Phenylethanoid glycosides from Michelia champaca leaves.

Chemical investigation on the leaves of Michelia champaca L. (Magnoliaceae) led to the isolation of five previously undescribed phenylethanoid glycosides (PhGs), 4-O-ß-d-glucopyranosyl-acteoside (1), 4"'-O-(6-O-E-caffeoyl)-ß-d-glucopyranosyl-acteoside (2), 4"'-O-(6-O-E-caffeoyl)-ß-d-glucopyranosyl-isoacteoside (3), 6""-O-E-feruloyl-echinacoside (4), and 6""-O-p-E-coumaroyl-echinacoside (5), together with eighteen known PhGs. Their structures were determined by spectroscopic and chemical methods. All the known PhGs except acteoside (8) were not previously reported in the genus. Twenty-one PhGs exhibited more potent DPPH radical scavenging activity and FRAP than l-ascorbic acid (l-AA), and twenty-two PhGs showed better ABTS radical cation scavenging activity than l-AA. In addition, twelve PhGs displayed more potent cellular reactive oxygen species (ROS) scavenging activity than curcumin. The results revealed that the leaves of M. champaca are a rich source of phenylethanoid glycosides and antioxidants.

Anti-inflammatory activity of verbascoside- and isoverbascoside-rich Lamiales medicinal plants.

Verbascoside and isoverbascoside are two active phenylethanoid glycosides mainly found in plants of the order Lamiales. This study analyzes the verbascoside and isoverbascoside levels and the total phenolic contents in the water and ethanolic extracts of 20 medicinal plants of the order Lamiales commonly used in Thailand. The related bioactivities, including the antioxidant activity via the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reduction activity potential assays and anti-tyrosinase and -inflammatory activities via the cyclooxygenase and nitric oxide assays are also investigated. The extracts of several plant species, including Barleria prionitis, B. lupulina, Rhinacanthus nasutus, Orthosiphon aristatus, and Nicoteba betonica, exhibit high verbascoside and isoverbascoside content levels. The correlation analysis between the bioactive activities and the active compounds demonstrates a significant association between the verbascoside level in the water extracts and both the DPPH antioxidant activity and the nitric oxide level in the anti-inflammatory assays. This study provides the first report on the verbascoside and isoverbascoside quantification of several plant samples. The findings provide valuable insights for future research on lesser-studied plants possessing high verbascoside and isoverbascoside levels, which exhibit promising anti-inflammatory activities.

Molecular Identification of UDP-Sugar-Dependent Glycosyltransferase and Acyltransferase Involved in the Phenylethanoid Glycoside Biosynthesis Induced by Methyl Jasmonate in Sesamum indicum L.

Sesame (Sesamum indicum L.) plants contain large amounts of acteoside, a typical phenylethanoid glycoside (PhG) that exhibits various pharmacological activities. Although there is increasing interest in the biosynthesis of PhGs for improved production, the pathway remains to be clarified. In this study, we established sesame-cultured cells and performed transcriptome analysis of methyl jasmonate (MeJA)-treated cultured cells to identify enzyme genes responsible for glucosylation and acylation in acteoside biosynthesis. Among the genes annotated as UDP-sugar-dependent glycosyltransferase (UGT) and acyltransferase (AT), 34 genes and one gene, respectively, were upregulated by MeJA in accordance with acteoside accumulation. Based on a phylogenetic analysis, five UGT genes (SiUGT1-5) and one AT gene (SiAT1) were selected as candidate genes involved in acteoside biosynthesis. Additionally, two AT genes (SiAT2-3) were selected based on sequence identity. Enzyme assays using recombinant SiUGT proteins revealed that SiUGT1, namely, UGT85AF10, had the highest glucosyltransferase activity among the five candidates against hydroxytyrosol to produce hydroxytyrosol 1-O-glucoside. SiUGT1 also exhibited glucosyltransferase activity against tyrosol to produce salidroside (tyrosol 1-O-glucoside). SiUGT2, namely, UGT85AF11, had similar activity against hydroxytyrosol and tyrosol. Enzyme assay using the recombinant SiATs indicated that SiAT1 and SiAT2 had activity transferring the caffeoyl group to hydroxytyrosol 1-O-glucoside and salidroside (tyrosol 1-O-glucoside) but not to decaffeoyl-acteoside. The caffeoyl group was attached mainly at the 4-position of glucose of hydroxytyrosol 1-O-glucoside, followed by attachment at the 6-position and the 3-position of glucose. Based on our results, we propose an acteoside biosynthetic pathway induced by MeJA treatment in sesame.

