Anti-oxidant constituents from Sedum takesimense

Flavonoids from the leaves and stems of Sedum japonicum var. senanense and their antioxidant activity

Twenty flavonoids (1-20) were isolated from the leaves and stems of Sedum japonicum var. senanense endemic to Japan. Among them, nine compounds were reported in nature for the first time, and identified as herbacetin 3-O-neohesperidoside-8-O-(2‴-acetylxyloside) (2), gossypetin 8-O-(2″-acetylxyloside) (4), gossypetin 8-O-(3″-acetylxyloside) (5), gossypetin 3-O-glucoside-8-O-(3‴-acetylxyloside) (9), gossypetin 3-O-glucoside-8-O-(2‴,3‴-diacetylxyloside) (10), gossypetin 3-O-neohesperidoside-8-O-xyloside (11), gossypetin 3-O-neohesperidoside-8-O-(2⁗-acetylxyloside) (12), gossypetin 3-O-neohesperidoside-8-O-(3⁗-acetylxyloside) (13) and gossypetin 3-O-glucoside-8-O-xylofuranoside (14) by UV spectral survey, HR-MS, LC-MS, acid hydrolysis, NMR including 1H and 13C NMR, COSY, NOESY, HSQC and HMBC. Moreover, nine major flavonoids were surveyed for antioxidant activity by H-ORAC method. As the results, gossypetin 3-O-glucoside-8-O-(2‴-acetylxyoside) (8) showed the highest antioxidant activity. Conversely, gossypetin 3-O-neohesperidoside-8-O-xyloside (11) and gossypetin 3-O-neohesperidoside-8-O-(2⁗-acetylxyloside) (12) which attach neohesperidose showed the lowest values.

Flavonoids from Sedum japonicum subsp. oryzifolium (Crassulaceae)

Twenty-two flavonoids were isolated from the leaves and stems of Sedum japonicum subsp. oryzifolium (Crassulaceae). Of these compounds, five flavonoids were reported in nature for the first time, and identified as herbacetin 3-O-xyloside-8-O-glucoside, herbacetin 3-O-glucoside-8-O-(2′′′-acetylxyloside), gossypetin 3-O-glucoside-8-O-arabinoside, gossypetin 3-O-glucoside-8-O-(2′′′-acetylxyloside) and hibiscetin 3-O-glucoside-8-O-arabinoside via UV, HR-MS, LC-MS, acid hydrolysis and NMR. Other seventeen known flavonoids were identified as herbacetin 3-O-glucoside-8-O-arabinoside, herbacetin 3-O-glucoside-8-O-xyloside, gossypetin 3-O-glucoside-8-O-xyloside, quercetin, quercetin 3-O-glucoside, quercetin 3-O-xylosyl-(1→2)-rhamnoside-7-O-rhamnoside, quercetin 3-O-rhamnoside-7-O-glucoside, kaempferol, kaempferol 3-O-glucoside, kaempferol 7-O-rhamnoside, kaempferol 3,7-di-O-rhamnoside, kaempferol 3-O-glucoside-7-O-rhamnoside, kaempferol 3-O-glucosyl-(1→2)-rhamnoside-7-O-rhamnoside, kaempferol 3-O-xylosyl-(1→2)-rhamnoside, kaempferol 3-O-xylosyl-(1→2)-rhamnoside-7-O-rhamnoside, myricetin 3-O-glucoside and cyanidin 3-O-glucoside. Some flavonol 3,8-di-O-glycosides were found in Sedum japonicum subsp. oryzifolium as major flavonoids in this survey. They were presumed to be the diagnostic flavonoids in the species. Flavonoids were reported from S. japonicum for the first time.

