[Metabolite identification and metabolic pathway analysis of Platycodonis Radix extracts from Tongcheng city in rats].

In this study, we delved into the prototypical components and metabolites of Platycodonis Radix extracts(PRE) from Tongcheng city in plasma, urine and feces of rats, and revealed its metabolic pathways and metabolic rules in vivo. The prototypical components and metabolites of PRE in rats were characterized and identified by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS) and mass defect filter(MDF). The biological samples were analyzed by ACQUITY UPLC BEH C_(18)(2.1 mm×100 mm, 1.7 µm), with 0.1% formic acid water(A)-0.1% formic acid acetonitrile(B) as mobile phase, and the biological samples were analyzed in negative ion mode by electrospray ionization mass spectrometry(ESI-MS). Twelve prototypical saponins and twenty-seven metabolites were detected in plasma, urine and feces of rats treated with PRE by oral administration. Eleven prototypical components and nine metabolites were detected in plasma, eleven prototypical components and eight metabo-lites were detected in urine, and ten prototypical components and twenty metabolites were detected in feces. Further studies showed that the metabolic pathways of PRE in rats mainly include oxidation, reduction, acetylation, stepwise hydrolytic deglycosylation, glucuronidation and so on. This study provides a scientific basis for clarifying the pharmacological basis and mechanism of PRE from Tongcheng city.

Two new N-containing heterocyclic compounds from the roots of Platycodon grandiflorus.

Two unusual N-containing heterocyclic compounds, Plagranlines B-C, were isolated from the roots of Platycodon grandiflorus. Plagranline B (1) was consisted of neolignane and monomeric quinoline constituent units and plagranline C (2) possessed pyridinone ring that was not commonly discovered in natural product. Their planar structures were elucidated based on analysis of NMR and HRESIMS spectroscopy data, and their absolute configurations were determined by quantum chemical calculations, including GIAO 13C NMR (DP4+) calculation and ECD calculation. In addition, extensive activity screening including glycosidases, oestrogen-like, and NO inhibitory assays were performed, compounds 1 and 2 possessed the weak activities.

Sulfur-fluoride exchange (SuFEx)-enabled lead discovery of AChE inhibitors by fragment linking strategies.

SuFEx click chemistry has been a method for the rapid synthesis of functional molecules with desirable properties. Here, we demonstrated a workflow that allows for in situ synthesis of sulfonamide inhibitors based on SuFEx reaction for high-throughput testing of their cholinesterase activity. According to fragment-based drug discovery (FBDD), sulfonyl fluorides [R-SO2F] with moderate activity were identified as fragment hits, rapidly diversified into 102 analogs in SuFEx reactions, and the sulfonamides were directly screened to yield drug-like inhibitors with 70-fold higher potency (IC50 = 94 nM). Moreover, the improved molecule J8-A34 can ameliorate cognitive function in Aß1-42-induced mouse model. Since this SuFEx linkage reaction succeeds on picomole scale for direct screening, this methodology can accelerate the development of robust biological probes and drug candidates.

[Complete chloroplast genome sequencing and phylogeny of wild Atractylodes lancea from Yuexi, Anhui province].

This study investigated the choroplast genome sequence of wild Atractylodes lancea from Yuexi in Anhui province by high-throughput sequencing, followed by characterization of the genome structure, which laid a foundation for the species identification, analysis of genetic diversity, and resource conservation of A. lancea. To be specific, the total genomic DNA was extracted from the leaves of A. lancea with the improved CTAB method. The chloroplast genome of A. lancea was sequenced by the high-throughput sequencing technology, followed by assembling by metaSPAdes and annotation by CPGAVAS2. Bioiformatics methods were employed for the analysis of simple sequence repeats(SSRs), inverted repeat(IR) border, codon bias, and phylogeny. The results showed that the whole chloroplast genome of A. lancea was 153 178 bp, with an 84 226 bp large single copy(LSC) and a 18 658 bp small single copy(SSC) separated by a pair of IRs(25 147 bp). The genome had the GC content of 37.7% and 124 genes: 87 protein-coding genes, 8 rRNA genes, and 29 tRNA genes. It had 26 287 codons and encoded 20 amino acids. Phylogenetic analysis showed that Atractylodes species clustered into one clade and that A. lancea had close genetic relationship with A. koreana. This study established a method for sequencing the chloroplast genome of A. lancea and enriched the genetic resources of Compositae. The findings are expected to lay a foundation for species identification, analysis of genetic diversity, and resource conservation of A. lancea.