Combined Metabolome and Transcriptome Analysis Highlights the Host's Influence on Cistanche deserticola Metabolite Accumulation.

The medicinal plant Cistanche deserticola Ma (Orobanchaceae) is a holoparasitic angiosperm that takes life-essential materials from Haloxylon ammodendron (C. A. Mey.) Bunge (Amaranthaceae) roots. Although many experiments have been conducted to improve the quality of C. deserticola, little attention has been paid to the host's influence on metabolite accumulation. In this study, transcriptomic and metabolomic analyses were performed to unveil the host's role in C. deserticola's metabolite accumulation, especially of phenylethanoid glycosides (PhGs). The results indicate that parasitism by C. deserticola causes significant changes in H. ammodendron roots in relation to metabolites and genes linked to phenylalanine metabolism, tryptophan metabolism and phenylpropanoid biosynthesis pathways, which provide precursors for PhGs. Correlation analysis of genes and metabolites further confirms that C. deserticola's parasitism affects PhG biosynthesis in H. ammodendron roots. Then we found specific upregulation of glycosyltransferases in haustoria which connect the parasites and hosts. It was shown that C. deserticola absorbs PhG precursors from the host and that glycosylation takes place in the haustorium. We mainly discuss how the host resists C. deserticola parasitism and how this medicinal parasite exploits its unfavorable position and takes advantage of host-derived metabolites. Our study highlights that the status of the host plant affects not only the production but also the quality of Cistanches Herba, which provides a practical direction for medicinal plant cultivation.

Hepatoprotective Principles from the Rhizomes of Picrorhiza kurroa.

A methanol extract of rhizomes of Picrorhiza kurroa Royle ex Benth. (Plantaginaceae) showed hepatoprotective effects against D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced liver injury in mice. We had previously isolated 46 compounds, including several types of iridoid glycosides, phenylethanoid glycosides, and aromatics, etc., from the extract. Among them, picroside II, androsin, and 4-hydroxy-3-methoxyacetophenone exhibited active hepatoprotective effects at doses of 50-100 mg/kg, per os (p.o.) To characterize the mechanisms of action of these isolates and to clarify the structural requirements of phenylethanoid glycosides for their hepatoprotective effects, their effects were assessed in in vitro studies on (i) D-GalN-induced cytotoxicity in mouse primary hepatocytes, (ii) LPS-induced nitric oxide (NO) production in mouse peritoneal macrophages, and (iii) tumor necrosis factor-α (TNF-α)-induced cytotoxicity in L929 cells. These isolates decreased the cytotoxicity caused by D-GalN without inhibiting LPS-induced macrophage activation and also reduced the sensitivity of hepatocytes to TNF-α. In addition, the structural requirements of phenylethanoids for the protective effects of D-GalN-induced cytotoxicity in mouse primary hepatocytes were evaluated.

Scutellaria incarnata Vent. root extract and isolated phenylethanoid glycosides are neuroprotective against C2-ceramide toxicity.