Synergistic Antibacterial Activity of an Active Compound Derived from Sedum takesimense against Methicillin-Resistant Staphylococcus aureus and Its Clinical Isolates

There are a growing number of reports of hospital-acquired infections caused by pathogenic bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA). Many plant products are now being used as a natural means of exploring antimicrobial agents against different types of human pathogenic bacteria. In this research, we sought to isolate and identify an active molecule from Sedum takesimense that has possible antibacterial activity against various clinical isolates of MRSA. NMR analysis revealed that the structure of the HPLC-purified compound was 1,2,4,6-tetra-O-galloyl-glucose. The minimum inhibitory concentration (MIC) of different extract fractions against numerous pathogenic bacteria was determined, and the actively purified compound has potent antibacterial activity against multidrug-resistant pathogenic bacteria, i.e., MRSA and its clinical isolates. In addition, the combination of the active compound and β-lactam antibiotics (e.g., oxacillin) demonstrated synergistic action against MRSA, with a fractional inhibitory concentration (FIC) index of 0.281. The current research revealed an alternative approach to combating pathogenesis caused by multi-drug resistant bacteria using plant materials. Furthermore, using a combination approach in which the active plant-derived compound is combined with antibiotics has proved to be a successful way of destroying pathogens synergistically.

Synthesis, biological evaluation (antioxidant, antimicrobial, enzyme inhibition, and cytotoxic) and molecular docking study of hydroxy methoxy benzoin/benzil analogous

In this work, due to the biological activity evaluation, a series of hydroxy methoxy benzoins (1-8), benzils (10-16) and methoxy benzoin/benzil-O-β-d-glucosides (17-28) were synthesized. Antioxidant (FRAP, CUPRAC, DPPH), antimicrobial (16 microorganisms, and two yeast), enzyme inhibition (α-amylase, α-glucosidase, AChE, BChE, and tyrosinase) of all synthesized benzoin/benzil analogs were investigated. Benzoins (1-8) showed the most effective antioxidant properties compared to all three methods. Compound 28 against α-amylase, compound 9 against α-glucosidase, compound 11 against AChE, compound 2 against BChE, and compound 13 against tyrosinase showed the best activities with the better or similar IC₅₀ values as used standards. Hydroxy methoxy benzoin compounds (1-8) among all four groups were seen as the most effective against the tested microorganism. Molecular docking analysis showed that all tested compounds 1-28 (0.01-2.22 µM) had the best binding affinity against AChE enzyme. Cytotoxic effects of the many of compounds (1-16, 21, and 24) also investigated and it was found that they caused different effects in different cells. The LDH tests of compounds 1a + b, 4, 7, 8, 9, 11, 12, 21, and 24, seemed to be effective compared to the positive control cisplatin. The cytotoxicity of compounds 6 (9.24%) for MCF7 cancer cells, 8 (5.16%) and 4 (8.26%) for HT29 cancer cells, 24 (9.84%) for Hep3B cells and 8 (8.52%), 7 (5.70%), 4 (6.94) and 9 (7.22%) for C6 cells were at normal values. And also cytotoxic activity of four compounds (5, 9, 21, and 24) among the all synthetic groups, were evaluated to the HeLa and RPE. Compound 5 showed anticancer activity on HeLa and RPE cancer cells as much as or better than cisplatin which was used as standard.

Photochemoprotective Potential of the Ethyl Acetate Fraction from Eugenia hiemalis Leaves and Its 2,6-Di-O-galloylarbutin Isolate Against UVB-Induced Photodamage

Intense and constant exposure to UVB radiation can lead to inflammation and oxidative stress, which are associated with many cutaneous disorders, including photoaging and skin cancer. Antioxidant plant materials that are rich in polyphenols, such as the ethyl acetate fraction (EAF) from Eugenia hiemalis leaves, and phenolic compounds represent a promising approach to protect the skin against UVB-induced damage. The present study evaluated the photochemoprotective potential of the EAF and its 2,6-di-O-galloylarbutin (1) isolate. The EAF and the phenolic antioxidant (1) reduced UVB-induced L929 fibroblast death. The EAF prevented UVB-induced damage in fibroblasts by inhibiting the intracellular production of reactive oxygen species and lipid peroxidation, especially in pretreated cells. Topical treatment with an emulsion with 1% EAF prevented/attenuated UVB-induced inflammation and oxidative stress in the skin in hairless mice by controlling the increase in myeloperoxidase activity, reducing superoxide anion production, maintaining radical-scavenging ability and ferric reducing power, and controlling the depletion of reduced glutathione and catalase levels. The EAF also inhibited the increase in epidermal thickness, mast cell infiltration, the number of sunburn cells and collagen fiber destruction that were triggered by UVB. The in vitro and in vivo results indicated that the EAF is a bioactive agent that is able to protect the skin against the harmful effects of UVB.

