Two new natural products from Portulaca oleracea L. and their bioactivities.

Two new natural products, belonging to alkaloids, identified as ((2R,3S,4R,5R)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-3,4-dihydroxytetrahydrofuran-2-yl)methyl acetate (1) and (5-hydroxypyridin-2-yl)methyl acetate (2), were isolated from Portulaca oleracea L. The structures were identified by spectroscopic methods, including 1D, 2D NMR, and UHPLC-ESI-QTOF/MS methods. Meanwhile, the anti-inflammatory and anticholinesterase bioactivities were found in these two compounds.

Simultaneous Determination of Three Compounds in Rat Plasma by UHPLC-QQQ-MS/MS and Its Application to Pharmacokinetics of Banxia Baizhu Tianma Tang.

A rapid and highly selective and sensitive ultra-high-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UHPLC-QQQ-MS/MS) method was applied to simultaneously determine ephedrine, gastrodin, and liquiritin in rat plasma. The three analytes and vitexin-2″-O-rhamnoside (I.S.) were analyzed on a Waters Acquity UPLC C18 column (1.7 µm, 2.1 mm × 100 mm) at 30°C with gradient mobile phase consisting of 0.1% formic acid aqueous solution (A) and acetonitrile (B) after one-step direct protein precipitation with acetonitrile. The detection was performed by multiple reaction monitoring (MRM) mode via electrospray ionization (ESI) source in positive and negative ion modes. The product ions m/z 166.1⟶148.1, 285.1⟶123.1, 417.1⟶255.1, and 579.0⟶433.1 were used for determination of ephedrine, gastrodin, liquiritin, and I.S., respectively. The calibration curves of the three analytes were linear with r 2 greater than 0.994. The intra and interday precision RSD% was less than 11.5 and 13.4. The intra and interday precision RE% was between -10.4% and 9.33%. The average extraction recoveries of the three analytes were no less than 86.88 ± 1.08%. The developed and validated method was for the first time applied to the pharmacokinetics of three compounds in rat plasma after intragastric administration of Banxia Baizhu Tianma Tang.

Two new homoisoflavones from Portulaca oleracea L. and their activities.

Two new compounds, identified as 3-(2-hydroxybenzyl)-6,8-dimethoxy-4H-chromen-4-one (1), named oleracone J and 3-(2-hydroxybenzyl)-6,8-dimethoxychroman-4-one (2), named oleracone K, were isolated from Portulaca oleracea L., and the structures of them were determined by spectroscopy, including one-dimensional and two-dimensional nuclear magnetic resonance, high-resolution electrospray ionisation time-of-flight mass spectrometry. The two compounds have scavenging activities in 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical quenching assay, with IC50 values of 18.34, 23.92 µM, and anticholinesterase activities with IC50 values of 59.08, 67.89 µM, respectively.

Three new alkaloids from Portulaca oleracea L. and their bioactivities.

Three novel alkaloids, named oleracone L (1), portulacatone B (2), and portulacatal (3), were isolated from P. oleracea L.. The structures were determined using UV, IR, 1D and 2D NMR spectroscopy and UHPLC-ESI-QTOF/MS. The three compounds in a dose-dependent manner significantly reduced the secretion of IL-1ß in the lipopolysaccharide-stimulated macrophages RAW 264.7 cell culture supernatant, moreover, exhibited the anticholinesterase activities.

A new skeleton flavonoid and a new lignan from Portulaca oleracea L. and their activities.

A new skeleton flavonoid, identified as (5aR)-10-hydroxy-8-methoxy-5aH,11H-chromeno[2,3-b]chromen-11-one (1), named oleracone G, and a new lignan, confirmed as 8-(4-hydroxy-3-methoxyphenyl)-3-methoxynaphthalen-2-ol (2), named oleralignan B, were isolated from Portulaca oleracea L., and the structures of them were determined using spectroscopic methods including UV, IR, 1D NMR, 2D NMR, and UHPLC-ESI-QTOF/MS. In addition, compounds 1-2 were applied to investigate the anti-inflammatory activities on lipopolysaccharide-stimulated macrophages and scavenging effects in 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical. The results showed that the two compounds at 10 µM and 20 µM could dose-dependently decrease the secretion of interleukin 1ß in RAW 264.7 cells by enzyme-linked immunosorbent assay, moreover, presented remarkable antioxidant activities with IC50 values of 27.57, 20.12 µM, respectively.