ETHNOPHARMACOLOGICAL RELEVANCE: Neuronal death is a central process in neurodegenerative diseases and represents a therapeutic challenge for their prevention and treatment. Scutellaria incarnata Vent. roots are used traditionally in Colombia for central nervous system conditions including those affecting cognitive functions, but their chemistry and neuroprotective action remain to be explored to understand the scientific basis for their medicinal uses. In this study, S. incarnata roots are investigated to assess whether they have neuroprotective effects that could provide some explanation for their traditional use in neurodegenerative diseases. AIM OF THE STUDY: To evaluate the neuroprotective effect of S. incarnata roots and its chemical constituents against C2-ceramide-induced cell death in Cath.-a-differentiated (CAD) cells. MATERIALS AND METHODS: S. incarnata root ethanol extract was fractionated and compounds were isolated by column chromatography; their structures were elucidated by nuclear magnetic resonance spectroscopy, mass spectrometry and infrared spectroscopy. The cytotoxic and neuroprotective effects against C2-ceramide of S. incarnata root extract, fractions and isolated compounds were assessed in CAD cells. RESULTS: S. incarnata root extract and its n-butanol fraction were not cytotoxic but showed neuroprotective effects against C2-ceramide toxicity in CAD cells. The phenylethanoid glycosides incarnatoside (isolated for the first time) and stachysoside C (12.5, 25 and 50 µg/mL) from S. incarnata roots also protected CAD cells against C2-ceramide without inducing cytotoxic effects. CONCLUSION: The observed neuroprotective effects of S. incarnata root extract and isolated phenylethanoid glycosides in CAD cells provide an ethnopharmacological basis for the traditional use of this species in Colombia for central nervous system disorders.

Inhibition of α-Glycosidase by Lippia dulcis Trevir. (Verbenaceae) Preparations, Quantification of Verbascoside, and Study of Its Molecular Docking.

This study aimed to quantify verbascoside (VEB), perform molecular docking studies of VEB with the α-glucosidase (GL) of Bacillus stearothermophilus, and evaluate the inhibition of the enzyme by L. dulcis preparations. The substrate concentration and presence of reduced glutathione were evaluated for their effect on the in vitro inhibition of the GL enzyme. Assays were also performed in the presence and absence of simulated gastric fluid. The antidiabetic fractions 2 and 3 were the most inhibited GL, but their activity were significantly decreased in the presence of gastric fluid. Chromatographic analyses confirmed the predominant presence of VEB in the samples. The samples had VEB concentrations between 49.9 and 243.5 mg/g. Simulation of the molecular docking of VEB were consistent with its GL-inhibitory activity. It can conclude that the crude ethanol extract and fractions show inhibitory activity against the GL enzyme.

New lignans and phenylethanoid with antioxidant activity from aerial parts of Forsythia suspensa (Thunb.) Vahl.

Two new lignans, phillyroside A(1) and phillyroside B(2), together with three new phenylethanoid glycoside, forsythoside K(3), forsythoside L(5) and forsythol L (4), while compounds 4 was an aglycon of forsythoside L(5), were isolated from the aerial parts of Forsythia suspensa (Thunb.) Vahl. Their structures were elucidated by comprehensive analyses of standard spectroscopic data (MS, IR, and NMR) and the in vitro antioxidant activity of five new compounds were evaluated in DPPH and ABTS radical scavenging experiment and ferric reducing ability of plasma (FRAP) experiment. Compounds 4 and 5 exhibited antioxidant activity with IC50 values ranging from 112.49 to 153.58 µM in DPPH experiment and 45.43 to 64.09 µM in ABTS experiment.

Phenylethanoid and Phenylmethanoid Glycosides from the Leaves of Ligustrum robustum and Their Bioactivities.

The phytochemical study on the leaves of Ligustrum robustum, which have been used as Ku-Ding-Cha, led to the isolation and identification of three new phenylethanoid glycosides and three new phenylmethanoid glycosides, named ligurobustosides R1 (1b), R2-3 (2), R4 (3), S1 (4b), S2 (5), and S3 (6), and five reported phenylethanoid glycosides (7-11). In the bioactivity test, (Z)-osmanthuside B6 (11) displayed strong fatty acid synthase (FAS) inhibitory activity (IC50: 4.55 ± 0.35 µM) as the positive control orlistat (IC50: 4.46 ± 0.13 µM), while ligurobustosides R4 (3) and S2 (5), ligupurpuroside B (7), cis-ligupurpuroside B (8), ligurobustoside N (9), osmanthuside D (10), and (Z)-osmanthuside B6 (11) showed stronger ABTS radical scavenging activity (IC50: 2.68 ± 0.05~4.86 ± 0.06 µM) than the positive control L-(+)-ascorbic acid (IC50: 10.06 ± 0.19 µM). This research provided a theoretical basis for the leaves of L. robustum as a tea with function in treating obesity and diabetes.

[One new phenylethanoid glycoside from Forsythiae Fructus].

