- Understanding the role played by protic ionic liquids (PILs) and the substituent effect for enhancing the generation of: Z-cinnamic acid derivatives
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Photoisomerization of a series of substituted E-cinnamic acids in MeCN in their acid forms and as their corresponding protic ionic liquids (PILs) with light of 300 nm is studied. The nature, strength, number, and position effects of substituents on the photochemical behavior of E-cinnamic derivatives are investigated. The photosensitization of the reaction in the presence of Michler's ketone is also studied at 366 nm and it demonstrates that the triplet-excited state is involved in the reaction. As the presence of n-butylamine needed to form the PILs significantly increases the photoproduct yields in all cases, the role of the PILs is also discussed. Thus, understanding of these fundamental aspects has allowed us to establish an excellent and practical synthetic protocol for successfully synthesizing Z-cinnamic acids. This journal is
- Rodríguez, Roció B.,Rodríguez, Roció B.,Zapata, Ramiro L.,Salum, Mariá L.,Salum, Mariá L.,Erra-Balsells, Rosa,Erra-Balsells, Rosa
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p. 819 - 830
(2020/07/03)
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- Four New Flavonoids Isolated from the Aerial Parts of Cadaba rotundifolia Forssk. (Qadab)
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Cadaba rotundifolia (Forssk.) (family: Capparaceae; common name: Qadab) is one of four species that grow in the Red Sea costal region in the Kingdom of Saudi Arabia. The roots and leaves of C. rotundifolia is traditionally used to treat tumors and abscesses in Sudan. A previous phytochemical study of the roots yielded a quaternary alkaloid, but no report on chemical constituents of the aerial parts of the C. rotundifolia growing in Saudi Arabia has been issued so far. Oxidative stress and advanced glycation end products (AGEs) are thought as causal factors in many degenerative diseases, such as Alzheimer's disease, diabetes, atherosclerosis and aging. In this study, a total of twenty compounds, including four previously undescribed acylated kaempferol glucosides, were isolated from the aerial parts of C. rotundifolia collected in Saudi Arabia. These new compounds were identified as kaempferol 3-O-[2-O-(trans-feruloyl)-3-O-β-d-glucopyranosyl]-β-d-glucopyranoside (1), kaempferol 3-O-β-neohesperidoside-7-O-[2-O-(cis-p-coumaroyl)-3-O-β-d-glucopyranosyl]-β-d-glucopyranoside (2), kaempferol 3-O-[2,6-di-O-α-l-rhamnopyranosyl]-β-d-glucopyranoside-7-O-[6-O-(trans-feruloyl)]-β-d-glucopyranoside (3) and kaempferol 3-O-[2,6-di-O-α-l-rhamnopyranosyl]-β-d-glucopyranoside-7-O-[6-O-(trans-p-coumaroyl)]-β-d-glucopyranoside (4). Their structures were established based on UV-visible, 1D, 2D NMR, and HR-ESI-MS analyses. Of the assayed compounds, 17 and 18 showed potent radical scavenging activity with IC50 values of 14.5 and 11.7 μM, respectively, and inhibitory activity toward AGEs together with compound 7 with IC50 values 96.5, 34.9 and 85.5 μM, respectively.
