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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.

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Ten secondary metabolites, including one new monoterpene rhamnoside (1), five terpenoids (2-6), two nucleosides (7-8), and two phenylethanoid glycosides (9-10) were isolated from the roots of Rehmannia glutinosa. Their structures were determined by spectroscopic analysis such as NMR and HR-ESI-MS. In the tyrosinase inhibitory assay, compounds 2, 6 and 8 showed inhibition against tyrosinase. Compounds 1, 4, 5, 6, 9 and 10 are being reported in the genus Rehmannia for the first time. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

[Display omitted] • A set of Rehmannia enzyme-coding genes for salidroside biosynthesis was identified. • In vitro activity revealed these enzymes' function for salidroside biosynthesis. • Heterologous coexpression of these enzyme-encoding genes produced salidroside in vivo. Rehmannia glutinosa produces many phenylethanoid glycoside (PhG) compounds, including salidroside, which not only possesses various biological activities but also is a core precursor of some medicinal PhGs, so it is very important to elucidate the species' salidroside biosynthesis pathway to enhance the production of salidroside and its derivations. Although some plant copper-containing amine oxidases (CuAOs), phenylacetaldehyde reductases (PARs) and UDP-glucose glucosyltransferases (UGTs) are thought to be vital catalytic enzymes involved in the downstream salidroside biosynthesis pathways, to date, none of these proteins or the associated genes in R. glutinosa have been characterized. To verify a postulated R. glutinosa salidroside biosynthetic pathway starting from tyrosine, this study identified and characterized a set of R. glutinosa genes encoding RgCuAO, RgPAR and RgUGT enzymes for salidroside biosynthesis. The functional activities of these proteins were tested in vitro by heterologous expression of these genes in Escherichia coli , confirming these catalytic abilities in these corresponding reaction steps of the biosynthetic pathway. Importantly, four enzyme-encoding genes (including the previously reported RgTyDC2 encoding tyrosine decarboxylase and the RgCuAO1 , RgPAR1 and RgUGT2 genes) were cointegrated into Saccharomyces cerevisiae to reconstitute the R. glutinosa salidroside biosynthetic pathway, achieving an engineered strain that produced salidroside and validating these enzymes' catalytic functions. This study elucidates the complete R. glutinosa salidroside biosynthesis pathway from tyrosine metabolism in S. cerevisiae , establishing a basic platform for the efficient production of salidroside and its derivatives. [ABSTRACT FROM AUTHOR]

Chemical investigation on the leaves of Michelia champaca L. (Magnoliaceae) led to the isolation of five previously undescribed phenylethanoid glycosides (PhGs), 4- O - β - d -glucopyranosyl-acteoside (1), 4‴- O -(6- O - E -caffeoyl)- β - d -glucopyranosyl-acteoside (2), 4‴- O -(6- O - E -caffeoyl)- β - 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 scavenging activity than curcumin. The results revealed that the leaves of M. champaca are a rich source of phenylethanoid glycosides and antioxidants. [Display omitted] • Five undescribed phenylethanoid glycosides (PhGs) were isolated from the leaves. • Seventeen known PhGs isolated were not reported from the genus Michelia. • The PhGs showed potent DPPH, ABTS, and cellular ROS scavenging activities. • The results revealed the leaves to be a rich source of PhGs and antioxidants. [ABSTRACT FROM AUTHOR]

Abstract 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 1β (IL-1β) 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-1β 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.

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. [ABSTRACT FROM AUTHOR]

Seven phenolic compounds, including a new phenylethanoid, named passifoside (1), and 6 previously described compounds, syringaresinol (2), berchemol (3), threo -guaiacylglycerol (4), p -hydroxybenzaldehyde (5), 3,4,5-trimethoxyphenyl- O - β -D-glucopyranoside (6), and trans - p -coumaric acid (7), were identified from the aerial parts of Passiflora foetida. Their chemical structures were elucidated from HR-ESI-MS and NMR spectral data, and comparison with the literature. Compound 2 inhibited nitric oxide production in lipopolysaccharide-activated RAW264.7 cells, showing an IC50 value of 9.45 ± 0.33 µM. The other compounds showed either weak or no significant activity compared to L-NMMA, which was used as a positive control. Graphical Abstract This is a visual representation of the abstract. [ABSTRACT FROM AUTHOR]