One new phenylethanoid glycoside was isolated from the ethyl acetate fraction of the 75% EtOH extract of Forsythiae Fructus by various column chromatographies(HP20, silica gel, ODS) and preparative HPLC.Its structure was identified as forsythiayanoside E(1) by physicochemical properties and extensive spectroscopic analysis(HR-ESI-MS, 1 D and 2 D NMR).Compound 1 was evaluated for cytotoxic activities by MTT assay and showed weak cytotoxic activity against MCF-7 and A-375 cell lines with inhibition rates of 39.85% and 43.38% at 40 µmol·L~(-1), and no cytotoxic activity against PC-3 and HepG2 cell lines at 100 µmol·L~(-1).

Anti-inflammatory effects of flavonoids and phenylethanoid glycosides from Hosta plantaginea flowers in LPS-stimulated RAW 264.7 macrophages through inhibition of the NF-κB signaling pathway.

BACKGROUND: The flower of Hosta plantaginea (Lam.) Aschers has traditionally been used in China as an important Mongolian medicine for the treatment of inflammatory diseases with limited scientific evidence. In previous studies, 16 flavonoids and 3 phenylethanoid glycosides (1-19) were isolated from the ethanolic extract of H. plantaginea flowers. Nevertheless, the anti-inflammatory effects of these constituents remain unclear. In the present study, the anti-inflammatory effects of these 19 constituents and their underlying mechanisms were assessed in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. METHODS: The viability of RAW 264.7 macrophages was detected by Cell Counting Kit-8 (CCK-8) assay. Meanwhile, nitric oxide (NO) production was measured by Griess assay, while the secretion of tumor necrosis factor α (TNF-α), prostaglandin E2 (PGE2), interleukin 1ß (IL-1ß) and IL-6 in LPS-induced macrophages was determined by enzyme-linked immunosorbent assay (ELISA). Furthermore, the protein expression of nuclear factor kappa B (NF-κB) p65 and phosphorylated NF-κB p65 was evaluated by Western blot analysis. RESULTS: All constituents effectively suppressed excessive NO production at a concentration of 40 µM with no toxicity to LPS-induced RAW 264.7 macrophages. Among them, five flavonoids (1, 4-6 and 15) and one phenylethanoid glycoside (17) remarkably prevented the overproduction of NO with median inhibitory concentration (IC50) values in the range of 12.20-19.91 µM. Moreover, compounds 1, 4-6, 15 and 17 potently inhibited the secretion of TNF-α, PGE2, IL-1ß and IL-6, and had a prominent inhibitory effect on the down-regulation of the phosphorylated protein level of NF-κB p65. CONCLUSION: Taken together, compounds 1, 4-6, 15 and 17 may be useful in managing inflammatory diseases by blocking the NF-κB signaling pathway and suppressing the overproduction of inflammatory mediators.

Changes in phenolic compounds production as a defensive mechanism against hydrogen sulfide pollution in Scrophularia striata.

Increasing pollutants such as hydrogen sulfide (H2S) from industrial activities is an ecological challenge for plants, which seriously affects their health and productivity. Scrophularia striata is a plant endemic to Iran growing in the province of Ilam, wherein a gas refinery releases toxic agents such as H2S whose detrimental effects on the function and tolerability of medicinal plants in this region have yet to be elucidated. Thus, we initiated a hydroponic study into hormetic effect of sodium hydrogen sulfide (NaHS) concentrations (0, 3 and 7 mM) as H2S-donor at different time points on oxidative status and phenolic compounds, focusing more on phenylethanoid glycosides (PhGs) in S. striata. Our results indicated that hydrogen peroxide (H2O2) increased significantly at 3 mM NaHS after 48 h, while its peak at 7 mM occurred after 24 h. Nitric oxide (NO) level peaked at 3 mM and 7 mM after 24 h. Treatment with NaHS also resulted in a dose-dependent induction of phenylalanine ammonia-lyase (PAL) and tyrosine ammonia-lyase (TAL) enzyme activities, phenolic acids production (cinnamic acid, coumaric acid, ferulic acid, caffeic acid and salicylic acid) and acteoside accumulation, ultimately leading to an increase in antioxidant capacity. Modulation of soluble sugars contents including glucose, mannose and rhamnose/xylose, occurred after the treatment with NaHS, likely increasing plant tolerance due to their biological activity and structural effects. Overall, our results suggest that dose-dependent accumulation of phenolics, notably acteoside, leads to an augmentation in antioxidant system to deal with H2S stress in S. striata.