Sedum takesimense Protects PC12 Cells against Corticosterone-Induced Neurotoxicity by Inhibiting Neural Apoptosis

Neuronal cell death induced by chronic stress in the central nervous system is a cause of neurological dysfunction. We investigated the neuroprotective potential of a water extract of S. takesimense (WEST) against corticosterone-induced apoptosis in PC12 cells and the possible underlying mechanisms. Cells were pretreated with 50 µg/mL of WEST to evaluate its neuroprotective effect based on endoplasmic reticulum (ER) stress inhibition and mitochondrial function improvement. Pretreatment with WEST prevented corticosterone-induced injury in PC12 cells, resulting in increased cell survival, decreased lactate dehydrogenase (LDH) release, and potent apoptosis inhibition by a reduction in apoptotic nuclei demonstrated by Hoechst 33342 and propidium iodide (PI) double staining, and TUNEL staining. WEST strongly attenuated calcium (Ca²⁺) elevation, inducing the closure of mitochondrial permeability transition pores (mPTPs), which were opened by corticosterone. It also stabilized mitochondrial membrane potential (MMP) loss and inhibited the corticosterone-induced decrease in adenosine triphosphate (ATP) levels. Furthermore, the increased reactive oxygen species (ROS) production induced by corticosterone was prevented in PC12 cells treated with WEST. WEST also downregulated the expression of glucose-regulated protein 78 (GRP78), growth arrest- and DNA damage-inducible gene 153 (GADD153), the pro-apoptotic protein Bcl-2-associated X (Bax), cytochrome c, cysteine-aspartic protease (caspase)-9, and caspase-3, and upregulated the expression of the anti-apoptotic protein B-cell lymphoma 2 (Bcl-2). Thus, WEST exerts a neuroprotective effect by inhibiting the apoptosis pathway in ER stress and the mitochondrial dysfunction induced by corticosterone. These results demonstrate that WEST reduces neuronal damage from the neurotoxicity caused by chronic stress.

Lignan Constituents from the Fruits of Viburnum macrocephalum f. keteleeri and Their α-Amylase, α-Glucosidase, and Protein Tyrosine Phosphatase 1B Inhibitory Activities

Eight previously undescribed lignan glycosides, viburmacrosides A-H (1-8), and seven known analogues (9-15) were isolated from Viburnum macrocephalum f. keteleeri fruits through bioactivity-guided fractionation. Their structures and absolute configurations were elucidated by extensive spectroscopic analyses and chemical evidence. Using the well-recognized carbohydrate-hydrolyzing enzymes α-amylase and α-glucosidase, as well as the promising protein tyrosine phosphatase 1B (PTP1B), as inhibitory targets, all isolated compounds were tested for their antidiabetic potential in vitro. Compound 4 displayed potent inhibitory activities with IC₅₀ values of 9.9 ± 0.6 and 8.9 ± 0.5 μM against α-glucosidase and PTP1B, respectively. The enzymatic kinetics results suggested that compound 4 competitively inhibited α-glucosidase while it suppressed α-amylase and PTP1B in the mixed-type manner. These findings supported that V. macrocephalum f. keteleeri fruits may be a new functional food resource with antidiabetic potential.

In vitro antioxidant and antinociceptive properties of Porphyra vietnamensis

Background: Current investigation explores the anti-oxidant and antinociceptive potential of edible seaweed namely Porphyra vietnamensis.

Methods: Radical scavenging and antinociceptive potential of ethanolic (EE), aqueous (AE), acetone (ACE) and chloroform (CE) fractions were determined using various models and assays. Writhing, formalin, hot plate, acetic acid induce response models were performed to determine antinociceptive activity whereas different assays have been used to determine antioxidant potential.

Results: Among the various fractions, ACE showed maximum biological activity. In DPPH assay half maximal inhibitory concentration (IC50) was found to be 0.470 ug/ml (DPPH assay), 0.381 jug/m/ (H2O2 assay), 0.470 ug/ml (super oxide assay), 0.591ug/ml (lipid peroxidation) and 0.430 ug/ml (nitric oxide assay). However, comparatively the TPC was more in EE (977.0 mg GAE/gm DW).

