Phytochemical constituents from Salsola tetrandra

Investigation of bioactive components responsible for the antibacterial and anti-biofilm activities of Caroxylon volkensii by LC-QTOF-MS/MS analysis and molecular docking

Caroxylon volkensii is a wild desert plant of the family Amaranthaceae. This study represents the first report of the metabolomic profiling of C. volkensii by liquid chromatography quadrupole-time-of-flight tandem mass spectrometry (LC-QTOF-MS/MS). The dereplication study of its secondary metabolites led to the characterization of 66 known compounds. These compounds include catecholamines, tyramine derivatives, phenolic acids, triterpenoids, flavonoids, and others. A new tyramine derivative, alongside other known compounds, was reported for the first time in the Amaranthaceae family. The new derivative and the first-reported compounds were putatively identified through MS/MS fragmentation data. Given the notorious taxonomical challenges within the genus Salsola, to which C. volkensii previously belonged, our study could offer a valuable insight into its chemical fingerprint and phylogenetic relationship to different Salsola species. The antibacterial potential of C. volkensii methanolic extract (CVM) against Pseudomonas aeruginosa was screened. The minimum inhibitory concentration (MIC) of CVM ranged from 32 to 256 μg mL-1. The anti-quorum sensing potential of CVM resulted in a decrease in the percentage of strong and moderate biofilm-forming isolates from 47.83% to 17.39%. It revealed a concentration-dependent inhibitory activity on violacein formation by Chromobacterium violaceum. Moreover, CVM exhibited an in vivo protective potential against the killing capacity of P. aeruginosa isolates. A molecular docking study revealed that the quorum-sensing inhibitory effect of CVM can be attributed to the binding of tyramine conjugates, ethyl-p-digallate, and isorhamnetin to the transcriptional global activator LasR.

Automated Composition Assessment of Natural Extracts: Untargeted Mass Spectrometry-Based Metabolite Profiling Integrating Semiquantitative Detection

Recent developments in mass spectrometry-based metabolite profiling allow unprecedented qualitative coverage of complex biological extract composition. However, the electrospray ionization used in metabolite profiling generates multiple artifactual signals for a single analyte. This leads to thousands of signals per analysis without satisfactory means of filtering those corresponding to abundant constituents. Generic approaches are therefore needed for the qualitative and quantitative annotation of a broad range of relevant constituents. For this, we used an analytical platform combining liquid chromatography-mass spectrometry (LC-MS) with Charged Aerosol Detection (CAD). We established a generic metabolite profiling for the concomitant recording of qualitative MS data and semiquantitative CAD profiles. The MS features (recorded in high-resolution tandem MS) are grouped and annotated using state-of-the-art tools. To efficiently attribute features to their corresponding extracted and integrated CAD peaks, a custom signal pretreatment and peak-shape comparison workflow is built. This strategy allows us to automatically contextualize features at both major and minor metabolome levels, together with a detailed reporting of their annotation including relevant orthogonal information (taxonomy, retention time). Signals not attributed to CAD peaks are considered minor metabolites. Results are illustrated on an ethanolic extract of Swertia chirayita (Roxb.) H. Karst., a bitter plant of industrial interest, exhibiting the typical complexity of plant extracts as a proof of concept. This generic qualitative and quantitative approach paves the way to automatically assess the composition of single natural extracts of interest or broader collections, thus facilitating new ingredient registrations or natural-extracts-based drug discovery campaigns.