Fourteen secondary metabolites, including one cinnamate derivative (1), three spirocyclic nortriterpenoids (2-4), three phenylethanoid glycosides (5-7), four lignans (8-11) and three phenolic compounds (12-14) were isolated from the EtOH extract of Leonuri Fructus. Their structures were elucidated on the basis of 1D NMR, 2D NMR and HR-ESI-MS data analysis. All isolates were tested for their antioxidant, tyrosinase and acetylcholinesterase inhibitory activities. Most of them showed moderate antioxidant activities. Compounds 2-4 exhibited obvious inhibitory activities against mushroom tyrosinase at 25 µM, with %inhibition values of 49.36 ±2.69%, 43.43 ± 3.35%, 51.69 ± 2.81%, respectively, with arbutin used as the positive control (51.90 ± 2.57%). Compounds 3, 5-6 and 9-10 exhibited significant inhibitory activities against acetylcholinesterase, similar to the positive control, galantamine. [ABSTRACT FROM AUTHOR]

Due to their protective functions and medicinal effects, phenylethanoid glycosides (PhGs) have received much attention in recent decades. However, the information on their behavior in response to biotic stress is very limited. Also, the diversity of detected PhGs is low in different plants. Thus, the effect of Piriformospora indica culture filtrate on the production of PhGs and other defense reactions of Scrophularia striata cell culture as an important medicinal plant was investigated. Besides, we made an attempt to detect more PhGs in the species. The results revealed that hydrogen peroxide (H2O2) content increased in the early hours of treatment, while the malondialdehyde (MDA) level remained unchanged. The antioxidant enzymes superoxide dismutase (SOD) and guaiacol peroxidase (POX) also become activated to regulate the oxidative status in response to the fungal culture filtrate (FCF). The primary and secondary metabolites profile shifted towards defense compounds accumulation. Different precursor molecules levels including glucose, phenylalanine, tyrosine, arginine, methionine, cinnamic and coumaric acids decreased in the early hours, whereas sucrose and defensive compounds flavonoids and PhGs (echinacoside and acteoside) increased. Phenylalanine ammonia-lyase (PAL) and cinnamyl alcohol dehydrogenase (CAD) enzymes activity enhanced in S. striata treated cells. Furthermore, based on NMR spectroscopy and ESI/MS techniques, two PhGs of scrophuloside B1 and scroside D were detected for the first time in this species. The observations suggest that S. striata's defense system is activated by stimulating the antioxidant enzymes activity and modulating the profiles of carbohydrates, amino acids and phenolic compounds in response to P. indica elicitation. Key message: Piriformospora indica culture filtrate treatment through modulating the oxidative status, reprogramming primary metabolites and accumulating phenolic compounds specially phenylethanoid glycosides, leads to activation of defense system in Scrophularia striata cell culture. [ABSTRACT FROM AUTHOR]

Chemical investigation of the stems and leaves of Passiflora edulis Sims led to the isolation of a pair of phenylethanoid glycosides (1, 2), two benzyl alcohol glycosides (3, 4), and two cyanogenic glycosides (5, 6). Compounds 1 and 2 were an inseparable mixture in a 1:2 ratio. The structures were identified by spectroscopic analysis and comparison with literature data. Compound 1 was a new phenylethanoid alloside, and compound 2 was found in this plant for the first time. [ABSTRACT FROM AUTHOR]

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 1β (IL-1β) 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-1β 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. [ABSTRACT FROM AUTHOR]

Abstract 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.

Diabetes mellitus (DM) is a chronic metabolic disorder and is associated with impaired wound healing. Non-healing leg and foot ulcers are a frequent significant consequence of diabetes and are caused by a combination of inadequate tissue perfusion, suppression of re-epithelialization, and poor collagen production. Receptor for Advanced Glycation End Products (RAGE) is a multiligand cell surface molecule that belongs to the immunoglobulin superfamily and is crucial in the pathophysiology of poor wound healing in diabetics. By inhibiting RAGE, a chronic non-healing wound is more likely to undergo angiogenesis, enhance blood supply to hypoxic areas of the wound, and decrease the pro-inflammatory reaction and pro-apoptotic signaling. Phenylethanoid glycosides (PhGs) are a class of natural glycosides that possess anti-diabetic, wound-healing, antimicrobial, anti-inflammatory, and antioxidant properties. Echinacoside, a phenylethanoid glycoside, has a promising role in wound healing by enhancing angiogenesis, promoting keratinocyte migration and proliferation, and enhancing neutrophil and macrophage activity. Consequently, molecular docking was performed to assess the interaction between Echinacoside and the RAGE receptor (PDB ID: 6VXG). The ligand and receptor had a strong binding interaction, as indicated by the lowest binding energy, which was found to be −6.1 kcal/mol. To further assess the activity of Echinacoside in diabetic wound healing, in vitro and in vivo studies are needed.