Conclusion: It was concluded that acetone fraction of Porphyra showed marked antinociceptive and antioxidant activities, however pharmacological and chemical investigations are required to identify principle compounds responsible for activities and characterize their respective mechanism(s) for respective actions.

A new phenolic compound from Phedimus middendorffianus with antiproliferative activity

A new phenolic compound (1) and together with 12 known compounds-eight flavonoids (2 ∼ 9), two phenolic compounds (10 and 11) and two benzoic acid (12 and 13)-were isolated from Phedimus middendorffianus (Maxim.). The structures of all compound were determined on the basis of spectroscopic (MS and NMR) analyses. Compounds 4, 5, 7 and 11 ∼ 13 were showed anti-proliferative activities against MCF-7 than PC-3 cell line. Also compound 12 and 13 showed the significant cytotoxic activities against two cancer cell lines, PC-3 and MCF-7.

Distribution and Taxonomic Significance of Secondary Metabolites Occurring in the Methanol Extracts of the Stonecrops (Sedum L., Crassulaceae) from the Central Balkan Peninsula

The present study is engaged in the chemical composition of methanol extracts of Sedum taxa from the central part of the Balkan Peninsula, and representatives from other genera of Crassulaceae ( Crassula, Echeveria and Kalanchoe) considered as out-groups. The chemical composition of extracts was determined by HPLC analysis, according to retention time of standards and characteristic absorption spectra of components. Identified components were considered as original variables with possible chemotaxonomic significance. Relationships of examined plant samples were investigated by agglomerative hierarchical cluster analysis (AHC). The obtained results showed how the distribution of methanol extract components (mostly phenolics) affected grouping of the examined samples. The obtained clustering showed satisfactory grouping of the examined samples, among which some representatives of the Sedum series, Rupestria and Magellensia, are the most remote. The out-group samples were not clearly singled out with regard to Sedum samples as expected; this especially applies to samples of Crassula ovata and Echeveria lilacina, while Kalanchoe daigremontiana was more separated from most of the Sedum samples.

Distribution and variability of n-alkanes in epicuticular waxes of sedum species from the central Balkan Peninsula: chemotaxonomic importance

For the first time, the n-alkane distribution and variability of the epicuticular waxes within 22 Sedum taxa was reported with focus on the chemotaxonomy of native Sedum representatives from the central Balkan Peninsula, compared to their relations with four other species of the Crassulaceae family. By GC/MS and GC-FID identification and quantification, it was established that n-alkanes C27 , C29 , C31 , C33 , and C35 were the dominant constituents of the examined epicuticular wax samples. Applying multivariate statistical analyses including agglomerative hierarchical clustering (AHC) and principal component analysis (PCA), the relation according to the n-alkane composition between the examined samples was established. It was shown that the n-alkane variability of the central Balkan Sedum species was considerable and that n-alkanes might not be very reliable taxonomic markers for these species.

Compounds from Sedum caeruleum with antioxidant, anticholinesterase, and antibacterial activities

CONTEXT

This is the first study on the phytochemistry, antioxidant, anticholinesterase, and antibacterial activities of Sedum caeruleum L. (Crassulaceae).

OBJECTIVE

The objective of this study is to isolate the secondary metabolites and determine the antioxidant, anticholinesterase, and antibacterial activities of S. caeruleum.

MATERIALS AND METHODS

Six compounds (1-6) were isolated from the extracts of S. caeruleum and elucidated using UV, 1D-, 2D-NMR, and MS techniques. Antioxidant activity was investigated using DPPH(•), CUPRAC, and ferrous-ions chelating assays. Anticholinesterase activity was determined against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes using the Ellman method. Antibacterial activity was performed according to disc diffusion and minimum inhibitory concentration (MIC) methods.

RESULTS

Isolated compounds were elucidated as ursolic acid (1), daucosterol (2), β-sitosterol-3-O-β-D-galactopyranoside (3), apigenin (4), apigetrin (5), and apiin (6). The butanol extract exhibited highest antioxidant activity in all tests (IC50 value: 28.35 ± 1.22 µg/mL in DPPH assay, IC50 value: 40.83 ± 2.24 µg/L in metal chelating activity, and IC50 value: 23.52 ± 0.44 µg/L in CUPRAC), and the highest BChE inhibitory activity (IC50 value: 36.89 ± 0.15 µg/L). Moreover, the chloroform extract mildly inhibited (MIC value: 80 µg/mL) the growth of all the tested bacterial strains.