Anti-Inflammatory, Anti-Oxidant, GC-MS Profiling and Molecular Docking Analyses of Non-Polar Extracts from Five Salsola Species

Genus Salsola (family Amaranthaceae) is one of the most prevailing genera in Saudi Arabia. Although several species were reported for their traditional uses, the majority of Salsola species still need to be phytochemically and biologically explored. The current study presents the GC-MS profiling as well as an in vitro investigation of the bioactivities of the n-hexane extracts from the five Salsola species: Salsola arabica, S. cyclophylla, S. imbricata, S. incanescens and S. villosa. Additionally, the compounds identified in the most active extracts were screened for their interaction with the active sites of cyclooxygenase enzyme isoforms (COX-1 and COX-2). GC-MS analysis of the n-hexane extracts from the five species resulted in the identification of 67 constituents. Oleic acid (75.57%), 1-octadecene (14.46%), cinnamaldehyde α-hexyl (57.15%), octacosyl heptafluorobutyrate (25.36%) and hexadecanoic acid methyl ester (26.15%) represent the major constituents in S. arabica, S. cyclophylla, S. imbricata, S. inscanescence and S. villosa, respectively. Results of bioactivity testing highlighted S. villosa as having the highest anti-oxidant activity (IC50 0.99 ± 0.05 mg/mL), which was closely followed by S. cyclophylla (IC50 1.36 ± 0.06 mg/mL) compared to the IC50 of 0.16 ± 0.01 mg/mL recorded by ascorbic acid. S. villosa was further noted for having the strongest COX-2 inhibitory activity (IC50 4.6 ± 0.13 µg/mL) among the tested extracts followed by S. arabica (IC50 13.1 ± 0.37 µg/mL) and S. cyclophylla (IC50 20.1 ± 0.57 µg/mL). On the other hand, S. imbricata extract displayed the most characteristic inhibition activity against COX-1 (IC50 10.2 ± 0.52 µg/mL), which was non-significant from the standard drug celecoxib. Based upon bioactivity results, the phytoconstituents identified in S. villosa and S. imbricata extracts were investigated for their capability to interact with the active sites of both cyclooxygenase enzyme isoforms adopting molecular docking. Results indicated the possibility to incorporate the compounds to active sites of the enzymes where some of them bind with their polar end into the cavity beyond Arg120 and their aliphatic chain oriented to the catalytically important Tyr385 similar to the natural substrate arachidonic acid, indicating that they could be promising candidates for the future development of selective COX inhibitors.

The old world salsola as a source of valuable secondary metabolites endowed with diverse pharmacological activities: a review

Salsola is an important genus in the plant kingdom with diverse traditional, industrial, and environmental applications. Salsola species are widely distributed in temperate regions and represent about 45% of desert plants. They are a rich source of diverse phytochemical classes, such as alkaloids, cardenolides, triterpenoids, coumarins, flavonoids, isoflavonoids, and phenolic acids. Salsola spp. were traditionally used as antihypertensive, anti-inflammatory, and immunostimulants. They attracted great interest from researchers as several pharmacological activities were reported, including analgesic, antipyretic, antioxidant, cytotoxic, hepatoprotective, contraceptive, antidiabetic, neuroprotective, and antimicrobial activities. Genus Salsola is one of the most notorious plant genera from the taxonomical point of view. Our study represents a comprehensive review of the previous phytochemical and biological research on the old world Salsola secies. It is designed to be a guide for future research on different plant species that still belong to this genus or have been transferred to other genera.

Phytochemical Analysis, Anti-inflammatory, and Anticancer Activities of the Halophyte Herb Bassia indica

Bassia indica (Wight) A.J. Scott, family Amaranthaceae, is a halophyte herb growing in extreme environments and hence deemed as a potential economic source of bioactive chemicals with functional properties. In our study, 25 compounds were obtained from B. indica. We aimed to assess the inhibitory effect of the methanol extract of B. indica and its isolated compounds on COX-2 and cytotoxicity activity against MCF-7, OVK-18, HepG2, and HCT116 tumor cells. Among the isolates, the triterpene oleanane saponin (23) displayed promising anti-inflammatory activity with an IC50 = 3.05 ± 0.15 μg/mL. Additionally, N- trans-feruloyl tyramine (11) exhibited significant cytotoxicity to OVK-18 with IC50 = 1.74 ± 1.56 μg/mL, whereas 6,7-dihydroxy coumarin (7) exhibited potent inhibition against the MCF-7 cell line with IC50 = 1.47 ± 0.22 μg/mL. Interestingly, compounds 1 and 25 exhibited remarkable cytotoxicity against HepG2 and HCT116 cells with IC50 < 0.1 μg/mL, while compounds 2, 4, 5, 6, and 9 exerted potent cytotoxicity against HepG2. Finally, B. indica is a potential source of candidate compounds for the development of anti-inflammatory and antitumor therapies.