Research Progress and Trends of Phenylethanoid Glycoside Delivery Systems.

BACKGROUND: Phenylethanoid glycosides (PhGs) are obtained from a wide range of sources and show strong biological and pharmacological activities, such as antioxidant, antibacterial and neuroprotective effects. However, intestinal malabsorption and the low bioavailability of PhGs seriously affect their application. Delivery systems are an effective method to improve the bioavailability of active substances. Scope and approach: In this article, the biological activities of and delivery systems for PhGs are introduced. The application statuses of delivery systems for echinacoside, acteoside and salidroside are reviewed. Finally, the problems of the lack of uniform standards for delivery systems and the poor targeted delivery accuracy of PhGs in the current research are proposed and suggestions for future research are put forward based on those problems. KEY FINDINGS AND CONCLUSIONS: Although there are still some problems in the delivery system of phenylethanoside, such as inconsistent standards and inaccurate delivery, phenylethanoside itself has been proven to have a variety of physiological activities. Therefore, the action mechanism and application of phenylethanoside and its delivery system should be studied further.

Analysis of flavonoids and phenylethanoid glycosides in the Tibetan herb Lagotis brevituba Maxim based on UHPLC-LTQ-orbitrap-MS / 药学学报

Ultra high performance liquid chromatography tandem linear ion trap orbitrap mass spectrometry (UHPLC-LTQ-orbitrap-MS) was applied to analyze and identify flavonoids and phenylethanoid glycosides in the Tibetan herb Lagotis brevituba Maxim. A method of data-dependent scan coupling with dynamic exclusion was developed for analyzing flavonoids and phenylethanoid glycosides under positive and negative ion mode of electrospray ionization (ESI). The compounds of Lagotis brevituba Maxim. were systematically identified through exact molecular mass, fragmentation patterns, retention time and reported references. A total of 167 compounds were detected, of which 84 were flavonoids and 83 were phenylethanoid glycosides, which greatly enriched the number and types of flavonoids and phenylethanol glycosides in Lagotis genus medicinal plants. Baohuoside Ⅰ, 4 disaccharide O-glycoside flavonoids (composed of deoxyhexose and glucuronic acid), 9 C-glycoside flavonoids, 15 tetrasaccharide phenylethanoid glycosides and 5 phenylethanoid glycosides with substituents on the β-position of the phenylethyl group were identified in Lagotis genus medicinal plants for the first time. This study provides scientific support for elucidating the material basis and improving the quality control of Lagotis brevituba Maxim.

[A new phenylethanol glycoside from Baphicacanthis Cusiae Rhizoma et Radix].

The 95% ethanol extract of Baphicacanthis Cusiae Rhizoma et Radix was purified by multi-chromatographic methods including microporous resin, silica gel, Sephadex LH-20, and C_(18) reversed-phase column chromatography. Fourteen compounds were isolated and structurally identified, including five phenylethanoid glycosides, five phenylpropanoids, one lupinane triterpene, two alkaloids, and one flavonoid, listed as follows: 2-(4-hydroxy-3-methoxyphenyl)-3-(2-hydroxy-5-methoxyphenyl)-3-oxo-1-propanol B(1), threo-2,3-bis-(4-hydroxy-3-methoxybenzene)-3-methoxypropanol(2), 2-(3-hydroxy-4-methoxyphenyl)-ethanol-1-O-[3,4-O-di-acetyl-(1→3)-O-α-L-rhamnopyranosyl]-ß-D-glucopyranoside(3), verbascoside(4), 2″,3″-di-O-acetyl martynoside(5),(+)-pinore-sinol(6), diospyrosin(7), daidzein(8), wiedemannioside B(9), buddlenol A(10), 2″-O-acetyl martyonside(11), lupeol(12), indirubin(13), and tryptanthrin(14). Compound 3 was a new phenylethanoid glycoside, and the other 10 compounds were isolated for the first time from Baphicacanthis Cusiae Rhizoma et Radix except compounds 12, 13, and 14.