Novel benzothiazole‒urea hybrids: Design, synthesis and biological activity as potent anti-bacterial agents against MRSA.

Novel benzothiazole‒urea hybrids were designed, synthesized and evaluated their anti-bacterial activity. They only exhibited anti-bacterial activity against Gram-positive bacteria, including clinical methicillin-resistant S. aureus (MRSA), compounds 5f, 5i, 8e, 8k and 8l exhibited potent activity (MIC = 0.39 and 0.39/0.78 µM against SA and MRSA, respectively). Crystal violet assay showed that compounds 5f, 8e and 8l not only inhibited the formation of biofilms but also eradicated preformed biofilms. Compound 8l had membrane disruption, little propensity to induce resistance, benign safety and in vivo anti-MRSA efficacy in a mouse model of abdominal infection. Therefore, our data demonstrated the potential to advance benzothiazole‒urea hybrids as a new class of antibiotics.

Molecular cloning and functional characterization of an isoflavone glucosyltransferase from Pueraria thomsonii.

Pueraria thomsonii has long been used in traditional Chinese medicine. Isoflavonoids are the principle pharmacologically active components, which are primarily observed as glycosyl-conjugates and accumulate in P. thomsonii roots. However, the molecular mechanisms underlying the glycosylation processes in (iso)flavonoid biosynthesis have not been thoroughly elucidated. In the current study, an O-glucosyltransferase (PtUGT8) was identified in the medicinal plant P. thomsonii from RNA-seq database. Biochemical assays of the recombinant PtUGT8 showed that it was able to glycosylate chalcone (isoliquiritigenin) at the 4-OH position and glycosylate isoflavones (daidzein, formononetin, and genistein) at the 7-OH or 4'-OH position, exhibiting no enzyme activity to flavonones (liquiritigenin and narigenin) in vitro. The identification of PtUGT8 may provide a useful enzyme catalyst for efficient biotransformation of isoflavones and other natural products for food or pharmacological applications.

Antibacterial and anti-biofilm activity of diarylureas against Enterococcus faecium by suppressing the gene expression of peptidoglycan hydrolases and adherence.

Enterococcus faecium (E. faecium) is a clinical multidrug-resistant pathogen causing life-threatening infection, which makes it important to discover antibacterial agents with novel scaffolds and unique mechanism. In this study, the diarylurea scaffold was found to have potent antibacterial effect on E. faecium. Diarylurea ZJ-2 with benign drug-like property exhibited potent antibacterial and anti-biofilm activity through inhibiting the genes expression of NlpC/p60 hydrolase-secreted antigen A (sagA) and autolysins (atlA), down-regulating the expression of biofilm adherence related genes aggregation substance (agg), enterococcal surface protein (esp) against E. faecium. Moreover, ZJ-2 can be docked into SagA to inhibit daughter cell separation. In a mouse model of abdominal infection, ZJ-2 decreased the bacterial load and the level of IL-6 and TNF-α in a time-dependent manner. Overall, these findings indicated that diarylurea ZJ-2 has the potential to be developed as a therapeutic agent to treat drug-resistant enterococci and biofilm-related infections.

[Cloning and prokaryotic expression of 3-ketoacyl-CoA thiolase gene AIKAT from Atractylodes lancea].