In the present study, variations in levels of amino acids and carbohydrates in Scrophularia striata Boiss. were investigated at different growth phases in two in-vitro culture systems; namely shake flask and bioreactor by high-performance liquid chromatography (HPLC). The maximum contents of phenylalanine, tyrosine,and rhamnose were determined at 25th day of cell culture in shake flask and 10th day of cell culture in bioreactor while, the maximum content of glucose was observed at 15th day in shake flask and at 25th day in bioreactor. It seems that phenylalanine and tyrosine as precursors of phenylethanoid glycosides were directly related to biosynthetic pathway of phenylethanoid glycosides (PeGs) and also rhamnose and glucose content. In summary, analysis of primary metabolites in two culture systems showed that metabolism and cost of energy of amino acids and carbohydrates during cell culture of S. striata play a critical role in production of PeG compounds. Obtaining high levels of sucrose in S. striata cell culture in bioreactor reflected higher energy demands. It seems that the bioreactor shows higher rates of the produced amino acids as precursors for glycolysis and tricarboxylic cycles. Moreover, metabolism rate of amino acids was increased to supply enough energy and C-skeletons for biosynthesis of N-containing metabolites as well as secondary metabolites. In this study, potential capacity of S. striata cells for synthesis of amino acids and carbohydrates was also compared in both shake flask and bioreactor systems. Key message: Amino acids and carbohydrates metabolism and cost of energy during cell culture of S. striata play a critical role in production of PeGs compounds such as acteoside and echinacoside. Amino acids metabolism to supply enough energy and C-skeletons for the biosynthesis of N-containing metabolites as well as secondary metabolites has been increased. Too, the bioreactor may supply enough energy and C-skeletons for the biosynthesis of N-containing metabolites [ABSTRACT FROM AUTHOR]

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.

Cymbaria daurica L. is widely used in traditional Mongolian medicine for the treatment of impetigo, psoriasis, pruritus, fetotoxicity, and diabetes. Therefore, the anti-inflammatory and α-glucosidase-inhibitory activities of four polar C. daurica extracts (water, n-butanol, ethyl acetate, and petroleum ether extract) were preliminarily evaluated to identify the active extracts. We also investigated the chemical composition of the active extracts by phytochemical analysis. The n-butanol and ethyl acetate extracts exhibited significant (p < 0.05) anti-inflammatory activities by inhibiting lipopolysaccharide-induced nitric oxide (NO) production in RAW 264.7 cells. None of the tested extracts exhibited cytotoxic effects at the effective concentrations. The ethyl acetate extract significantly inhibited α-glucosidase activity, and the inhibition potency was equivalent to that of acarbose (p > 0.05). The n-Butanol extract presented the second highest inhibitory activity. As the n-butanol and ethyl acetate extracts were found to have potent anti-inflammatory and α-glucosidase-inhibitory activities, we separated and identified 10 compounds from the extracts. Among them, vanillic acid, cistanoside F, echinacoside, arenarioside, verbascoside, isoacteoside, and tricin were isolated from C. daurica for the first time. Further, 30 compounds from the n-butanol and ethyl acetate extracts of C. daurica were identified using UHPLC-Q-Exactive. The present study demonstrates for the first time that C. daurica contains phenylethanoid glycosides. In addition, this novel HPLC method was subsequently used for simultaneous identification of five compounds in the n-butanol and ethyl acetate extracts of C. daurica. This study provides a chemical basis for further characterization and utilization of C. daurica, which could be a potential source of novel anti-diabetic and anti-inflammatory agents.

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.