DISCUSSION AND CONCLUSION

Ursolic acid (1), daucosterol (2), β-sitosterol-3-O-β-D-galactopyranoside (3), apigenin (4), apigetrin (5), and apiin (6) were isolated from Sedum caeruleum for the first time. In addition, a correlation was observed between antioxidant and anticholinesterase activities of bioactive ingredients of this plant.

Chemical constituents from Sedum aizoon and their hemostatic activity

CONTEXT

Sedum aizoon L. (Crassulaceae) (SA) is widely used to treat various hemorrhages in folk medicine. However, its hemostatic constituents are not yet clear.

OBJECTIVE

The chemical constituents of EtOAc fraction from SA and their hemostatic activity were investigated to provide a basis for the application in folk use.

MATERIALS AND METHODS

The chemical constituents were isolated from the aerial parts of SA by column chromatography and identified by IR, MS, and NMR, then tested for hemostatic activity using the capillary method and coagulation assays including blood clotting time in vivo, and prothrombin time (PT), activated partial thromboplastin time (APTT), and thrombin time (TT) in vitro at concentrations of 300.0, 100.0, and 30.0 µg/mL.

RESULTS

Eleven compounds were identified as p-hydroxybenzoic acid (1), gallic acid (2), protocatechuic acid (3), vallinic acid (4), thymine (5), caffeic acid (6), 5,7-dihydroxy chromone (7), pyrogallol (8), quercetin (9), kaempferol (10), and luteolin (11). This is the first report of compounds 3-8 being isolated from this plant. Compounds 2 (300.0 and 100.0 µg/mL), 4 (100.0 µg/mL), and 11 (100.0 and 30.0 µg/mL) significantly reduced the clotting time (p < 0.01) with inhibition rates of 34.7, 24.5, 30.3, 25.9, and 36.6%, respectively. For further mechanism study, they also reduced PT (3.5, 2.5, 3.5, 3.5, and 3.8%, respectively), APTT (4.5, 3.3, 11.4, 8.5, and 11.1%, respectively), and TT (20.3, 3.8, 7.6, 6.1, and 10.3%, respectively).

DISCUSSION AND CONCLUSION

SA produced hemostatic activity possibly related to the presence of gallic acid, vallinic acid, and luteolin, which may be potent candidates of hemostatic drug.

Chemical compositions by using LC-MS/MS and GC-MS and biological activities of Sedum sediforme (Jacq.) Pau

In this research, the chemical composition and biological activities of various extracts obtained from whole parts of Sedum sediforme (Jacq.) Pau were compared. The amounts of total phenolic and flavonoid components in crude extracts were determined by expression as pyrocatechol and quercetin equivalents, respectively. All of the extracts (petroleum ether, acetone, methanol, and water) obtained from S. sediforme showed strong antioxidant activity in four tested methods. Particularly, the IC50 values of the methanol extract, which was the richest in terms of total phenolic and flavonoid contents, were found to be lower than those of α-tocopherol and BHT in β-carotene bleaching (9.78 ± 0.06 μg/mL), DPPH free radical scavenging (9.07 ± 0.07 μg/mL), and ABTS cation radical scavenging (5.87 ± 0.03 μg/mL) methods. Furthermore, the methanol extract of S. sediforme showed higher inhibition activity than galanthamine against acetyl- and butyryl-cholinesterase enzymes. Also, acetone and methanol extracts exhibited moderate antimicrobial activity against Candida albicans. The main constituents of fatty acid and essential oil were identified as palmitic acid (C16:0) (28.8%) and α-selinene (20.4%), respectively, by GC-MS. In the methanol extract of S. sediforme, quercetin, rutin, naringenin, and protocatechuic, p-coumaric, caffeic, and chlorogenic acids were detected and quantified by LC-MS/MS. Results of the current study showed that the methanol extract of S. sediforme may also be used as a food supplement.

