 5, showed a high radical scavenger effect (IC50 2.7 microg/mL) and weak xanthine oxidase inhibition (IC50 ca 105 microg/mL). The antioxidant and radical scavenging effects of some of the substances identified in this study may to some extent explain the medical use of this tree in West Africa.     

Iridoid glycosides from Globularia davisiana

From the ethanolic extract of the aerial parts of Globularia davisiana, a new iridoid glycoside, davisioside (1), was isolated. Davisioside (1) comprises a rare iridoid aglycone structure with a saturated double bond between C-3 and C-4. Nine known iridoid glycosides, asperuloside (2), alpinoside (3), geniposide (4), globularin (5), globularicisin (6), 10-O-benzoylcatalpol (7), lytanthosalin (8), melampyroside (9), agnuside (10), and three known phenylethanoid glycosides, verbascoside, isoacteoside and leucosceptoside A were also isolated and characterized. The structures of the isolates were established by spectroscopic methods (one-dimensional (1D)- and two-dimensional (2D)-NMR, MS).     

Novel dammarane-type glycosides from Gynostemma pentaphyllum

Three new dammarane glycosides (1-3), together with five known compounds, gypenoside LXIX (4), gylongiposide I (5), gypenoside XLVIII (6), allantion (7) and vitexin (8) were isolated from the MeOH extract of the aerial parts of Gynostemma pentaphyllum. Compounds 5, 7, and 8 were isolated from this plant for the first time. Their structures were elucidated by 1D and 2D NMR spectra interpretation as well as by chemical degradation.