Genus Salsola: Chemistry, Biological Activities and Future Prospective-A Review

The genus Salsola L. (Russian thistle, Saltwort) includes halophyte plants and is considered one of the largest genera in the family Amaranthaceae. The genus involves annual semi-dwarf to dwarf shrubs and woody tree. The genus Salsola is frequently overlooked, and few people are aware of its significance. The majority of studies focus on pollen morphology and species identification. Salsola has had little research on its phytochemical makeup or biological effects. Therefore, we present this review to cover all aspects of genus Salsola, including taxonomy, distribution, differences in the chemical constituents and representative examples of isolated compounds produced by various species of genus Salsola and in relation to their several reported biological activities for use in folk medicine worldwide.

Halophytes for phytoremediation of hazardous metal(loid)s: A terse review on metal tolerance, bio-indication and hyperaccumulation

Phytoremediation is a cost-effective and environment friendly method for cleaning metal(loid)s from contaminated soils. Species with exceptionally higher shoot metal concentrations (hyperaccumulators) seem ideal for phytoremediation, though some metal tolerant species with 'above normal' values with higher translocation factor (TF) may also serve the purpose. Halophytes not only remove salts and metalloids from soils but may also be cultivated as non-conventional crops. Nurturing halophytes requires precise understanding of their nature and efficient management for sustainable use. Species with low metal concentrations in their edible parts (especially leaves) may be grown as forage and fodder, but those with metal hyperaccumulation could prove fatal due to their serious health hazards. Like other metallophytes, redundant use of the term 'metal hyperaccumulation' among halophytes needs to be revisited for its ambiguity and potential pitfalls. Similarly, understanding of metal tolerance and shoot accumulation nature of halophytes is needed prior to their use. This review is an attempt to compare halophytes with potential of metal bioindication, phytostabilization and hyperaccumulation (as per definition) as well as their 'obligate' and 'facultative' nature for appropriate uses.

Phytochemical Analysis, Pharmacological and Safety Evaluations of Halophytic Plant, Salsola cyclophylla

Salsola cyclophylla, an edible halophyte, is traditionally used for inflammation and pain. To confirm the claimed anti-inflammatory and analgesic properties, a detailed study on respective pharmacological actions was undertaken. The activities are contemplated to arise from its phytoconstituents. The LC-MS analysis of S. cyclophylla 95% aqueous-ethanolic extract revealed the presence of 52 compounds belonging to phenols, flavonoids, coumarins, and aliphatics class. A high concentration of Mn, Fe, and Zn was detected by atomic absorption spectroscopic analysis. The ethyl acetate extract showed the highest flavonoid contents (5.94 ± 0.04 mg/g, Quercetin Equivalents) and Fe2+-chelation (52%) potential with DPPH radicals-quenching IC50 at 1.35 ± 0.16 mg/mL, while the aqueous ethanolic extract exhibited maximum phenolics contents (136.08 ± 0.12 mg/g, gallic acid equivalents) with DPPH scavenging potential at IC50 0.615 ± 0.06 mg/mL. Aqueous ethanolic extract and standard quercetin DPPH radicals scavenging's were equal potent at 10 mg/mL concentrations. The aqueous ethanolic extract showed highest analgesic effect with pain reduction rates 89.86% (p = 0.03), 87.50% (p < 0.01), and 99.66% (p = 0.0004) after 60, 90, and 120 min, respectively. Additionally, aqueous ethanolic extract exhibited the highest anti-inflammation capacity at 41.07% (p < 0.0001), 34.51% (p < 0.0001), and 24.82% (p < 0.0001) after 2, 3, and 6 h of extract's administration, respectively. The phytochemical constituents, significant anti-oxidant potential, remarkable analgesic, and anti-inflammatory bioactivities of extracts supported the traditionally claimed anti-inflammatory and analgesic plant activities.