In this study, the gene encoding the key enzyme 3-ketoacyl-CoA thiolase(KAT) in the fatty acid ß-oxidation pathway of Atractylodes lancea was cloned. Meanwhile, bioinformatics analysis, prokaryotic expression and gene expression analysis were carried out, which laid a foundation for the study of fatty acid ß-oxidation mechanism of A. lancea. The full-length sequence of the gene was cloned by RT-PCR with the specific primers designed according to the sequence information of KAT gene in the transcriptomic data of A. lancea and designated as AIKAT(GenBank accession number MW665111). The results showed that the open reading frame(ORF) of AIKAT was 1 323 bp, encoding 440 amino acid. The deduced protein had a theoretical molecular weight of 46 344.36 and an isoelectric point of 8.92. AIKAT was predicted to be a stable alkaline protein without transmembrane segment. The secondary structure of AIKAT was predicted to be mainly composed of α-helix. The tertiary structure of AIKAT protein was predicted by homology modeling method. Homologous alignment revealed that AIKAT shared high sequence identity with the KAT proteins(AaKAT2, CcKAT2, RgKAT and AtKAT, respectively) of Artemisia annua, Cynara cardunculus var. scolymus, Rehmannia glutinosa and Arabidopsis thaliana. The phylogenetic analysis showed that AIKAT clustered with CcKAT2, confirming the homology of 3-ketoacyl-CoA thiolase genes in Compositae. The prokaryotic expression vector pET-32 a-AIKAT was constructed and transformed into Escherichia coli BL21(DE3) for protein expression. The target protein was successfully expressed as a soluble protein of about 64 kDa. A real-time quantitative PCR analysis was performed to profile the AIKAT expression in different tissues of A. lancea. The results demonstrated that the expression level of AIKAT was the highest in rhizome, followed by that in leaves and stems. In this study, the full-length cDNA of AIKAT was cloned and expressed in E. coli BL21(DE3), and qRT-PCR showed the differential expression of this gene in different tissues, which laid a foundation for further research on the molecular mechanism of fatty acid ß-oxidation in A. lancea.

Novel cannabidiol-carbamate hybrids as selective BuChE inhibitors: Docking-based fragment reassembly for the development of potential therapeutic agents against Alzheimer's disease.

Cannabidiol (CBD) and rivastigmine have been launched as drugs for treating dementia and cholinesterases (ChEs) are ideal drug targets. This study focused on developing novel ChE inhibitors as drug leads against dementia through molecular modeling and fragment reassembly approaches. A potent carbamate fragment binding to active site gorge of BuChE was found via a docking-based structural splicing approach, thus, 17 novel compounds were designed by structural reassembly. Compound C16 was identified as a highly selective potent BuChE inhibitor (IC50 = 5.3 nM, SI > 4000), superior to CBD (IC50 = 0.67 µM). C16 possessed BBB penetrating ability, benign safety, neuroprotection, antioxidant and pseudo-irreversible BuChE inhibition (Kd = 13 nM, k2 = 0.26 min-1), showing good drug-like properties. In vivo studies confirmed that C16 significantly ameliorated the scopolamine-induced cognition impairment, almost entirely recovered the Aß1-42 (icv)-impaired cognitive function to the normal level, showed better behavioral performance than donepezil and good anti-amyloidogenic effect. Hence, the potential BuChE inhibitor C16 can be developed as a promising disease-modifying treatment of AD.

Design and synthesis of novel glycyrrhetin ureas as anti-inflammatory agents for the treatment of acute kidney injury.

To develop new anti-inflammatory drugs for the prevention and treatment of acute kidney injury, a series of novel glycyrrhetic ureas were designed, synthesized and evaluated for anti-inflammatory activity using RAW264.7 cells. Compounds 5r-5u (2.04, 2.50, 3.25 and 2.48 µM, respectively) with acidic or neutral amino acid showed potent anti-inflammatory activity (IC50 = 2-3 µM for NO inhibition), amongst them, compound 5r also inhibited tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in a dose-dependent manner. In cisplatin-induced AKI mice model, compound 5r significantly reduced the level of pro-inflammatory factors, ameliorated the pathological damage of kidney tissue, and maintained the normal metabolic capacity.