Rapid and comprehensive profiling of α-glucosidase inhibitors in Buddleja Flos by ultrafiltration HPLC-QTOF-MS/MS with diagnostic ions filtering strategy.

Buddleja Flos is used as yellow rice colorant and a well-known traditional Chinese medicine. But its biochemical profiling is still lack due to complex matrix. Here, ultrafiltration high-performance liquid chromatograph-quadrupole time-of-flight tandem mass spectrometry (HPLC-QTOF-MS/MS) with diagnostic ions filtering strategy was proposed for rapid and comprehensive investigation of its α-glucosidase inhibitors. As a result, 33 bioactive compounds (13 phenylethanoid glycosides and 20 flavonoids) were successfully screened and identified. In addition, α-glucosidase inhibitory activities of twenty-two references were verified. Six flavonoid aglycones (4, 28, and 30-33) showed excellent α-glucosidase inhibitory activities (IC50, from 5.11 ± 0.85 to 32.49 ± 9.76 µg/mL), much higher than that of acarbose (IC50, 195.49 ± 10.05 µg/mL). Five flavonoid-monoglycosides (7, 12, 13, 20, and 22) presented moderate inhibitory activities with IC50 from 160.98 ± 23.19 to 249.37 ± 35.83 µg/mL. Results showcased the high efficiency of proposed strategy in profiling of bioactive compounds from natural products.

A new phenylethanol glycoside from Baphicacanthis Cusiae Rhizoma et Radix / 中国中药杂志

The 95% ethanol extract of Baphicacanthis Cusiae Rhizoma et Radix was purified by multi-chromatographic methods including microporous resin, silica gel, Sephadex LH-20, and C_(18) reversed-phase column chromatography. Fourteen compounds were isolated and structurally identified, including five phenylethanoid glycosides, five phenylpropanoids, one lupinane triterpene, two alkaloids, and one flavonoid, listed as follows: 2-(4-hydroxy-3-methoxyphenyl)-3-(2-hydroxy-5-methoxyphenyl)-3-oxo-1-propanol B(1), threo-2,3-bis-(4-hydroxy-3-methoxybenzene)-3-methoxypropanol(2), 2-(3-hydroxy-4-methoxyphenyl)-ethanol-1-O-[3,4-O-di-acetyl-(1→3)-O-α-L-rhamnopyranosyl]-β-D-glucopyranoside(3), verbascoside(4), 2″,3″-di-O-acetyl martynoside(5),(+)-pinore-sinol(6), diospyrosin(7), daidzein(8), wiedemannioside B(9), buddlenol A(10), 2″-O-acetyl martyonside(11), lupeol(12), indirubin(13), and tryptanthrin(14). Compound 3 was a new phenylethanoid glycoside, and the other 10 compounds were isolated for the first time from Baphicacanthis Cusiae Rhizoma et Radix except compounds 12, 13, and 14.

Anti-Zika virus activity and chemical characterization by ultra-high performance liquid chromatography (UPLC-DAD-UV-MS) of ethanol extracts in Tecoma species.

BACKGROUND: Plant species from the genus Tecoma are found in tropical and subtropical regions around the world. Some of them are grown as ornamental plants and others can be used as medicinal plants. In the present study, ethanolic extracts from trunks and leaves of Tecoma species were tested in vitro using assays against the Zika virus. METHODS: There was a total of 8 extracts obtained from different anatomical parts of three Tecoma species. The Tecoma castaneifolia, T. garrocha, T. stans var. angustata and T. stans var. stans were prepared by percolation with ethanol. The antiviral activity was assayed in vitro against the Zika virus by the MTT colorimetric method (n = 3). The UPLC-DAD-MS analysis of ethanolic extracts was performed from all the studied species. The biofractionation of T. stans var. stans trunk extract using different separation techniques led to the isolation of crenatoside compound. RESULTS: Ethanolic extract from Tecoma species leaves were more active against the Zika virus (EC50 149.90 to 61.25 µg/mL) when compared to the trunk extracts tested (EC50 131.0 to 66.79 µg/mL and two were not active). The ethyl acetate and aqueous fractions obtained from T. stans var. stans trunk were active against the Zika virus with EC50 values of 149.90 and 78.98 µg/mL, respectively. Crenatoside is a phenylethanoid glycoside isolated from the ethyl acetate of T. stans var. stans trunk extract. This compound was tested and exhibited EC50 34.78 µM (21.64 µg/mL), thus demonstrating a better result than the original ethanolic extracts as well as others extracts of Tecoma species, and it was more active than the positive control, ribavirin (386.84 µM). Furthermore, its selectivity index was at least 2.5 times higher than the tested ethanolic extracts and 11.1 times more potent than ribavirin. CONCLUSION: The Tecoma species demonstrated interesting in vitro activity against the Zika virus. The crenatoside, phenylethanoid glycoside that was for the first time isolated from Tecoma stans var. stans, exhibited a potent and relevant anti-Zika virus activity, being more active than ribavirin (positive control). The data show that crenatoside, was a promising compound with in vitro antiviral activity against the Zika virus.