- Al-Hamoud, Gadah Abdulaziz,Orfali, Raha Saud,Sugimoto, Sachiko,Yamano, Yoshi,Alothyqi, Nafee,Alzahrani, Ali Mohammed,Matsunami, Katsuyoshi
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- Flavonoid glycosides from Sedum bulbiferum
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The MeOH extract from dried whole Sedum bulbiferum MAKINO (Crassulaceae) plants yielded 34 compounds, including six new flavonoid glycosides and 28 known compounds. The structures of new compounds were established using NMR, Mass spectroscopic analysis an
- Warashina, Tsutomu,Miyase, Toshio
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p. 1199 - 1204
(2017/12/26)
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- Stability of Hydroxycinnamic Acid Derivatives, Flavonol Glycosides, and Anthocyanins in Black Currant Juice
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The stability of phenolic compounds was followed in black currant juice at ambient temperatures (in light and in dark conditions) and at +4 °C for a year. Analyses were based on high-performance liquid chromatography-diode-array detection-electrospray ionization-mass spectrometry (or tandem mass spectrometry) and high-performance liquid chromatography-diode-array detection-electrospray ionization-quadrupole time-of-flight mass spectrometry methods supported by nuclear magnetic resonance after selective high-performance liquid chromatography isolation. Altogether, 43 metabolites were identified, of which 2-(Z)-p-coumaroyloxymethylene-4-β-d-glucopyranosyloxy-2-(Z)-butenenitrile, 2-(E)-caffeoyloxymethylene-4-β-d-glucopyranosyloxy-2-(Z)-butenenitrile, 1-O-(Z)-p-coumaroyl-β-d-glucopyranose, (Z)-p-coumaric acid 4-O-β-d-glucopyranoside, and (Z)-p-coumaric acid were novel findings in black currant juice. Hydroxycinnamic acid derivatives degraded 20-40% at room temperature during one year of storage, releasing free hydroxycinnamic acids. O-Glucosides of hydroxycinnamic acid compounds were the most stable, followed by O-acylquinic acids, acyloxymethyleneglucosyloxybutenenitriles, and O-acylglucoses. Light induced the isomerization of (E)-coumaric acid compounds into corresponding Z-isomers. Flavonol glycosides stayed fairly stable. Flavonol aglycones were derived mainly from malonylglucosides. Over 90% of anthocyanins were lost at room temperature in a year, practically independent of light. Storage at low temperatures, preferably excluding light, is necessary to retain the original composition of phenolic compounds.
- M?kil?, Leenamaija,Laaksonen, Oskar,Alanne, Aino-Liisa,Kortesniemi, Maaria,Kallio, Heikki,Yang, Baoru
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p. 4584 - 4598
(2016/07/06)
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- Phenolic glycosides from the twigs of Salix glandulosa
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As a part of an ongoing search for bioactive constituents from Korean medicinal plants, the phytochemical investigations of the twigs of Salix glandulosa afforded 12 new phenolic glycosides (1-12) and a known analogue (13). The structures of 1-13 were characterized by a combination of NMR methods (1H and 13C NMR, 1H-1H COSY, HMQC, and HMBC), chemical hydrolysis, and GC/MS. The absolute configuration of 13 [(1R,2S)-2-hydroxycyclohexyl-2′-O-trans-p-coumaroyl-β-d- glucopyranoside] was determined for the first time. Compounds 1-3, 6, and 7 exhibited inhibitory effects on nitric oxide production in lipopolysaccharide- activated murine microglial cells (IC50 values in the range 6.6-20.5 μM).
- Kim, Chung Sub,Kwon, Oh Wook,Kim, Sun Yeou,Choi, Sang Un,Kim, Jae Yoon,Han, Ji Young,Choi, Soo Im,Choi, Jong Gil,Kim, Ki Hyun,Lee, Kang Ro
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p. 1955 - 1961
(2014/10/16)
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- Structures of acylated sucroses from the flower buds of Prunus mume
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Seven new acylated sucroses, mumeoses P-V, were isolated from the flower buds of Prunus mume, cultivated in Zhejiang province, China. Their chemical structures were elucidated on the basis of chemical and physicochemical evidence. Moreover, mumeoses C, D,
- Fujimoto, Katsuyoshi,Nakamura, Seikou,Matsumoto, Takahiro,Ohta, Tomoe,Yoshikawa, Masayuki,Ogawa, Keiko,Kashiwazaki, Eri,Matsuda, Hisashi
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p. 481 - 487
(2014/08/05)
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- Photo-isomerization upshifts the pka of the photoactive yellow protein chromophore to contribute to photocycle propagation
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The influence of chromophore structure on the protonation constant of the Photoactive Yellow Protein chromophore is explored with isolated para-coumaric acid (pCA) and thiomethyl-para-coumaric acid model chromophores in solution. pH titration coupled with visible absorption spectra of the trans and photogenerated cis conformer of isolated pCA demonstrates that the isomerization of the chromophore increases the pKa of the phenolate group by 0.6 units (to 10.1 ± 0.22). Formation of the pCA thioester reduces the pKa of the phenolic group by 0.3 units (from 9.5 ± 0.15 to 9.2 ± 0.16). Unfortunately, a macroscopic cis-TMpCA population was not achieved via photoexcitation. Both trends were explained with electronic structure calculations including a Natural Bond Orbital analysis that resolves that the pKa upshift for the cis configuration is attributed to increased Columbic repulsion between the coumaryl tail and the phenolate moieties. This structurally induced pKa upshift after isomerization is argued to aid in the protonation of the chromophore within the PYP protein environment and the subsequent propagation of the photocycle response and in vivo photo-activity.