Bassiamide A, a new alkaloid from xero-halophyte Bassia indica Wight

N-[(3-(3-methyl-1-oxo-butyl)amino)propyl]-3-(3,4-dihydroxyphenyl)prop-2-enamide (7), named 'Bassiamide A', a new alkaloid, together with six known compounds including one lignan (1) and five lignanamides (2-6), were isolated from the aerial parts of Bassia indica Wight. The study also reported an optimal separation of a rare occurring R-isomer lignanamide derivative (6) from a natural origin, in addition to its known corresponding S-isomer (5). Structures of isolated compounds were elucidated based on NMR spectroscopic data, HR-MS, and comparison with known related ones, and they were identified as syringaresinol (1), N-trans-feruloyl-3-methoxytyramine (2), N-trans-feruloyltyramine (3), S-(-)-N-trans-feruloyl normetanephrine (4), S-(-)-N-trans-feruloyl octopamine (5), R-(+)-N-trans-feruloyl octopamine (6). The isolated compounds were evaluated for their anti-acetylcholinesterase activity, and they showed weak inhibitory activity.

Bioactive megastigmane glucosides and monoterpenes from Lyonia ovalifolia

Three new megastigmane glucosides (1-3) and two new monoterpenes (4-5), together with 14 related known compounds (6-19) were isolated from the twigs and leaves of Lyonia ovalifolia. The structures of the new compounds were determined by extensive MS, NMR, CD experiments and chemical methods. Compounds 2, 6, and 18 displayed potent antiviral activity against Coxsackie B3, with IC₅₀ values between 6.4 and 14.6 µM. Additionally, compounds 6, 10, and 11 exhibited noteworthy anti-inflammatory activities, with inhibition rates ranging from 54.55% to 83.33% under the concentration of 10^-5 M.

Two new dammarane-type triterpene saponins from Korean red ginseng and their anti-inflammatory effects

Panax ginseng has been the subject of extensive research on potential medicinal materials. The goal of this study was search the chemical constituents and biological activities of processed Panax ginseng, Korean red ginseng. Our efforts led to the isolation eleven compounds (1-11) including two new compounds 1 and 2 from Korean red ginseng using various chromatographic techniques. Chemical structures of isolated compounds were demonstrated by spectroscopic methods (1D-, 2D-NMR, and HR-ESI-MS). The anti-inflammatory effects of the compounds were investigated by inhibiting IL-6 and TNF-α secretion in LPS-activated RAW264.7 cells. Additionally, the effects of the compounds on the expression of COX-2 and iNOS were examined by Western blotting. Compound 1 significantly reduced the level of proinflammatory cytokines IL-6 and TNF-α secretion in LPS-activated RAW264.7 cells and the expression of COX-2 and iNOS inflammatory enzymes in the cells. These results suggested that compound 1, a new ginsenoside might useful in treatment of inflammation.

Antibacterial activities of chemical constituents from the aerial parts of Hedyotis pilulifera

CONTEXT

Hedyotis pilulifera (Pit.) T.N. Ninh (Rubiaceae) has been used in Vietnamese ethnomedicine; the methanol extract exhibited antibacterial activity in our preliminary screening.

OBJECTIVES

In this study, compounds from H. pilulifera were isolated and their antibacterial activity in vitro was evaluated.

MATERIALS AND METHODS

The aerial parts of H. pilulifera (1.4 kg) were extracted with MeOH, suspended in water and ethyl acetate extract was chromatographed on a silica gel column. The structures of isolated compounds were elucidated by the combination analyses of spectroscopy including 1D-, 2D-NMR, HRMS and in comparison with the reported NMR data in the literature. All isolated compounds were evaluated for inhibitory effect using the microdilution method toward Staphylococcus aureus, Bacillus subtilis and Mycobacterium smegmatis, and MIC values were determined.