Correction: Yu, D.Q., et al. Microscopic Characteristic and Chemical Composition Analysis of Three Medicinal Plants and Surface Frosts. Molecules 2019, 24, 4548.

The authors would like to correct an error in the title paper [...].

Free-standing 2D non-van der Waals antiferromagnetic hexagonal FeSe semiconductor: halide-assisted chemical synthesis and Fe2+ related magnetic transitions.

The scarcity of two-dimensional (2D) magnetic nanostructures has hindered their applications in spintronics, which is attributed to that most magnetic materials exhibit non-van der Waals (nvdWs) structures and it is hard to reduce their thickness to 2D nanostructures. Thus it is necessary to develop a promising strategy for free-standing 2D magnetic nvdWs nanostructures. We have achieved free-standing 2D nvdWs hexagonal FeSe with a thickness of 2.9 nm by the reaction between the oleylamine-Se complex and Fe2+ with the assistance of Cl-, where the synergetic effects of Cl- and -NH2 lead to anisotropic growth. Inspiringly, the 2D hexagonal FeSe exhibits intrinsic antiferromagnetic order rooted in Fe2+ and semiconducting nature. In addition, the temperature variation would result in the chemical environment changes of Fe2+, responsible for the temperature-dependent magnetic transitions. This work promotes the potential applications of 2D hexagonal FeSe and the preparation of other 2D nvdWs materials.

Gate-tunable high magnetoresistance in monolayer Fe3GeTe2 spin valves.

Ferromagnetic order in two-dimensional (2D) van der Waals crystals has been attracting much attention recently. Remarkably, room temperature metallic ferromagnetism is realized in 2D Fe3GeTe2. Here we design a monolayer (ML) Fe3GeTe2 spin-valve device by attaching two ends to ferromagnetic electrodes and applying a magnetic field to these ferromagnetic electrodes. We investigate the spin-involved transport characteristics of such a spin valve by using ab initio quantum transport simulation. A high magnetoresistance of ∼390% is obtained and significantly increased to 450-510% after the gates are introduced. The magnetoresistance of the ML Fe3GeTe2 spin valve is insensitive to the strain modulation. Our study provides a potential option for magnetic storage applications and will motivate further studies in spintronics based on this class of materials.

[Cloning and prokaryotic expression analysis of squalene synthase CpSQS1 and CpSQS2 from Crataegus pinnatifida].

In order to understand the structural characteristics of squalene synthase genes in the triterpenoids biosynthesis pathway of Crataegus pinnatifida, the squalene synthase genes of C. pinnatifida was cloned and analyzed by bioinformatics and prokaryotic expression. Two squalene synthase genes CpSQS1 and CpSQS2 were cloned from C. pinnatifida fruit by RT-PCR. The ORF length of CpSQS1 and CpSQS2 were 1 239 bp and 1 233 bp respectively, encoding 412 aa and 410 aa respectively. CpSQS1 and CpSQS2 were predicted to be stable acidic proteins by online tools. The secondary structure was mainly composed of α-helix structure, and the tertiary structure was predicted by homology modeling. Structural functional domain analysis showed that 35-367 aa of CpSQS1 and CpSQS2 cDNA containing conserved trans-isoprenyl pyrophosphate synthase domains. Transmembrane domain analysis predicted that two transmembrane domains were founded in CpSQS1 and CpSQS2. The squalene synthase amino sequence of C. pinnatifida had higher homology with the known SQS of Salvia miltiorrhiza and Glycyrrhiza glabra. Phylogenetic tree analysis showed that CpSQS1 and CpSQS2 were clustered into one branch of MdSQS1 and MdSQS2, which were consistent with the phylogenetic rule. Prokaryotic expression vector pGEX-4 T-1-CpSQS1 and pGEX-4 T-1-CpSQS2 were transformed into Escherichia coli Transetta(DE3) for induction, and the target protein was successfully expressed at 65 kDa. The expression levels of CpSQS2 were significantly higher than that of CpSQS1 in three different developmental stages of C. pinnatifida. In this study, the full-length cDNA sequences of C. pinnatifida SQS1 and SQS2 were cloned and analyzed for the first time, which provided the foundation for further study on the metabolic pathway of C. pinnatifida triterpenoids.