- Naseem, Sadia,Laurent, Adele D.,Carroll, Elizabeth C.,Vengris, Mikas,Kumauchi, Masato,Hoff, Wouter D.,Krylov, Anna I.,Larsen, Delmar S.
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- Acylated sucroses and acylated quinic acids analogs from the flower buds of Prunus mume and their inhibitory effect on melanogenesis
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The methanolic extract from the flower buds of Prunus mume, cultivated in Zhejiang Province, China, showed an inhibitory effect on melanogenesis in theophylline-stimulated B16 melanoma 4A5 cells. From the methanolic extract, five acylated sucroses, mumeoses A-E, and three acylated quinic acid analogs, 5- O-(E)-p-coumaroylquinic acid ethyl ester, and mumeic acid-A and its methyl ester, were isolated together with 13 known compounds. The chemical structures of the compounds were elucidated on the basis of chemical and physicochemical evidence. Inhibitory effects of the isolated compounds on melanogenesis in theophylline-stimulated B16 melanoma 4A5 cells were also investigated. Acylated quinic acid analogs substantially inhibited melanogenesis. In particular, 5-O-(E)-feruloylquinic acid methyl ester exhibited a potent inhibitory effect [inhibition (%): 21.5 ± 1.0 (P 97% at 10 μM]. It is concluded that acylated quinic acid analogs are promising therapeutic agents for the treatment of skin disorders.
- Nakamura, Seikou,Fujimoto, Katsuyoshi,Matsumoto, Takahiro,Nakashima, Souichi,Ohta, Tomoe,Ogawa, Keiko,Matsuda, Hisashi,Yoshikawa, Masayuki
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p. 128 - 136
(2013/10/21)
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- Triacylated peonidin 3-sophoroside-5-glucosides from the purple flowers of Moricandia ramburii Webb.
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Triacylated peonidin 3-sophoroside-5-glucosides were isolated from the purple flowers of Moricandia ramburii Webb. (Family: Brassicaceae), and determined to be peonidin 3-O-[2-O-(2-O-(trans-feruloyl)-glucosyl)-6-O-(trans-p- coumaroyl)-glucoside]-5-O-[6-O-(malonyl)-glucoside] (1), peonidin 3-O-[2-O-(2-O-(trans-feruloyl)-glucosyl)-6-O-(cis-p-coumaroyl)-glucoside] -5-O-[6-O-(malonyl)-glucoside] (2) and peonidin 3-O-[2-O-(2-O-(trans-sinapoyl)- glucosyl)-6-O-(trans-p-coumaroyl)-glucoside]-5-O-[6-O-(malonyl)-glucoside] (3), respectively, by chemical and spectroscopic methods. In addition, one known acylated cyanidin glycoside, cyanidin 3-O-[2-O-(2-O-(trans-feruloyl)-glucosyl)- 6-O-(trans-p-coumaroyl)-glucoside]-5-O-[6-O-(malonyl)-glucoside] (4), was also identified in the flowers. Peonidin glycosides have not been reported hitherto in floral tissues in to Brassicaceae.
- Tatsuzawa, Fumi,Ito, Kanako,Muraoka, Hiroki,Namauo, Toshiharu,Kato, Kazuhisa,Takahata, Yoshihito,Ogawa, Satoshi
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experimental part
p. 73 - 77
(2012/06/30)
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- Photo-induced phase transition from multilamellar vesicles to wormlike micelles
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A novel complex fluid system of tetradecyldimethylamine oxide (C 14DMAO) mixed with para-coumaric acid (PCA) in water was investigated. The phase behavior was determined in detail; one observed sequentially the L1-phase (micelles), two-phase L1/L α, Lα-phase (vesicles), and L α/precipitates with increasing PCA concentration at constant concentration of C14DMAO. The samples in the regions of micelles and vesicles were characterized by rheological measurements and cryo-TEM observations. Fascinatingly, we found a phase transition from vesicles to wormlike micelles performed via UV-light irradiation. The properties and structures after UV-light irradiation were determined by rheological measurements and cryo-TEM observations to demonstrate the phase transition. To the best of our knowledge, this transition is rarely reported, which could provide a better understanding of the phase transition via light irradiation and find potential applications in drug delivery, biochemistry, and the oilfield industry.