• A cell-line of Buddleja cordata as a system to enhance verbascoside production • Effects of precursor L-Phe and elicitor MeJa on Buddleja cordata cell suspensions • Addition of precursor or elicitor is better during the mid-exponential phase • L-Phe (600 µM) addition reached the highest production of VB (1.96 g L−1) • Maximum VB production occurred after elicitation (50 µM) (4.97 g L−1) • Verbascoside yields exceed those elsewhere reported with other in vitro systems Buddleja cordata Kunth (Scrophulariaceae) is an important medicinal herb widespread in Mexico that produces diverse phenolic compounds; among others, the pharmacologically important phenylethanoid glycoside (PeG) verbascoside (VB, also named acteoside). This work describes the effects of the metabolic precursor, L-phenylalanine (L-Phe), and the elicitor, methyl jasmonate (MeJa), on biomass accumulation and VB production in a B. cordata cell-line under suspension culture conditions. Cultures were exogenously fed with different concentrations of the precursor and elicitor at the early and late stages of the exponential growth phase. Precursor or elicitor addition was most effective when added in the late-exponential phase. Cultures fed with 600 µM L-Phe reached the highest production of VB after a 10-day exposure time (1.96 g L−1, which was 130% higher than in control cultures). Maximum VB production after elicitation (4.8 g L−1, with an overall increase of 213% above control level) occurred with 50 µM MeJa after an exposure time of 48 h. VB production yields reported in this work exceed those of previously reported biotechnological efforts using cell suspension cultures and other in vitro systems to increase phenylethanoid glycosides production, especially, VB. [ABSTRACT FROM AUTHOR]

• Five iridoid glucosides and five phenylethanoid glycosides were isolated from Plantago major. • Two new compounds, 10-acetylarborescoside (1) and plantainoside G (6) were elucidated. • This is the first report of phenylethanoid glycoside containing a seco -glucose moiety from natural sources. • Their inhibitory effects on NO production in BV2 cells were evaluated. Using various chromatographic separations, five iridoid glucosides (1 ― 5) and five phenylethanoid glycosides (6 ― 10) were isolated from the Plantago major whole plants and included two new compounds: 10-acetylarborescoside (1) and plantainoside G (6). Their structures were elucidated by detailed analysis of 1D and 2D NMR data, HR QTOF MS data, and experimental and calculated ECD data. The isolated compounds exhibited moderate inhibitory effects on NO overproduction in LPS-stimulated BV2 microglial cells, with IC 50 values ranging from 44.2–62.3 μM. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

As part of our continuing efforts to explore bioactive compounds from natural resources, a new iridoid glycoside, adoxosidic acid-6′-oleuroperic ester (1), together with one known phenylethanoid glycoside (2) and two known flavonoid glycosides (3–4) were isolated from the fruit of Forsythia suspensa. The structure of the new compound (1) was elucidated through 1D and 2D NMR spectroscopic data and HR-ESIMS. Interestingly, compound 1 was a monoterpene ester of one iridoid glycoside. Compounds 2–4 were identified as calceolarioside A (2), kaempferol-3-O-rutinoside (3), kampferol-3-O-robinobioside (4) on the basis of NMR spectroscopic data analyses and comparison with the data reported in the literature. The antiviral activity aganisist influenza A (H5N1) virus of compound 1 was studied as well. [ABSTRACT FROM AUTHOR]

Cymbaria daurica L. is widely used in traditional Mongolian medicine for the treatment of impetigo, psoriasis, pruritus, fetotoxicity, and diabetes. Therefore, the anti-inflammatory and α-glucosidase-inhibitory activities of four polar C. daurica extracts (water, n-butanol, ethyl acetate, and petroleum ether extract) were preliminarily evaluated to identify the active extracts. We also investigated the chemical composition of the active extracts by phytochemical analysis. The n-butanol and ethyl acetate extracts exhibited significant (p < 0.05) anti-inflammatory activities by inhibiting lipopolysaccharide-induced nitric oxide (NO) production in RAW 264.7 cells. None of the tested extracts exhibited cytotoxic effects at the effective concentrations. The ethyl acetate extract significantly inhibited α-glucosidase activity, and the inhibition potency was equivalent to that of acarbose (p > 0.05). The n-Butanol extract presented the second highest inhibitory activity. As the n-butanol and ethyl acetate extracts were found to have potent anti-inflammatory and α-glucosidase-inhibitory activities, we separated and identified 10 compounds from the extracts. Among them, vanillic acid, cistanoside F, echinacoside, arenarioside, verbascoside, isoacteoside, and tricin were isolated from C. daurica for the first time. Further, 30 compounds from the n-butanol and ethyl acetate extracts of C. daurica were identified using UHPLC-Q-Exactive. The present study demonstrates for the first time that C. daurica contains phenylethanoid glycosides. In addition, this novel HPLC method was subsequently used for simultaneous identification of five compounds in the n-butanol and ethyl acetate extracts of C. daurica. This study provides a chemical basis for further characterization and utilization of C. daurica, which could be a potential source of novel anti-diabetic and anti-inflammatory agents. [ABSTRACT FROM AUTHOR]