Two new amide alkaloids from Portulaca oleracea L. and their anticholinesterase activities.

Two new amide alkaloids, identified as 5,6-dihydroxy-3,4-dihydroisoquinolin-1(2H)-one, named oleraciamide G (1) and (E)-1-(5-hydroxy-6-((3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)oxy)-1H-indol-1-yl)-3-(4-hydroxyphenyl)prop-2-en-1-one, named oleraindole D (2) were obtained from Portulaca oleracea L. Their structures were determined by spectroscopic methods, including the 1 D and 2 D NMR, high-resolution electrospray ionization time-of-flight mass spectrometry. In addition, compounds 1 and 2 presented anticholinesterase activities with IC50 values of 65.71 ± 0.15 µM and 58.78 ± 0.36 µM, respectively.

Bioactivities of 7'­ethoxy­trans­feruloyltyramine from Portulaca oleracea L. and its metabolism in rats using ultra­high­performance liquid chromatography electrospray coupled with quadrupole time­of­flight mass spectrometry.

This research aims to study the antioxidation and anticholinesterase activities of 7'-ethoxy-trans-feruloyltyramine (ETFT), which was an alkaloid isolated from Portulaca oleracea for the first time. Furthermore, its main metabolites and metabolic pathways in rats were also explored. The antioxidation and anticholinesterase effects of ETFT were, respectively, examined using 1,1-diphenyl-2-picrylhydrazyl assay and modified Ellman's method. The results showed that ETFT exhibited both the good antioxidant and anticholinesterase effects. Its main metabolites in rats were implemented, and nine metabolites were finally found in the rat's plasma and urine, including the oxidation, reduction, hydrolysis, glucuronidation, sulfation, and glutathionylation process.

Investigating the bioavailabilities of olerciamide A via the rat's hepatic, gastric and intestinal first-pass effect models.

Olerciamide A (OA) is a new alkaloid isolated from Portulaca oleracea L. that has been proved to possess a low bioavailability (F) after oral administration in rats in our previous study. Hence, to clarify the reasons for its low bioavailability, hepatic, gastric and intestinal first-pass effect models were established, and a rapid, sensitive UHPLC method was validated and applied for the determination after dosing via the femoral, portal, gastric and intestinal routes. As inhibitors of CYP3A and P-gp, verapamil, midazolam and borneol in low and high dose groups were selected to improve the low bioavailability of olerciamide A. Moreover, a rectal administration method was also carried out to improve the bioavailability of olerciamide A. The results showed that the bioavailability of olerciamide A using hepatic, gastric and intestinal routes were 92.16%, 84.88% and 5.76%, respectively. The areas under the plasma concentration-time curve from zero to infinity (AUC0 → ∞ ) were increased a little after being dosed with 10 and 30 mg/kg verapamil (p > 0.05), but markedly increased after being dosed with 0.4 and 1.2 mg/kg midazolam as well as 8 and 24 mg/kg borneol (p < 0.05). Besides, the AUC0 â†’ ∞ values after the lower and upper rectal administrations were separately similar to the intravenous and intraportal administrations. Our study showed that the intestinal first-pass effect mainly contributed to the low bioavailability of olerciamide A in rats due to it being a substrate of CYP3A and P-gp as well as to its poor intestinal absorption.

A new homoisoflavone from Portulaca oleracea L. and its antioxidant activity.

A new compound was identified as 3-(2-hydroxybenzyl)-5,7-dimethoxy-4H-chromen-4-one (or 2'-dihydroxy-5,7-dimethoxy-homoisoflavone), oleracone F (1), together with p-hydroxy ethyl cinnamate (2) and 4-hydroxy-3-methoxy ethyl cinnamate (3) isolated from the Portulaca oleracea L. for the first time and six known compounds, salicylic acid (4), ß-carboline-3-carboxylic acid (5), aurantiamide (6), portulacanone A (7), B (8) and C (9). Their structures were determined using spectroscopic methods, including one- and two-dimensional nuclear magnetic resonance and high-resolution electrospray ionization time-of-flight mass spectrometry. Notably, oleracone F (1) presented scavenging activity in 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical quenching assay, with IC50 value of 17.78 µM.