RESULTS

Twenty compounds were isolated, including five triterpenoids, two steroids, two aromatic compounds, three fatty acids, one quinone derivative, one lignan glycoside, one ceramide and five glycolipids. Among these, oleanolic acid showed significant antibacterial activity against M. smegmatis with the MIC value of 2.5 μg/mL. Remarkably, rotungenic acid showed strong activity against S. aureus, B. subtilis, M. smegmatis with MIC values of 2.5, 2.5 and 1.25 μg/mL, respectively. Rotundic acid exhibited significant antibacterial activity against B. subtilis with the MIC value of 5 μg/mL. To the best of our knowledge, the antibacterial activity of rotungenic acid, stigmast-4-ene-3,6-dione and (2S,3S,4R,2'R)-2-(2'-hydroxytetracosanoylamino) octadecane-1,3,4-triol was reported for the first time.

CONCLUSIONS

Oleanolic acid, rotungenic acid, and rotundic acid were considered to be useful for developing new antimicrobial therapeutic agents for human.

A New Cardenolide and Other Compounds from Salsola tetragona

One new cardenolide, 3- O-β-D-allopyranosylcoroglaucigenin (salsotetragonin) (1), was isolated from the aerial parts of Salsola tetragona Delile with four known cardenolides (2–5), two known flavonoids (6–7), three known phenolic compounds (8–10) and two known fatty acids (11–12). Their structures were identified by spectroscopic analyses and by comparison of their spectral data with those reported in the literature. Compounds 1–5, 7, 10 and 12 were isolated from the genus Salsola for the first time. This is the first report on cardenolides identified in the Amaranthaceae family.

A New Monoacylglycerol from the Fruiting Bodies of Gymnopilus Spectabilis

Bioassay-guided fractionation and chemical investigation of the MeOH extract of the wild mushroom Gymnopilus spectabilis resulted in the isolation of a new monoacylglycerol, together with five known compounds. The structure of the new compound (2′ S) −1- O-(6,6-dimethoxyhexanol)-glycerol was elucidated on the basis of 1D and 2D NMR (1H and 13C NMR, 1H-1H COSY, HMQC and HMBC) spectroscopic data as well as chemical reactions. The known compounds were identified by comparison of their spectroscopic and physical data with the reported values. The metabolites were evaluated for their anti-proliferative activities against four human tumour cell lines (A549, SK-OV-3, SK-MEL-2 and HCT-15) and for their inhibitory effects on nitric oxide production in lipopolysaccharide (LPS)-activated murine microglial cells.

Rubemamine and Rubescenamine, Two Naturally Occurring N-Cinnamoyl Phenethylamines with Umami-Taste-Modulating Properties

Sensory screening of a series of naturally occurring N-cinnamoyl derivatives of substituted phenethylamines revealed that rubemamine (9, from Chenopodium album) and rubescenamine (10, from Zanthoxylum rubsecens) elicit strong intrinsic umami taste in water at 50 and 10 ppm, respectively. Sensory tests in glutamate- and nucleotide-containing bases showed that the compounds influence the whole flavor profile of savory formulations. Both rubemamine (9) and rubescenamine (10) at 10-100 ppm dose-dependently positively modulated the umami taste of MSG (0.17-0.22%) up to threefold. Among the investigated amides, only rubemamine (9) and rubescenamine (10) are able to directly activate the TAS1R1-TAS1R3 umami taste receptor. Moreover, both compounds also synergistically modulated the activation of TAS1R1-TAS1R3 by MSG. Most remarkably, rubemamine (9) was able to further positively modulate the IMP-enhanced TAS1R1-TAS1R3 response to MSG ∼ 1.8-fold. Finally, armatamide (11), zanthosinamide (13), and dioxamine (14), which lack intrinsic umami taste in vivo and direct receptor response in vitro, also positively modulated receptor activation by MSG about twofold and the IMP-enhanced MSG-induced TAS1R1-TAS1R3 responses approximately by 50%. In sensory experiments, dioxamine (14) at 25 ppm in combination with 0.17% MSG exhibited a sensory equivalent to 0.37% MSG.