Cistanche deserticola (CD) is one of the two authoritative source plants of Cistanches Herba, a well-known medicinal plant. Herein, 1H NMR spectroscopy was employed to characterize the chemical profile and to distinguish the different parts, as well as to propose a new processing workflow for CD. Signal assignment was achieved by multiple one and two dimensional NMR spectroscopic techniques in combination with available databases and authentic compounds. The upper parts of the plant were distinguished from the lower parts by combining 1H NMR spectroscopic dataset with multivariate statistical analysis. A new processing method that hyphenated steaming with freeze-drying, was demonstrated to be superior to either steaming coupled with oven-drying or direct freeze-drying via holistic 1H NMR-based metabolomic characterization. Phenylethanoid glycosides, mainly echinacoside and acteoside, were screened out and confirmed as the chemical markers responsible for exhibiting the superiority of the new processing workflow, whereas serial primary metabolites, especially carbohydrates and tricarboxylic acid cycle metabolites, were found as the primary molecules governing the discrimination between the upper and lower parts of the plant. Collectively, 1H NMR spectroscopy was demonstrated as a versatile analytical tool to characterize the chemical profile and to guide the in-depth exploitation of CD by providing comprehensive qualitative and quantitative information.

Graphical abstract Twenty-nine compounds including four new ones of two butenolides, a triterpenoid and a phenylethanoid glycoside, were isolated from Plantago depressa. Selective compounds showed anti-inflammatory and antiradical activities. Highlights • Twenty-nine compounds were obtained from the whole plants of Plantago depressa. • Among them, four compounds are new. • The structures were elucidated by comprehensive spectroscopic analyses. • Some compounds showed anti-inflammatory and antiradical properties. Abstract Four new compounds, including two butenolides (1 and 2), an arborinane-type triterpenoid (3) and a phenylethanoid glycoside (4), along with the known triterpenoids (5 – 17) and phenylethanoid glycosides (18 – 29), were isolated from whole plants of Plantago depressa. The structures of the isolated compounds were elucidated by comprehensive spectroscopic analyses and were evaluated for their anti-inflammatory or antiradical activities. Our results underlined that, among compounds 1 – 17 , only compound 16 inhibited lipopolysaccharide-induced NO production with an IC 50 equal to 5.33 ± 0.51 μM. All phenylethanoid glycosides (4 , 18 – 29) were evaluated for their antiradical activity with a DPPH radical scavenging bioassay and showed high to moderate effect (IC 50 from 2.70 to 51.51 μM). [ABSTRACT FROM AUTHOR]

A new phenylethanoid glycoside, named cis-alyssonoside (1), was isolated from the leaves of Callicarpa nudiflora, along with four known phenylethanoid glycosides (2–5). Their structures were determined on the basis of extensive spectroscopic analysis and comparison with literature data. The inhibitory effects on lipopolysaccharide induced nitric oxide (NO) production in RAW264.7 cells of all the compounds were evaluated. [ABSTRACT FROM AUTHOR]

The MTT assay, as a screening method, has been widely used to measure the viability and proliferation of cells. However, it should be noted that MTT assay may not accurately reflect the effect of Cistanche tubulosa ethanolic extract on EA.hy926 cells viability. To investigate and identity the components responsible for the contradictory observations of the MTT assay, echinacoside and acteoside, two main phenylethanoid glycosides, from C. tubulosa ethanolic extract were isolated. The data derived from CCK-8, Hoechst 33342 and annexin V-FITC/PI assays suggest that the caffeyl group present in both isolated compounds was responsible for the conflicting results of the MTT assay. These data emphasize the need of using a variety of different methods to determine the effect of medicinal agents on cell viability to avoid generating misleading results.