Pharmacokinetic studies of soyalkaloid A from Portulaca oleracea L. using ultra high-performance liquid chromatography electrospray ionization quadrupole-time of flight mass spectrometry and its antioxidant activity.

Soyalkaloid A was isolated from Portulaca oleracea L. for the first time in our laboratory and then a rapid and sensitive ultra-high-performance liquid chromatography electrospray ionization quadrupole-time of flight mass spectrometry (UHPLC-ESI-Q-TOF/MS) method with hesperidin as internal standard (IS) was developed and validated to investigate the pharmacokinetics of soyalkaloid A in rats after oral and intravenous administrations. The analysis was achieved on an Agilent Zorbax Eclipse Plus C18 Column (2.1 × 50 mm, 1.8 µm) by elution with acetonitrile and water (containing 0.1% formic acid), at a flow rate of 0.3 mL/min. The MS analysis was performed in the positive ion mode with monitored ion m/z 227.0814 [M + H]+ and 611.1971 [M + H]+ for soyalkaloid A and IS, respectively. The linear range was established over the concentration range 7.5-6000 ng/mL (r = 0.9951). The intra- and inter-assay accuracy and precision were between -4.86-4.49 and 1.93-9.66, respectively. The lower limits of detection and quantitation observed were 2.1 and 7.4 ng/mL, respectively. The rapid, sensitive and specific UHPLC-ESI-Q-TOF/MS method was successfully applied to a pharmacokinetic study of soyalkaloid A. Moreover, its antioxidant was studied via a 1,1-diphenyl-2-picryl-hydrazyl radical scavenging assay, the IC50 value being 20.73 ± 0.51 µM.

A pharmacokinetic study on oleracone C after oral and intravenous administration.

Oleracone C, a new homoisoflavanone recently isolated from the plant Portulaca oleracea L., has obvious pharmacological activities. Subsequently, its pharmacokinetic profiles in rats' plasma after oral and intravenous administrations were studied by a simple and rapid ultra high-performance liquid chromatography electrospray ionization quadrupole-time of flight mass spectrometry (UHPLC-ESI-Q-TOF/MS) with apigenin as an internal standard (IS). The analysis was performed on an Agilent Zorbax Eclipse Plus C18 Column (2.1 × 50 mm, 1.8 µm) by elution with acetonitrile and water (containing 0.1% formic acid) at a flow rate of 0.3 mL/min. Electrospray ionization in negative ion mode was used to quantify oleracone C and apigenin, with monitored ion m/z values of 299.0915 [M - H]- and 269.0455 [M - H]-. The linear range was established over the concentration range 10-2000 ng/mL (r = 0.9971). The limit of detection (LOD) and limit of quantification (LOQ) were 3 and 10 ng/mL for oleracone C, respectively. The RSD and RE of intra- and inter- day accuracy and precision were all less than 15%. The pharmacokinetic results indicated that oleracone C was rapidly distributed with the time to peak concentrations of 0.03 h and 0.33 h, respectively after intravenous and oral administrations and presented a low absolute bioavailability of 8.32%. This is the first study to successfully examine the pharmacokinetics of homoisoflavanone in rats' plasma after oral and intravenous administrations, using rapid, sensitive and specific UHPLC-ESI-Q-TOF/MS method.

Pharmacokinetics and metabolism of olerciamide A from Portulaca oleracea L. in rats by UHPLC-UV and UHPLC-ESI-Q-TOF/MS.

The aim of this study was to elucidate the pharmacokinetics of olerciamide A in rats after oral and intravenous administration of Portulaca oleracea L. extract by a simple and rapid ultra high-performance liquid chromatography method with bergapten as internal standard. The pharmacokinetic results indicated that olerciamide A was rapidly distributed with a time to peak concentration of 30 min after oral administration and presented a low oral absolute bioavailability of 4.57%. The metabolism of olerciamide A in rats was also investigated using ultra-high-performance liquid chromatography electrospray coupled with quadrupole-time of flight mass spectrometry to elucidate the reason for the low absolute bioavailability of olerciamide A and seven metabolites of oleraciamide A were found in rat plasma and urine.