The chemistry and biological activities of natural products from Northern African plant families: from Aloaceae to Cupressaceae

Traditional medicinal practices play a key role in health care systems in countries with developing economies.

Chemical constituents of Cyrtomium fortumei (J.) Smith

Five known compounds, 6'-methylglucuronide-5-hydroxy-chromone (1), ethyl α-d-glactopyranoside (2), neoechinulin A (3), 9,12,13-trihydroxyoctadeca-10(E),15(Z)-dienoic acid (4) and phellopterin (5), were isolated from water extract of Cyrtomium fortumei (J.) Smith. Compounds 1-5 were isolated from this genus for the first time, and all the compounds were evaluated in vitro against a panel of human cancer cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Among them, compounds 3 and 4 exhibited significant cytotoxic activities, with IC50 values of 15.2 and 18.3 μg/mL on MGC-803 cells, respectively.

Reports on the distribution of aromatic cyanogenic glycosides in Australian tropical rainforest tree species of the Lauraceae and Sapindaceae

The aromatic cyanogenic glycosides taxiphyllin [(R)-4-hydroxymandelonitrile β-D-glucoside] and prunasin [(R)-mandelonitrile β-D-glucoside] were identified as the main cyanogenic compounds in tissues of Australian endemic tropical rainforest tree taxa in the Lauraceae and Sapindaceae families, respectively. The tyrosine-derived taxiphyllin was the main cyanogenic glycoside in foliage of Beilschmiedia collina. This is the first reported cyanogenic compound from the Lauraceae. In addition, substantial quantitative variation in the capacity for cyanogenesis was detected in leaves from 40 individuals, with taxiphyllin concentrations ranging from 23 to 1263 μg CN g(-1) dry wt. No acyanogenic individuals were detected. Concentrations of taxiphyllin were, on average, 2.2-fold greater in young leaves than in old leaves. Prunasin was the dominant cyanogenic compound in tissues of Mischocarpus grandissimus (leaves) and Mischocarpus exangulatus (leaves and seed capsule). Better known for cyanolipids in seed oils, this is the first time a phenylalanine-derived cyanogenic glycoside has been reported in the Sapindaceae. The concentrations of prunasin varied widely, over an order of magnitude, among individuals and different tissue types in these species, with the higher concentrations found in seed capsules and young leaves.

Comprehensive analysis of Phyteuma orbiculare L., a wild Alpine food plant

Plants which have been traditionally eaten by the alpine population may provide new opportunities for agricultural development in mountain regions. In this context we have investigated the chemical composition of Phyteuma orbiculare (Campanulaceae), a perennial herb whose leaves have been eaten as salad by rural populations in Valais (Switzerland). Extracts of different polarities were subjected to comprehensive metabolite profiling using a dereplication platform combining HPLC-PDA-MS, and offline NMR analysis. Twenty-three compounds, including various phenolic glycosides, a new dimeric phenylpropanoid glucoside, saponins, and fatty acids were identified online, or after targeted isolation. Selected phenolic constituents were quantitatively assessed by HPLC-PDA analysis. In addition, substances relevant for nutrition, such as β-carotene, fatty acids, ascorbic acid and minerals were quantified in leaves and flowers. The antioxidant capacity was determined with an ORAC assay, and total phenolic compounds were quantified. Finally, the phytochemical profile was compared to that of the related species P. spicatum, P. hemisphaericum and P. ovatum.