Herba Cistanche (Rou Cong Rong): A Review of Its Phytochemistry and Pharmacology.

Herba Cistanche, known as Rou Cong Rong in Chinese, is a very valuable Chinese herbal medicine that has been recorded in the Chinese Pharmacopoeia. Rou Cong Rong has been extensively used in clinical practice in traditional herbal formulations and has also been widely used as a health food supplement for a long time in Asian countries such as China and Japan. There are many bioactive compounds in Rou Cong Rong, the most important of which are phenylethanoid glycosides. This article summarizes the up-to-date information regarding the phytochemistry, pharmacology, processing, toxicity and safety of Rou Cong Rong to reveal its pharmacodynamic basis and potential therapeutic effects, which could be of great value for its use in future research.

A trisaccharide phenylethanoid glycoside from Scrophularia flava Grau with potential anti-type 2 diabetic properties by inhibiting α-glucosidase enzyme and decreasing oxidative stress.

The Scrophularia genus is a rich source of phenylethanoid glycosides, with diverse biological activities including anti-diabetic properties. This study investigated anti-type 2 diabetic potential and active component of Scrophularia flava Grau. A new phenylethanoid glycoside was isolated from aerial parts of the plant and identified as 2-(4-hydroxy-3-methoxyphenyl) ethyl 6-deoxy-3-O-[(2E)-3-(3 hydroxy-4-methoxyphenyl) prop-2-enoyl]-α-rhamnopyranosyl-(1 â†’ 3)-[α-rhamnopyranosyl-(1 â†’ 6)]-4-O-[(2E)-3-(4-hydroxy-3-methoxyphenyl) prop-2-enoyl]-ß-glucopyranoside. It was named flavaioside. The structure of flavaioside was identified based on 1H NMR, 13C NMR, DEPT-HSQC, COSY, HMBC, NOESY and LC-ESI-MS-MS. Total methanol extract, fractions (A-F) and specific main phenylethanoid glycoside (flavaioside), were assessed for inhibitory effects against the α-glucosidase enzyme (in vitro anti-type 2 diabetic assay). The antioxidant activities of methanol extracts, all fractions and isolated flavaioside were identified based on 2, 2'-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging activity, 2, 2'-azino-bis (3-ethylbenzothiazoline)-6-sulphonic acid radical cation (ABTS+) scavenging activity, phosphomolybdenum method, and metal chelating activity. In comparison to the other fractions, the best antioxidant result was observed in fraction E and its main compound, flavaioside, in DPPH (IC50 = 4.26, 2.57 µg/mL) and ABTS+ (EC50 = 55.45, 6.34 µg/mL) scavenging activities. Flavaioside showed significantly stronger activities than α-tocopherol and ascorbic acid in DPPH and ABTS+ assays. Furthermore, flavaioside showed a potent inhibitory activity on the α-glucosidase enzyme which was comparable with the known anti-type 2 diabetic drug, acarbose (91.85%, and 92.87%, respectively). Fraction E and flavaioside showed α-glucosidase inhibitory activities with IC50 values, 65.05 and 6.50 µg/mL. The plant and its isolated flavaioside can possess acceptable anti-type 2 diabetic potential and anti-oxidant activity.