A new lactam alkaloid from Portulaca oleracea L. and its cytotoxity.

A new lactam alkaloid named oleraciamide D (1), indentified as (5R)-4-(3-methoxy-4-hydroxyphenyl)-5-(4-hydroxyphenyl)-5,6-dihydropyridin-2(1H)-one, together with five known compounds, indole-3-aldehyde (2), portulacatone (3), N-trans-feruloyloctopamine (4), N-trans-feruloyl-3'-O-methyldopamine (5) and N-trans-feruloyltyramine (6) were isolated from Potulaca oleracea L. Among them, indole-3-aldehyde (2) was isolated from the medicine for the first time. The structure of the new alkaloid was elucidated via UHPLC-ESI-Q-TOF/MS, 1D NMR and 2D NMR. The five known compounds were established by comparing the 1H-NMR and 13C NMR with the reported literature. Oleraciamide D (1) showed cytotoxicity against SH-SY5Y cells when concentration at 50 uM by CCK-8 method.

Two new similar alkaloids from Portulaca oleracea L.

Two novel alkaloids named oleraciamide A (1) and oleraciamide B (2) were isolated from Portulaca oleracea L., and spectroscopic methods including 1D and 2D nuclear magnetic resonance and high-resolution electrospray ionisation quadrupole-time of flight mass spectrometer spectrometry techniques are employed to determine their structures. Oleraciamide A (1) was evaluated no cytotoxicity at concentrations up to 80 µM over 72 h against human adipose-derived stem cells (hADSCs) by CCK-8 method.

Correction to Three Novel Alkaloids from Portulaca oleracea L. and Their Anti-inflammatory Effects.

Oleracimine and oleracimine A were isolated from Portulaca oleracea L. and described in the J. Agric. Food Chem, but the alternative structures of the two compounds are proposed on the basis of NMR analyses.

A novel alkaloid from Portulaca oleracea L.

A novel alkaloid named oleraciamide C (1), with six known compounds, hydroxydihydrobovolide (2), uracil (3), catechol (4), 4-aminophenol (5), vanillic acid (6) as well as 3-hydroxypyridine (7), were isolated from Portulaca oleracea L. Additionally, hydroxydihydrobovolide (2), 4-aminophenol (5), 3-hydroxypyridine (7) were obtained from the plant for the first time. Structure of the new compound was determined using spectroscopic methods including HR-ESI-TOF-MS, 1D and 2D NMR. Others were elucidated through 1H NMR, 13C NMR spectra and comparison with literature data. Notably, Compound 1 possessed an unusual bis-substituted eight-membered ring linked with the ß-glucopyranose moiety. The cytotoxicity of compound 1 was evaluated against human adipose-derived stem cells (hADSCs) by CCK-8 method.

Three Novel Alkaloids from Portulaca oleracea L. and Their Anti-inflammatory Effects.

Three novel carbon skeleton alkaloids, named oleracimine (1), oleracimine A (2), and oleracone A (3), with one novel azulene carbon skeleton compound, oleracone B (4), and one known compound, ß-carboline (5), were first isolated from Portulaca oleracea L. The structures were determined using spectroscopic methods, including one- and two-dimensional nuclear magnetic resonance and high-resolution electrospray ionization time-of-flight mass spectrometry techniques. In addition, oleracimine (1) was used to investigate the anti-inflammatory effects on lipopolysaccharide-stimulated macrophages. The results of enzyme-linked immunosorbent assay, western blot, and real-time polymerase chain reaction showed that oleracimine (1) remarkably inhibited nitric oxide production and could dose-dependently decrease the secretions of interleukin 6, tumor necrosis factor α, nitric oxide, and prostaglandin E2 in cell culture supernatants as well as the mRNA of cyclooxygenase-2 and inducible nitric oxide synthase.

The anti-inflammation and pharmacokinetics of a novel alkaloid from Portulaca oleracea L.

