Anthoceros angustus Steph. is rich in phenolic acids such as rosmarinic acid (RA). Phenylalanine ammonia-lyase (PAL) is an entry enzyme in the phenylpropanoid pathway of plants, playing an important role in the biosynthesis of RA. To investigate the important role of PAL in rosmarinic acid synthesis, two PAL genes (designated as AanPAL1 and AanPAL2) were cloned from A. angustus, encoding 755 and 753 amino acid residues, respectively. The AanPAL deduced amino acid sequences contain the conserved domains of PAL and the core active amino acid residues Ala-Ser-Gly. The phylogenetic analysis indicated that AanPAL1 and AanPAL2 were clustered with PALs from bryophytes and ferns and had the shortest evolutionary distance with the PALs from Physcomitrella patens. Quantitative real-time PCR results showed that the expression of AanPAL1 and AanPAL2 was induced by exogenous methyl jasmonate (MeJA). HPLC results showed that the MeJA treatment significantly increased the accumulation of RA. AanPAL1 and AanPAL2 were expressed in Escherichia coli and purified by histidine-tag affinity chromatography. The recombinant proteins catalyzed the conversion of L-phenylalanine to generate trans-cinnamic acid with high efficiency, with the best performance at 50 ℃ and pH 8.0. The K_m and k_cat of AanPAL1 were 0.062 mmol/L and 4.35 s^-1, and those of AanPAL2 were 0.198 mmol/L and 14.48 s^-1, respectively. The specific activities of AanPAL1 and AanPAL2 were 2.61 U/mg and 8.76 U/mg, respectively. The two enzymes had relatively poor thermostability but good pH stability. The high activity of AanPAL2 was further confirmed via whole-cell catalysis with recombinant E. coli, which could convert 1 g/L L-phenylalanine into trans-cinnamic acid with a yield of 100% within 10 h. These results give insights into the regulatory role of AanPAL in the biosynthesis of RA in A. angustus and provide candidate enzymes for the biosynthesis of cinnamic acid.
Phenylalanine Ammonia-Lyase/metabolism* ; Cloning, Molecular ; Cinnamates/metabolism* ; Recombinant Proteins/metabolism* ; Rosmarinic Acid ; Depsides/metabolism* ; Escherichia coli/metabolism* ; Amino Acid Sequence ; Plant Proteins/metabolism* ; Phylogeny ; Acetates/pharmacology* ; Cyclopentanes ; Oxylipins

By targeting the key gene csgD involved in the biofilm formation of Escherichia coli, we employed molecular docking and molecular dynamics simulation to screen the active components of Chinese medicine with inhibitory effects on the biofilm formation from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). After the anti-biofilm properties of the active components were validated in vitro, data-independent acquisition (DIA) proteomics was employed to further identify the differential proteins involved in interfering with the biofilm formation of Escherichia coli. The mechanisms of inhibition were explored with consideration to the phenotype. Through virtual screening, we identified four candidate active components, including tannic acid, narirutin, salvianolic acid B, and rosmarinic acid. Among them, tannic acid demonstrated significant inhibitory effect on the biofilm formation of E. coli. The analysis of differential proteins, combined with relevant phenotype validation, suggested that tannic acid primarily affected E. coli by intervening in pilus assembly, succinic acid metabolism, and the quorum sensing system. This study provided a lead compound for the development of new drugs against biofilm-associated infections in the future.
Biofilms/drug effects* ; Escherichia coli/metabolism* ; Molecular Docking Simulation ; Drugs, Chinese Herbal/chemistry* ; Tannins/chemistry* ; Cinnamates/metabolism* ; Benzofurans/chemistry* ; Depsides/metabolism* ; Rosmarinic Acid ; Anti-Bacterial Agents/chemistry* ; Escherichia coli Proteins/genetics* ; Medicine, Chinese Traditional

This study aims to establish a method for the simultaneous determination of 7 active components in Dracocephalum tanguticum and to evaluate the quality of medicinal materials from different habitats. The method was established with high performance liquid chromatography(HPLC) and the gradient elution was performed with the mobile phase of acetonitrile-methanol-0.2% phosphoric acid solution at a column temperature of 35 ℃, an injection volume of 15 μL, and a flow rate of 0.6 mL·min~(-1). The detection wavelength was set as 215 nm. With rosmarinic acid as the internal reference, the relative correction factors and the content of other 6 components were calculated. The results were compared with those obtained with the external standard method. The results showed that the samples from Huangzhong county, Qinghai province had the best quality, with the highest content of p-hydroxybenzoic acid, cosmosiin, rosmarinic acid, oleanolic acid, and ursolic acid(9.29, 12.14, 6.02, 3.11, 17.67 mg·g~(-1) respectively). The samples from Chaya county, Tibet autonomous region ranked the second, with the highest content of betulin and betulinic acid(15.53, 7.17 mg·g~(-1), respectively). The method is accurate, reliable, and repeatable and suitable for the simultaneous determination of multiple components in D. tanguticum. The content of functional components varied in the samples from different producing areas and can be used as the indicator for the quality evaluation of medicinal materials.
Cinnamates ; Drugs, Chinese Herbal/analysis* ; Lamiaceae ; Chromatography, High Pressure Liquid/methods* ; Rosmarinic Acid

Rosmarinic acid,a hydrosoluble polyphenolic hydroxyl compound,is the active ingredient in such traditional Chinese medicines as Menthae Haplocalycis Herba,Salviae Miltiorrhizae Radix et Rhizoma,Rosemary,Perillae Folium. Because of its good anti-inflammatory,anti-oxidant and anti-tumor effects,it is widely used in food,medicine and other fields. However,the metabolic process and metabolites of rosmarinic acid in vivo have not been completely defined. In this study,an efficient method of ultra-high performance liquid chromatography combined with linear ion trap-Orbitrap(UHPLC-LTQ-Orbitrap) mass spectrometer was used to analyze the metabolites in vivo of rosmarinic acid in rats. Plasma,urine and feces samples were collected after oral administration of rosmarinic acid. After biological samples were processed by solid phase extraction,Acquity UPLC  BEH C18 column(2. 1 mm × 100 mm,1. 7 μm) was used with 0. 1% formic acid(A)-acetonitrile(B) solution as the mobile phase at the speed of 0. 30 m L·min-1 and temperature of 35 ℃ under gradient conditions. The plasma,urine,feces and the blank samples were then analyzed by ESI-LTQ-Orbitrap under both negative and positive ion modes. Based on the accurate mass measurement(<5),MS/MS fragmentation patterns,standards and literatures,a total of 36 metabolites were screened out and identified in the biological samples collected from rats after intragastric administration. Three were identified 3 from rat plasma,31 from urine,and 7 from feces. The main metabolic pathways of rosmarinic acid in rats can be divided into five parts. Rosmarinic acid were first decomposed into small molecules,such as trans-caffeic acid,coumaric acid,m-hydroxybenzoic acid and Danshensu,which were followed by sulfation,methylation,glucuronic acid conjugation and glucose conjugation. The results showed that UHPLC-LTQ-Orbitrap mass spectrometer could be used to analyze the metabolism of rosmarinic acid in rats,and provide reference for further studies on toxicology,pharmacodynamics and secondary development of Chinese medicine.
Animals ; Chromatography, High Pressure Liquid ; Cinnamates/metabolism* ; Depsides/metabolism* ; Drugs, Chinese Herbal/metabolism* ; Rats ; Tandem Mass Spectrometry ; Rosmarinic Acid