- Wang, Dong,Dong, Renhao,Long, Pangfeng,Hao, Jingcheng
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scheme or table
p. 10713 - 10719
(2012/05/19)
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- Acylated phenylethanoid oligoglycosides with hepatoprotective activity from the desert plant Cistanche tubulosa1
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The methanolic extract from fresh stems of Cistanche tubulosa (Orobanchaceae) was found to show hepatoprotective effects against d-galactosamine (d-GalN)/lipopolysaccharide (LPS)-induced liver injury in mice. From the extract, three new phenylethanoid oligoglycosides, kankanosides H1 (1), H2 (2), and I (3), were isolated together with 16 phenylethanoid glycosides (4-19) and two acylated oligosugars (20, 21). The structures of 1-3 were determined on the basis of spectroscopic properties as well as of chemical evidence. Among the isolates, echinacoside (4, IC50 = 10.2 μM), acteoside (5, 4.6 μM), isoacteoside (6, 5.3 μM), 2′-acetylacteoside (8, 4.8 μM), and tubuloside A (10, 8.6 μM) inhibited d-GalN-induced death of hepatocytes. These five isolates, 4 (31.1 μM), 5 (17.8 μM), 6 (22.7 μM), 8 (25.7 μM), and 10 (23.2 μM), and cistantubuloside B1 (11, 21.4 μM) also reduced TNF-α-induced cytotoxicity in L929 cells. Moreover, principal constituents (4-6) exhibited in vivo hepatoprotective effects at doses of 25-100 mg/kg, po.
- Morikawa, Toshio,Pan, Yingni,Ninomiya, Kiyofumi,Imura, Katsuya,Matsuda, Hisashi,Yoshikawa, Masayuki,Yuan, Dan,Muraoka, Osamu
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experimental part
p. 1882 - 1890
(2010/05/18)
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- Nonaqueous photorheological fluids based on light-responsive reverse wormlike micelles
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Fluids whose flow properties can be altered by light are an emerging class of functional materials, with potential applications in microscale actuators and valves. While many such photorheological (PR) fluids have been developed over the years, most are based on specialized organized molecules that require synthesis. We have instead sought to develop PR fluids using inexpensive chemical components that are commercially available, and this approach has been successfully applied to aqueous systems. Here, we demonstrate a simple class of nonaqueous PR fluids based on the phospholipid, lecithin, and the organic derivative, para-coumaric acid (PCA). The combination of lecithin with the trans form of PCA results in reverse wormlike micelles, which are long, flexible chains that undergo entanglement, thereby giving rise to viscoelastic fluids. Upon UV irradiation, trans-PCA is photoisomerized to its cis form, which has a lower polarity and hydrogen-bonding tendency. This causes a significant reduction in the length of the micellar chains, and in turn, the fluid viscosity drops more than 1000-fold. We show that photoresponsive reverse micelles can be formed in a range of organic solvents including cyclohexane, n-alkanes, alkenes, and fatty acid esters.
- Kumar, Rakesh,Ketner, Aimee M.,Raghavan, Srinivasa R.
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experimental part
p. 5405 - 5411
(2010/11/19)
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- Photoisomerization of ionic liquid ammonium cinnamates: One-pot synthesis-isolation of Z-cinnamic acids
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Photoisomerization presents the only direct method for contra-thermodynamic E-Z isomerization of olefins. Synthetic applications of this method have been limited by its reversible nature, which leads to a photostationary-state mixture of both isomers. For the first time, a highly efficient one-pot preparation-isolation of solid ionic liquid Z-cinnamic acids by photoisomerization in acetonitrile solution of ionic liquid E-cinnamic acids is described.