OBJECTIVES: This study was to elucidate the pharmacokinetics of a novel alkaloid, 6-acetyl-2,2,5-trimethyl-2,3-dihydrocyclohepta[b]pyrrol-8(1H)-one, named oleracone isolated from Portulaca oleracea L., and to examine the anti-inflammatory ability with lipopolysaccharide (LPS) stimulated macrophages. METHODS: The novel alkaloid, oleracone, was isolated from Portulaca oleracea L., and its structure was determined by spectroscopic analysis including HRESIMS, 2D NMR spectroscopic data and single-crystal X-ray diffraction. The activity of anti-inflammation was assayed via the test with RAW 264.7 activated by LPS, and the pharmacokinetics of oleracone in rat plasma after intravenous and oral administration at dose of 2.5 mg/kg was, respectively, investigated by a rapid and sensitive ultra high-performance liquid chromatography (UHPLC) method with bergapten as internal standard. KEY FINDINGS: Oleracone was a novel alkaloid first isolated from Portulaca oleracea L. and possessed unique structure in natural products, whose anti-inflammatory effecting on nitrite oxide production and several pivotal pro-inflammatory cytokines was found at the concentration of 50 µm, and the pharmacokinetic results indicated that oleracone was rapidly distributed with Tmax of 15.7 min after oral administration and presented a higher oral absolute bioavailability to be 74.91 ± 10.7%. CONCLUSIONS: Oleracone as novel alkaloid presented remarkably anti-inflammatory effect, which was rapid distributed in rat with high bioavailability of 74.91 ± 10.7%.

Hepatic, gastric and intestinal first-pass effects of vitexin-2''-O-rhamnoside in rats by ultra-high-performance liquid chromatography.

Previous research in our laboratory found that the absolute bioavailability of vitexin-2''-O-rhamnoside (VR) was quite low at 4.89%. A rapid and sensitive UHPLC method using hesperidin as an internal standard was therefore developed and validated to investigate the reasons for this by determining VR in rat plasma after administering intravenously, intraportally (5 mg/kg), intraduodenally and intragastrically (40 mg/kg) to the rat model of the hepatic, gastric and intestinal first-pass effects. As only a high intestinal first-pass effect of VR was found, that is, there existed a low bioavailability of VR (2.40%), inhibitors of P-glycoprotein (P-gp) and cytochrome P450 3A (CYP3A), including verapamil, cyclosporin A and midazolam, and absorption enhancers, including bile salts and borneol, combined with VR, were instilled into duodenum to evaluate the effects on bioavailability of VR. The results demonstrated that area under the concentration-time curve (AUC) values of VR slightly increased after administration of verapamil, cyclosporin A and midazolam, indicating that CYP3A and P-gp do not play an important role in the first-pass effect in the intestine. AUC values of VR significantly increased after administering bile salts or borneol, indicating that the low bioavailability of VR was mainly related to its poor absorption in the intestine.

Hepatic, gastric, and intestinal first-pass effects of vitexin in rats.

CONTEXT: Recent research has demonstrated that vitexin exhibits a prominent first-pass effect. In this light, it is necessary to investigate the causes of this distinct first-pass effect. OBJECTIVE: The aim of this study was to evaluate hepatic, gastric, and intestinal first-pass effects of vitexin in rats and, furthermore, to investigate the role of P-glycoprotein (P-gp) and cytochrome P450 3A (CYP3A) in the absorption and secretion of vitexin in the duodenum. MATERIALS AND METHODS: Vitexin was infused into rats intravenously, intraportally, intraduodenally, and intragastrically (30 mg/kg). In addition, verapamil (50 mg/kg), a common substrate/inhibitor of P-gp and CYP3A, was also instilled with vitexin into the duodenum to investigate the regulatory action of P-gp and CYP3A. The plasma concentrations of vitexin were measured by the HPLC method using hesperidin as an internal standard. RESULTS: The hepatic, gastric, and intestinal first-pass effects of vitexin in rats were 5.2%, 31.3%, and 94.1%, respectively. In addition, the total area under the plasma concentration-time curve from zero to infinity (AUC) of the vitexin plus verapamil group and of the normal saline group was 44.9 and 39.8 µgc min/mL, respectively. DISCUSSION AND CONCLUSION: The intestinal first-pass effect of vitexin was considerable, and gastric and hepatic first-pass effects also contribute to the low absolute oral bioavailability of vitexin. The AUC of the vitexin plus verapamil group was slightly higher than that of the vitexin plus normal saline group (by approximately 1.13-fold), suggesting that verapamil does not play an important role in the absorption and secretion of vitexin.