Effect of Gallotannins Derived from Sedum takesimense on Tomato Bacterial Wilt

In the process of searching antibacterial agents from plants, we discovered that the methanol extract of Sedum takesimense showed potent antibacterial activity against Ralstonia solanacearum in vitro and in vivo. Eight antibacterial gallotannins were isolated from the aerial parts of S. takesimense and identified as gallic acid, methyl gallate, 4,6-di-O-galloylarbutin, 2,6-di-O-galloylarbutin, 2,4,6-tri-O-galloyl-glucose, 1,3,4,6-tetra-O-galloyl-β-glucose, 1,2,4,6-tetra-O-galloyl-β-glucose, and 1,2,3,6-tetra-O-galloyl-β-glucose based on electrospray ionization mass spectrometry and proton nuclear magnetic resonance spectroscopy. These gallotannins displayed broad-spectrum activity against various plant-pathogenic bacteria, and the strongest in vitro antibacterial activities of these gallotannins were against R. solanacearum minimum inhibitory concentration = 0.02 to 0.10 g/liter). Among these gallotannins, methyl gallate and 1,2,3,6-tetra-O-galloyl-β-glucose showed the strongest activities. In addition, synergistic or partial synergistic effects were observed in most combinations between major antibacterial compounds. The wettable powder formulation of the S. takesimense crude extract effectively reduced the development of tomato bacterial wilt caused by R. solanacearum under greenhouse conditions for 14 days after infection. This is the first report on the isolation of antibacterial compounds from S. takesimense. These results suggest that the extract from S. takesimense or the isolated gallotannins could be used as natural bactericides for the control of tomato bacterial wilt.

Cytotoxicity and pharmacogenomics of medicinal plants from traditional korean medicine

Aim. The present study was designed to investigate the cytotoxicity of a panel of 280 Korean medicinal plants belonging to 73 families and 198 species against human CCRF-CEM leukemia cells. Selected phytochemicals were investigated in more detail for their mode of action. Methods. The resazurin assay was used to determine cytotoxicity of the plant extracts. Microarray-based mRNA expression profiling, COMPARE, and hierarchical cluster analyses were applied to identify which genes correlate with sensitivity or resistance to selected phytochemicals of the Korean plants. Results. The results of the resazurin assay showed that cytotoxicity extracts tested at 10  μ g/mL from 13 samples inhibited proliferation more than 50% (IC50 < 10  μ g/mL) and the most active plants are Sedum middendorffianum (15.33%) and Lycoris radiata (17.61%). Out of 13 selected phytochemicals from these plants, hopeaphenol and deoxynarciclasine were the most cytotoxic ones. Genes from various functional groups (transcriptional or translational regulation, signal transduction, cellular proliferation, intracellular trafficking, RNA metabolism, endoplasmic/sarcoplasmic reticulum function, etc.) were significantly correlated with response of tumor cell lines to these two compounds. Conclusion. The results provide evidence on the possible use of selected Korean medicinal plants and chemical constituents derived from them for the treatment of tumors.

Chemical Compositions of Essential Oils from and

The chemical compositions of essential oils obtained by hydrodistillation from leaves and stems of Xyloselinum vietnamense and X. leonidii,two new species belonging to the family Apiaceae, were analyzed by GC-MS. The major components in both species were sabinene, α- and β-pinene, myrcene, β-phellandrene, ( Z)-β-ocimene, and terpinen-4-ol. The monoterpene sabinene was most abundant in the leaves of X vietnamense(75.0%). These compounds might be considered as chemotaxonomic markers of Xyloselinum species. In the DPPH radical scavenging assay, all four essential oils showed moderate activity, while the water extracts exhibited stronger effects. The strong DPPH scavenging activity of the water residues of X. vietnamens and X. leonidii might be due to their phenolic components. This paper is the first report on the chemical compositions and antioxidant activity of X vietnamens and X. leonidii.