- Salum, Maria L.,Robles, Cecilia J.,Erra-Balsells, Rosa
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supporting information; experimental part
p. 4808 - 4811
(2011/01/03)
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- Identification and quantification of phenolic compounds from the forage legume sainfoin (Onobrychis viciifolia)
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Phenolic compounds of sainfoin (Onobrychis viciifolia) variety Cotswold Common are assumed to contribute to its nutritive value and bioactive properties. A purified acetone/water extract was separated by Sephadex LH-20 gel chromatography. Sixty-three phen
- Regos, Ionela,Urbanella, Andrea,Treutter, Dieter
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experimental part
p. 5843 - 5852
(2010/06/17)
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- Templating photodimerization of trans-cinnamic acids with cucurbit[8]uril and γ-cyclodextrin
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(Chemical Equation Presented) Cucurbit[8]uril and γ-cyclodextrin are able to align two olefin molecules in a head-head fashion within their large cavities. Excitation of such templated olefins results in syn head-head cyclobutanes in nearly quantitative yields. The methodology revealed here works with trans-cinnamic acids that do not dimerize either in solution or in the solid state and with the ones that yield only anti head-tail dimer in the solid state.
- Pattabiraman, Mahesh,Natarajan, Arunkumar,Kaanumalle, Lakshmi S.,Ramamurthy
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p. 529 - 532
(2007/10/03)
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- Antioxidative properties of phenolic antioxidants isolated from corn steep liquor
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With the immersion of corn into dilute sulfur oxide during starch-manufacturing processes, corn steep liquor (CSL) remains as leftover material. CSL is often used for fermentation, but its components are not fully understood. To determine the properties of CSL, 12 p-coumaric acid-related compounds were isolated from an ethyl acetate extract of CSL with the guidance of antioxidative activity on the rabbit erythrocyte membrane ghost system. The activity of these compounds was compared against oxidative damages, and it was elucidated that the activity of p-coumaric acid derivatives was mainly affected by their functional groups at the 3-position and less, by the conjugated side chain. Moreover, p-coumaric acid derivatives exhibited inhibitory activity stronger than that of tocopherols and ascorbic acid on peroxynitrite-mediated lipoprotein nitration. These findings that p-coumaric acid derivatives, which might play a beneficial role against oxidative damage, exist in CSL suggest this byproduct might be a useful resource of phenolic antioxidants.
- Niwa, Toshio,Dpi, Umeyuki,Kato, Yoji,Osawa, Toshihiko
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p. 177 - 182
(2007/10/03)
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- Leaf-opening Substance in the Nyctinastic Plant, Albizzia julibrissin Durazz
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cis-p-Coumaroylagmatine (1) was isolated from Albizzia julibrissin Durazz, a nyctinastic plant, as a leaf-opening substance. The compound was quite effective for opening the plant leaves at 5 × 10-6 M at night, but was not effective for other nyctinastic plants. The bioactive fraction with leaf-closing activity was also separated from the plant extract. Although the leaf-opening activity of the plant extract changed between the day and night, the content of 1 was almost constant through a 24-h day. These results suggest that the change in content of an unknown leaf-closing factor induced balance between the two leaf-movement factors through a 24-h day.
- Ueda, Minoru,Sawai, Yoshiyuki,Shibazaki, Yuichiro,Tashiro, Chitose,Ohnuki, Takashi,Yamamura, Shosuke
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p. 2133 - 2137
(2007/10/03)
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- Xanthones, triterpenes and a biphenyl from Kielmeyera coriacea
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Analysis of the dichloromethane extracts of Kielmeyera coriacea leaves and stems by high performance liquid chromatography coupled with a photodiode array detector (LC-UV) and thermospray liquid chromatography-mass spectrometry (TSP/LC-MS) revealed the presence of several xanthones. Phytochemical investigation of these extracts resulted in the isolation and identification of ten xanthones, one biphenyl and two triterpenes. Their structures were established by chemical and spectroscopic methods (UV, EI- MS, D/CI-MS, 1H NMR, 13C NMR, HMQC and HMBC). One xanthone and two triterpenes are new compounds. Four xanthones and the biphenyl exhibited antifungal activity against the plant pathogenic fungus Cladosporium cucumerinum, while two prenylated xanthones inhibited the growth of Candida albicans.