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., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Five undescribed lignans, three undescribed phenylethanoid glycosides and eight known compounds were isolated from the root of Isodon ternifolius (D.Don) Kudô (Lamiaceae). The structures of all of the isolated constituents were characterized by physical data analyses including NMR, MS and ECD. The anti-inflammatory activities of the isolates were evaluated based on their ability to inhibit NO, PGE2 and TNF- α production in LPS-induced RAW 264.7 macrophage cells. Six phenyl-naphthalene lignans, ternifoliuslignan A, ternifoliuslignan B, ternifoliuslignan C, ternifoliuslignan D, ternifoliuslignan E and 3-carboxy-6,7-dihydroxy-1-(3′,4′-dihydroxyphenyl) -naphthalene, can substantially inhibit the release of NO with IC 50 values in the range of 9.98–29.14 μM, which are better than the positive reference. These phenyl-naphthalene lignans could markedly decrease the secretions of PGE2 and TNF- α in LPS-induced RAW264.7 cells. Ternifoliuslignan C and ternifoliuslignan D decreased iNOS, COX-2 and NF- κ B/p65 protein expression. A preliminary structure-activity relationship among the phenyl-naphthalene lignans for the anti-inflammatory activity was discussed. [ABSTRACT FROM AUTHOR]

The three Forsythia species, F. suspensa, F. viridissima and F. koreana, have been used as herbal medicines in China, Japan and Korea for centuries and they are known to be rich sources of numerous pharmaceutical metabolites, forsythin, forsythoside A, arctigenin, rutin and other phenolic compounds. In this study, de novo transcriptome sequencing and assembly was performed on these species. Using leaf and flower tissues of F. suspensa, F. viridissima and F. koreana, 1.28-2.45-Gbp sequences of Illumina based pair-end reads were obtained and assembled into 81,913, 88,491 and 69,458 unigenes, respectively. Classification of the annotated unigenes in gene ontology terms and KEGG pathways was used to compare the transcriptome of three Forsythia species. The expression analysis of orthologous genes across all three species showed the expression in leaf tissues being highly correlated. The candidate genes presumably involved in the biosynthetic pathway of lignans and phenylethanoid glycosides were screened as co-expressed genes. They express highly in the leaves of F. viridissima and F. koreana. Furthermore, the three unigenes annotated as acyltransferase were predicted to be associated with the biosynthesis of acteoside and forsythoside A from the expression pattern and phylogenetic analysis. This study is the first report on comparative transcriptome analyses of medicinally important Forsythia genus and will serve as an important resource to facilitate further studies on biosynthesis and regulation of therapeutic compounds in Forsythia species. [ABSTRACT FROM AUTHOR]

The tea-like beverage Stevia rebaudiana Bertoni (Stevia) is popular in China because it reduces blood glucose and has a sweet taste. In this work, a comprehensive quality assessment of Stevia led to the discovery of five phenylethanoid glycosides, namely steviophethanoside (1), cuchiloside (2), salidroside (3), icariside D (4), and tyrosol (5). Of them, compound 1 is a novel compound. Mass spectrometry and NMR spectroscopy were employed to confirm the absolute configuration. A hydrolytic step with 4 N TFA at 95 °C for 4 h was used to confirm the monosaccharides. In addition, Discovery Studio 4.0 was used to predict the ADME and toxicity activity of compound 1. The results suggested that compound 1 was biocompatible and had poor toxicity, which was verified by rat INS-1 islet β cells through an MTT assay. Meanwhile, a significant stimulatory effect on INS-1 cells was observed, which indicated a hypoglycemic effect of compound 1. This is the first report that describes a natural, novel, and hypoglycemic phenylethanoid glycoside in Stevia.