New antioxidant bibenzyl derivative and isoflavonoid from the Tunisian Salsola tetrandra Folsk

Two new phytochemical compounds, Tetranins A and B, 1-(3,5'-dihydroxy-4'-méthoxyphenyl)-2-phenylethanol 1 and 5,2'-dihydroxy-5'-methoxy-6,7-methylenedioxy-isoflavone 2, were isolated from the EtOAc extract of Salsola tetrandra roots. They exhibited a significant antioxidant effect in 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical and 2,2'-azinobis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assays. Their structures were elucidated by extensive spectroscopic methods including 1-D-((1)H and (13)C) and 2-D-NMR experiments (CHcorr, HMBC, (1)H-(1)H COSY and NOESY) as well as high-resolution ES-MS and they were found to be quite active as antioxidants in the DPPH and ABTS assays.

An oxygenase inhibitor study in Solanum lycopersicum combined with metabolite profiling analysis revealed a potent peroxygenase inactivator

Plant genomes contain a vast number of oxygenase genes, but only very few have been functionally characterized. To devise an alternative method for the detection of novel oxygenase-catalysed reactions the effects of the cytochrome P450 oxygenase inhibitors 1-aminobenzotriazole (ABT) and tetcyclacis (TET) have been examined by metabolite profiling analysis in tomato fruit (Solanum lycopersicum). Treatment with TET resulted in significant increases in the levels of certain flavonoids, whereas ABT strongly inhibited their formation during fruit ripening. Injections of buffered solutions of ABT into tomato fruits led rather to an accumulation of 9,12,13-trihydroxy-10(E)-octadecenoic acid probably due to retarded metabolism of the hydroxylated acid, while TET completely repressed its formation. Peroxygenase, a hydroperoxide-dependent hydroxylase involved in the formation of the trihydroxy fatty acid, is strongly inhibited by TET (IC(50) 2.6 μM) as was demonstrated by studies with the recombinant tomato enzyme expressed in yeast. The data show that ABT and TET affect oxygenases differently in tomato fruit and reveal that these enzymes catalyse distinct reactions in different metabolic pathways, among which C(18)-trihydroxy fatty acid and flavonoid metabolism involve novel oxygenase-catalysed reactions. The method is suitable to identify potential substrates and products of ripening-related, putative oxygenases and can support functional analyses of recombinant enzymes.

Antioxidant and Radical Scavenging Properties of Malva Sylvestris

Antioxidant capacity of the aqueous extract of Malva sylvestris was measured by its ability to scavenge the DPPH and superoxide anion radicals and to induce the formation of a phosphomolybdenum complex. Analysis of the extract, carried out by different chromatographic techniques, led to the isolation of eleven compounds: 4-hydroxybenzoic acid, 4-methoxybenzoic acid, 4-hydroxy-3-methoxybenzoic acid, 4-hydroxycinnamic acid, ferulic acid, methyl 2-hydroxydihydrocinnamate, scopoletin, N-trans-feruloyl tyramine, a sesquiterpene, (3 R,7 E)-3-hydroxy-5,7-megastigmadien-9-one, and (10 E,15 Z)-9,12,13-trihydroxyoctadeca-10,15-dienoic acid. The antioxidant activities of all these compounds are reported.

Structure determination of salisomide and salisoflavan, two new secondary metabolites from Salsola imbricata, by 1D and 2D NMR spectroscopy

Chromatographic analysis of the alcoholic extract from Salsola imbricata yielded two new secondary metabolites, salisomide (1) and salisoflavan (2). Their structures were established with the help of spectroscopic techniques including COSY, HMQC and HMBC NMR experiments.

N-trans-feruloyltyramine as a melanin biosynthesis inhibitor

In this study, we examined the effect of N-trans-feruloyltyramine (FA) on melanogenesis in mouse B16 melanoma cells. Melanogenesis was inhibited by FA in a dose-dependent manner. FA exhibited a greater potency than kojic acid as a standard inhibitor of melanogenesis. Moreover, treatment of B16 melanoma cells with FA was found to cause marked decreases in the expression levels of tyrosinase. FA-induced downregulation of tyrosinase resulted in suppression of melanin biosynthesis in murine B16 melanoma cells.