A new prenylated aurone from Artocarpus altilis

Phytochemical study of the methanol extract of Artocarpus altilis resulted in the isolation of a new prenylated aurone, artocarpaurone (1), together with eight known compounds including two prenylated chalcones (2 and 3), three prenylated flavanones (4-6), and three triterpenes (7-9). The structure of 1 was elucidated as 6-hydroxy-2-[8-hydroxy-2-methyl-2-(4-methyl-3-pentenyl)-2H-1-benzopyran-5-ylmethylene]-3(2H)-benzofuranone by spectroscopic methods including 1D and 2D NMR spectra and FT-ICR-MS. Compound 1 showed moderate nitric oxide radical scavenging activity, whereas 2 and 3 had moderate 2,2-diphenyl-1-picrylhydrazyl radical scavenging effect, compared with the positive control (+)-catechin.

Antioxidant and lipoxygenase inhibitory activity of oligostilbenes from the leaf and stem of Vitis amurensis

ETHNOPHARMACOLOGICAL RELEVANCE

The root and stem of Vitis amurensis (Vitaceae) have popularly used as traditional medicine for treatment of cancer and various pains in Korea and Japan. Recent studies, its root and stem possess anti-inflammatory, anti-tumor activities, and protective effects against beta-amyloid-induced oxidative stress.

AIM OF THE STUDY

This study deals with the isolation, structural identification of the potent bioactive compounds from the leaf and stem, and their antioxidant capacity, as well as anti-inflammatory effect via lipoxygenase inhibitory assay.

MATERIALS AND METHODS

All isolated compounds yielded after using column chromatography were identified base on the physico-chemical properties and 1D, 2D NMR spectra. The scavenge ability against DPPH and ABTS(+) radicals, and to inhibit lipid peroxidation, as well as lipoxygenase type I inhibitory activity of all isolates were performed using in vitro assays.

RESULTS

Eleven resveratrol derivatives (1-11), including a new oligostilbene cis-amurensin B (9), whose structures were determined on the basis of extensively spectral analyses, were isolated from the leaf and stem of Vitis amurensis. The isolates (1-11) were examined for their antioxidant activities by evaluating scavenge ability against DPPH and ABTS(+) radicals, and to inhibit lipid peroxidation. Stilbenes 1 and 4, and oligostilbenes 5-10 displayed moderate anti-lipid peroxidation activities, but all the isolates exhibited strong ABTS(+) radical scavenging activity in the dose-dependent manner. In addition, the isolates showed stronger inhibitory capacity against soybean lipoxygenase type I than that of baicalein, a positive control. Of the isolates, r-2-viniferin (8) exhibited the strongest scavenging activity against ABTS(+) radical with TEAC value of 5.57, and the most potential inhibitory effect on soybean lipoxygenase with the IC(50) value of 6.39 microM.

CONCLUSION

This is the first report on the potential antioxidant and LOX-1 inhibitory effects of oligostilbenes isolated from the leaf and stem of Vitis amurensis. In addition, chemical compositions isolated from the leaf and stem are almost similar to those isolated from the root of Vitis amurensis. Therefore, the results may explain, in part, the uses of the leaf and stem, as well as the root of Vitis amurensis in the Korean traditional medicine.

Synthesized different derivatives of low molecular fucoidan extracted from Laminaria japonica and their potential antioxidant activity in vitro

Six low molecular fucoidan (DFPS) derivatives were synthesized successfully, and their potential antioxidant activities were investigated employing various established in vitro systems. All DFPS derivatives possessed considerable antioxidant activity, and had stronger antioxidant ability than DFPS in certain tests. The benzoylated DFPS (PHDF) showed strongest scavenging activity on superoxide, hydroxyl and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, however, DFPS exhibited greatest reducing power. Available data suggested that substituted groups of DFPS played an important role on antioxidant activity, and the mechanism on influence the antioxidant activity of samples of substituted group was indicated.

HIV-1 ribonuclease H inhibitory phenolic glycosides from Eugenia hyemalis

Three new galloyl arbutins, hyemalosides A-C (1-3), along with nine known compounds were isolated from the evergreen tree Eugenia hyemalis. The structures of compounds 1-3 were determined by analysis of NMR and MS data. Compounds 1-3 inhibited HIV-1 RNase H in vitro with IC50 values of 1.46, >18, and 1.19 microM, respectively. However, in a XTT-based cell viability assay using the human T-cell line CEM-SS infected with HIV-1 RT, none of the compounds inhibited the cytopathic effect of HIV-1 infection at the highest dose tested (20 microg/mL).