- Garcia Cortez,Young,Marston,Wolfender,Hostettmann
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p. 1367 - 1374
(2007/10/03)
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- Photochemistry of N-phthaloyl derivatives of electron-donor-substituted amino acids
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The hydroxy substituted amino acids threonine and serine have been investigated concerning their photochemical behaviour when activated as N-phthaloyl substrates. The methyl esters 1a and 2a solely underwent cleavage of the central C-C single bond to give the glycine derivative 3 and an aldehyde fragment. C-unprotected threonine derivative 1b is converted into a series of products the composition of which depends on solvent polarity and on the electronic state. Three reaction modes were detected for the N-phthaloyl derivatives of the aryl substituted amino acids phenylalanine, tyrosine, and dihydroxyphenylalanine (DOPA): (A) decarboxylation (only for 12a), (B) β-fragmentation, and (C) ring enlargement reaction. Processes B and C are initiated by photo electron transfer (PET), as the solvent dependence revealed. The DOPA derivatives 14a and 14b are the most prominent examples due to their exclusive PET reactivity leading to type C products (18a,b) with high diastereoselectivity (90:10). PET results from the first excited singlet states of 12 and 13, whereas for compounds 14 the corresponding triplet states are involved. The correlation between photochemical reactivity and the fluorescence decay data for compounds 12a,b and 15 is discussed.
- Griesbeck,Henz,Hirt,Ptatschek,Engel,Loffler,Schneider
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p. 701 - 714
(2007/10/02)
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- Mechanistic and stereochemical study of phenylpyruvate tautomerase
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A variety of substrates and potential enol/enolate mimics for the product/transition state of the enzyme phenylpyruvate tautomerase (E.C. 5.3.2.1) have been prepared and studied. Their stereostructures have been secured by a combination of NMR spectroscopy based on vicinal H-F and H-C coupling constants and X-ray crystallography. On the basis of the inhibition by stereoisomeric substituted cinnamates, it has been concluded that the enzyme produces the thermodynamically less stable (E) enol via a syn tautomerization transition state. Free energy profiles for the reaction suggest that vinyl fluorides act as product analogues. Because amide and dicarboxylate enolate mimics are relatively poor inhibitors of the enzyme, it is believed that an enolate is not involved in the tautomerization process.
- Pirrung, Michael C.,Chen, Jrlung,Rowley, Elizabeth G.,McPhail, Andrew T.
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p. 7103 - 7110
(2007/10/02)
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- FOUR ACYLATED FLAVONOL GLYCOSIDES FROM LEAVES OF STRYCHNOS VARIABILIS
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Four new acylated flavonol glycosides have been isolated and identified from the leaves of Strychnos variabilis: quercetin 3-(4"-trans-p-coumaroyl)robinobioside-7-glucoside (variabiloside A) and its cis derivative (variabiloside B), kaempferol 3-(4"-trans-p-coumaroyl)robinobioside-7-glucoside (varibiloside C) and its cis derivative (variabiloside D).Key Word Index - Strychnos variabilis; Loginiaceae; acylated flavonol glycosides; variabilosides A, B, C, and D; DCCC.
- Brasseur, Thierry,Angenot, Luc
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p. 3331 - 3334
(2007/10/02)
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- HEMIACETALIC THAPSANE DERIVATIVES FROM THAPSIA VILLOSA VAR. MINOR
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The benzene extract from the roots of Thapsia villosa var. minor afforded six new sesquiterpene esters based on the thapsane skeleton for which the structure (1R,6R,8R,9R)-1,2,2,6,8,9-hexamethylbicyclononane is proposed.Five of these thapsane esters were hemiacetal derivatives esterified at C-1, C-3 or C-8 and the sixth is a dimeric acetal esterified at C-8.The structures of these substances were established on the basis of their spectral data and chemical behaviour, including their transformation into the same compound, 14,15-thapsanolide.Key Word Index- Thapsia villosa var. minor; Umbelliferae; hemiacetalic sesquiterpenes; 14,15-epoxythapsane esters.
- Teresa, Joaquin De Pascual,Moran, Joaquin R.,Fernandez, Alfonzo,Grande, Manuel
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p. 703 - 710
(2007/10/02)
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