Cistanche deserticola (CD) is one of the two authoritative source plants of Cistanches Herba, a well-known medicinal plant. Herein, 1 H NMR spectroscopy was employed to characterize the chemical profile and to distinguish the different parts, as well as to propose a new processing workflow for CD. Signal assignment was achieved by multiple one and two dimensional NMR spectroscopic techniques in combination with available databases and authentic compounds. The upper parts of the plant were distinguished from the lower parts by combining 1 H NMR spectroscopic dataset with multivariate statistical analysis. A new processing method that hyphenated steaming with freeze-drying, was demonstrated to be superior to either steaming coupled with oven-drying or direct freeze-drying via holistic 1 H NMR-based metabolomic characterization. Phenylethanoid glycosides, mainly echinacoside and acteoside, were screened out and confirmed as the chemical markers responsible for exhibiting the superiority of the new processing workflow, whereas serial primary metabolites, especially carbohydrates and tricarboxylic acid cycle metabolites, were found as the primary molecules governing the discrimination between the upper and lower parts of the plant. Collectively, 1 H NMR spectroscopy was demonstrated as a versatile analytical tool to characterize the chemical profile and to guide the in-depth exploitation of CD by providing comprehensive qualitative and quantitative information. [ABSTRACT FROM AUTHOR]

Three new phenylethanoid glycosides, 2-(3-hydroxy-4-methoxyphenyl)ethyl 1- O -β- d -allopyranoside (hodgsonialloside A, 1 ), 2-(3-hydroxy-4-methoxyphenyl)ethyl 1- O -β- d -glucopyranosyl-(1 → 4)-β- d -allopyranoside (hodgsonialloside B, 2 ) and 2-(3-methoxy-4-hydroxyphenyl)ethyl 1- O -β- d -allopyranoside (hodgsonialloside C, 3 ) were isolated from the leaves of Magnolia hodgsonii in addition to six known compounds, tyrosol 4- O -β- d -xylopyranosyl-(1 → 6)-β- d -glucopyranoside ( 4 ), kaempferol 3- O -neohesperidoside ( 5 ), kaempferol 3- O -rutinoside ( 6 ), kaempferol 3- O -α- l -rhamnopyranosyl-(1 → 2)-[α- l -rhamnopyranosyl-(1 → 6)]-β- d -glucopyranoside ( 7 ), (+)-syringaresinol O -β- d -glucopyranoside ( 8 ), and oblongionoside C ( 9 ). The structure elucidation of these compounds was based on analyses of physical and spectroscopic data including 1D and 2D NMR experiments. [ABSTRACT FROM AUTHOR]

The primary aim of the present study was to develop a novel microemulsion (ME) formulation to deliver phenylethanoid glycoside (PG) for use in skin lighteners and sunscreens. The oil phase was selected on the basis of drug solubility, while the surfactant and cosurfactant were screened and selected on the basis of their solubilizing capacity and the efficiency with which they formed MEs. Pseudoternary phase diagrams were constructed to evaluate ME regions and five formulations of oil-in-water MEs were selected as vehicles. In vitro skin permeation experiments were performed to optimize the ME formulation and to evaluate its permeability in comparison to that of saline solution. The physicochemical properties of the optimized ME and the permeating ability of PG delivered by this ME were also investigated. The optimized ME formulation was composed of isopropy myristate (7%, w/w), Cremorphor EL (21%, w/w), propylene glycol (7%, w/w) and water (65%, w/w). The cumulative amount of PG that permeated through excised mouse skin when carried by ME was ∼1.68 times that when PG was carried by saline solution only. The cumulative amount of PG in the microemulsion (4149.650±37.3 μg'cm-2) was significantly greater than that of PG in the saline solution (2288.63±20.9 μg'cm-2). Furthermore, the permeability coefficient indicated that optimized microemulsion was a more efficient carrier for transdermal delivery of PG than the control solution (8.87±0.49 cm/hx10-3 vs. 5.41±0.12 cm/hx10-3). Taken together, the permeating ability of ME-carried PG was significantly increased compared with saline solution. [ABSTRACT FROM AUTHOR]

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. To evaluate the neuroprotective effect of S. incarnata roots and its chemical constituents against C 2 -ceramide-induced cell death in Cath.-a-differentiated (CAD) cells. 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 C 2 -ceramide of S. incarnata root extract, fractions and isolated compounds were assessed in CAD cells. S. incarnata root extract and its n -butanol fraction were not cytotoxic but showed neuroprotective effects against C 2 -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 C 2 -ceramide without inducing cytotoxic effects. 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. [Display omitted] • The neuroprotective effect of S. incarnata root extract provides an ethnopharmacological explanation for its traditional use. • The bioactive stachysoside C and a new compound, incarnatoside, are reported for the first time in the genus Scutellaria. • Neuroprotective phenylethanoid glycosides from S. incarnata root provides new understanding of its bioactive constituents. [ABSTRACT FROM AUTHOR]

Seven phenolic compounds, including a new phenylethanoid glycoside, were isolated from the ethyl acetate fraction of an aqueous ethanol extract of Plantago Herb (whole part of Plantago asiatica L.), which showed significant antioxidative activity. The new compound was characterized as 2-(3,4-dihydroxyphenyl)ethyl 3-O-β-D-allopyranosyl-6-O-caffeoyl-β-D-glucopyranoside on the basis of spectral and chemical evidence, and its antioxidant activity was comparable to that of tea catechins.

