A new C-glucoside from Commelina communis

Combining the In Silico and In Vitro Assays to Identify Strobilanthes cusia Kuntze Bioactives against Penicillin-Resistant Streptococcus pneumoniae

Leaves of Strobilanthes cusia Kuntze (S. cusia) are a widely used alexipharmic Traditional Chinese Medicine (TCM) in southern China for the prevention of cold and respiratory tract infectious diseases. One of the most common bacterial pathogens in the respiratory tract is the gram-positive bacterium Streptococcus pneumoniae. The antibiotic resistance of colonized S. pneumoniae makes it a more serious threat to public health. In this study, the leaves of S. cusia were found to perform antibacterial effects on the penicillin-resistant S. pneumoniae (PRSP). Confocal assay and Transmission Electron Microscopy (TEM) monitored the diminished cell wall integrity and capsule thickness of the PRSP with treatment. The following comparative proteomics analysis revealed that the glycometabolism-related pathways were enriched for the differentially expressed proteins between the samples with treatment and the control. To further delve into the specific single effective compound, the bio-active contents of leaves of S. cusia were analyzed by UPLC-UV-ESI-Q-TOF/MS, and 23 compounds were isolated for anti-PRSP screening. Among them, Tryptanthrin demonstrated the most promising effect, and it possibly inhibited the N-glycan degradation proteins, as suggested by reverse docking analysis in silico and further experimental verification by the surface plasmon resonance assay (SPR). Our study provided a research foundation for applications of the leaves of S. cusia as a TCM, and supplied a bio-active compound Tryptanthrin as a candidate drug skeleton for infectious diseases caused by the PRSP.

A Reliable LC-MS/MS Method for the Quantification of Two Pairs of Isomeric Flavonoids from Commelina Communis Linn in Rat Plasma: Validation and Pharmacokinetic Applications

Background:

Commelina communis Linn (Commelinae Herba) is a traditional Chinese medicine that can be used both as food and as medicine. It has been used to treat a variety of disorders, including a cold, high fever, sore throat, edema and oliguria for many years. Two pairs of isomeric flavonoid glycosides are the main active components in Commelina communis Linn, and they have a high content.

Objective:

The objective of this study was to determine the pharmacodynamic and pharmacological effects of Commelina communis Linn.

Method:

A sensitive, efficient, and rapid LC-MS/MS method was developed to simultaneously identify two pairs of isomeric flavonoid glycosides in rats. Chromatographic separation was carried out on a Wonda Cract ODS-2 C18 column (150 mm x 4.6 mm, 5 μm) using a mobile phase composed of 0.1% formic acid (aqueous solution) and methanol at a flow rate of 0.8 mL/min. The detection of the four analytes and the internal standard (IS) sulfamethoxazole was performed with multiple reaction monitoring (MRM) in negative electrospray ionization mode. All the analytes were eluted within 20 min.

Results:

This method was successfully applied for simultaneous identification of the concentrations of the four compounds in the plasma after the oral administration of 10 mL/kg Commelina communis Linn extract to rats. The pharmacokinetic study indicated that analytes reached their Cmax in approximately 15 min and could be detected until 12 h.

Conclusion:

The method complies with the State Food and Drug Administration guidelines for selectivity, sensitivity, accuracy, precision, matrix effect, extraction recovery and stability. This is the first report on the pharmacokinetics of Commelina communis Linn. The information gained from this research may be valuable for the preclinical and clinical applications of Commelina communis Linn.

Chemical Constituents from Sargassum fusiforme (Harv.) Setch

Phytochemical investigation of Sargassum fusiforme (Harv.) Setch. led to the discovery of fifteen secondary metabolites, including three sterols, three monoterpenes, five nitrogenous compounds, two fatty acids, and two others. Among them, two compounds are new, while the other thirteen compounds were isolated from S. fusiforme for the first time. The structures of the two new compounds were identified by NMR and HR-ESI-MS data analyses, and the absolute configurations were established by comparing the calculated and experimental ECD spectroscopic data.

Isolation, structural elucidation and in vitro hepatoprotective activity of flavonoids from Glycyrrhiza uralensis

Two new flavonoid glycosides, 2',4'-dihydroxydihydrochalcone-4-O-β-D-glucopyranoside (1) and medicarpin-3-O-β-D-apiofuranosyl (1 → 2)-β-D-glucopyranoside (2), together with 34 known flavonoids were isolated from the 75% EtOH extract of the dried roots of Glycyrrhiza uralensis Fisch. Their structures were elucidated on the basis of spectroscopic analyses. The flavonoids were classified into ten sub-types, namely, dihydrochalcone (1), pterocarpans (2-4), flavones (5-6), flavanones (7-11), chalcones (12-15), retro-chalcones (16-18), isoflavans (19-21), isoflavones (22-28), 3-arylcoumarins (29-30), and coumestans (31-36). The isolated flavonoids were evaluated for in vitro hepatoprotective activity against D-galactosamine-induced toxicity in human hepatoma HepG2 cells.

Identification of methanol-soluble compounds in sesame and evaluation of antioxidant potential of its lignans

The methanol extract of sesame (Sesamum indicum) seeds was fractionated and purified with the assistance of conventional column chromatography to afford 29 compounds including seven furofuran lignans. Among these isolates, (+)-samin (1) was obtained from the natural source for the first time. In addition, (-)-asarinin (30) and sesamol (31) were generated by oxidative derivation from (+)-sesamolin (2) and (+)-sesamin (3), two abundant lignans found in sesame seeds. To evaluate their in vitro antioxidant potential, the seven isolated lignans (1-7) and the two derivatives (30 and 31) were examined for the scavenging activities on DPPH free radicals and superoxide anions. Moreover, the capability of chelating ferrous ions and reducing power of these sesame lignans were also measured. The results suggest that, besides the well-known sesamolin and sesamin, the minor sesame lignans (+)-(7S,8'R,8R)-acuminatolide (5), (-)-piperitol (6), and (+)-pinoresinol (7) are also adequate active ingredients and may be potential sources for nutritional and pharmacological utilization.