Three phenylethanoid glycosides, echinacoside (1), salidroside (3), and acteoside (6), and three secoiridoid glycosides, isonuezhenide (2), nuezhenoside G13 (4), and specnuezhenide (5), have been extracted and separated by a combined method of ultrahigh pressure extraction (UPE) and high-speed counter-current chromatography (HSCCC) from Ligustri Lucidi Fructus. For the UPE, the optimal extraction was developed with conditions including solvent of 90% ethanol, sample to solvent ratio of 1:20 g/mL, pressure of 200 MPa, and time of 2 min, which rendered the yields of compounds 4 and 5 were 15.0 and 78.0 mg/g, respectively. For the HSCCC separation, the strategy of changing flow rates between 1.0 and 2.0 mL/min allowed the acquisition for 2.7 mg of compound 1, 4.5 mg of compound 2, 6.8 mg of compound 3, 5.9 mg of compound 4, 11.2 mg of compound 5, and 2.2 mg of compound 6 in one separation run under the solvent system of ethyl acetate:n-butanol:water (2:1:3, v/v) from 200 mg of the UPE extract. The structures of these phenylethanoid and secoiridoid glycosides were elucidated by extensive spectroscopic methods.

A new phenylethanoid glycoside acylated with syringic acid, namely acanmontanoside, was isolated from the aerial portions of Acanthus montanus (Nees). T. Anderson, along with decaffeoylverbascoside, verbascoside, isoverbascoside, leucosceptoside A, (2R)-2-O-b-D-glucopyranosyl-2H-1,4-benzoxazin-3(4H)-one (HBOA-Glc), (2R)-2-O-b-D-glucopyranosyl-4-hydroxy-2H-1,4-benzoxazin-3(4H)-one (DIBOA-Glc), (3R)-1-octen-3-ol-3-O-b-D-xylopyranosyl-(1→6)-O-b-D-glucopyranoside and ebracteatoside B. The structure elucidations were based on physical data and spectroscopic analyses including 1D- and 2D-NMR.

Three phenylethanoid glycosides (1, 2, 3) and one iridoid glycoside (4) were isolated from aerial parts of Veronica chamaedrys L. (Scrophulariaceae) for the first time. On the basis of spectral analysis, the structures of these compounds were determined to be acteoside (3,4-dihydroxy-β-phenylethoxy-O-α-L-rhamnopyranosyl-(1→3)-4-O-caffeoyl-β-D-glucopyranoside) (1), ehrenoside (3,4-dihydroxy-β-phenylethoxy-O-α-L-arabinopyranosyl-(1→2)-α-L-rhamnopyranosyl-(1→3)-4-O-caffeoyl-β-D-glucopyranoside) (2), chamaedroside (3,4-dihydroxy-β-phenylethoxy-O-α-L-rhamnopyranosyl-(1→3)-4-O-caffeoyl-α-L-arabinopyranoside) (3) and aucuboside (4).

Callicarpa nudiflora is a famous region drug of Hainan Province, which is mainly used as anti-inflammatory and hemostatic agents. The plant is rich in flavonoids and phenylethanoid glycosides, which have been proved to be one of the main source of natural antioxidants. To investigate the antioxidant capacities of C. nudiflora, the authors use DPPH scavenging method to determine the antioxidant activity of different polar extracts of C. nudiflora and its main constituents. The alcohol extract, water fraction, butyl alcohol fraction, ethyl acetate fraction showed strong antioxidant activity. Three main compounds, luteolin, luteolin-7-O-β-D-glucoside and acteoside, possessed significant antioxidant activity while 5-hydroxy-3,7,3',4'-tetramethoxyflavone exhibited weak antioxidant activity. The research will provide the evidence for development of health products of C. nudiflora. [ABSTRACT FROM AUTHOR]