[Comparative study on appearance characters and internal structure of cultivated and wild Ganoderma lucidum in Huoshan].

Through the comparative study on the appearance characters and internal structure of cultivated and wild Ganoderma lucidum in Huoshan,this paper provides a reference for the further study of G. lucidum. In this study,the similarities and differences between cultivated G. lucidum " Huozhi No. 1" and wild G. lucidum in Huoshan were compared by means of character observation,optical microscopy and scanning electron microscope( SEM). The results showed that the pileus color of " Huozhi No. 1" was yellowish brown and thicker,while that of wild G. lucidum was mainly reddish brown,the context was thinner,and there were gravel and rotten wood at the bottom of the stipe. A clear skeletal hyphae and binding hyphae were observed in cultivated and wild G. lucidum,but there was no significant difference. The shell layer,context layer,mediostratum layer and spores of cultivated and wild G. lucidum were observed by SEM,and the results showed that there was no significant difference. It was found that the mediostratum of " Huozhi No. 1" was thin and irregular,while the mediostratum of wild G. lucidum was neat and compact. There were two types of spores in wild G. lucidum,one of which retained the outer wall of spore type Ⅰ,with tiny pores on the surface. The other is type Ⅱ spores with many spinous processes on the surface,which may be formed by type Ⅰ spores falling off the outwall. In this study,the appearance characters and internal structure of cultivated and wild G. lucidum in Huoshan were systematically observed and compared,which provided theoretical basis and reference for the identification and quality evaluation of cultivated and wild G. lucidum.

Microscopic Characteristic and Chemical Composition Analysis of Three Medicinal Plants and Surface Frosts.

The accumulation of chemical constituents of some medicinal plants, such as Paeonia ostii T. Hong et J. X. Zhang, Houpoëa officinalis (Rehder and E. H. Wilson) N. H. Xia and C. Y. Wu. and Atractylodes lancea (Thunb.) DC, can precipitate on the surface and form frosts after natural or artificial intervention. The characteristics of these three medicinal plants and their frosts were analyzed by light microscope, polarizing microscope, stereomicroscope, and metalloscope. The results of ordinary Raman of P. ostii and H. officinalis showed that the frosts of P. ostii matched paeonol, while that of H. officinalis matched magnolol and honokiol. In P. ostii and its frost, 19 peaks were identified by UPLC-Q/TOF-MS, and the main component was paeonol. Eleven components were identified in H. officinalis and its frosts, and the main components were magnolol and honokiol. A. lancea and its frosts were analyzed by gas chromatography-mass spectrometry (GC-MS), 21 were identified, and its main components were hinesol and ß-eudesmol. These three medicinal plants accumulate compounds and precipitate frosts on the surface. The results show that the components of the frosts provide a basis for quality evaluation and research on similar medicinal plants, and reveals the scientific connotation of "taking the medicinal materials' precipitated frosts as the best" of P. ostii, H. officinalis, and A. lancea, to some extent.

[Identification of Corydalis yanhusuo,C. turtschaninovii,C. decumbens by allele-specific PCR].

To establish a DNA molecular markers method for identification of Corydalis yanhusuo,C. turtschaninovii and C. decumbens,the mat K,trn G and psb A-trn H sequences of 56 samples from 14 species of C. yanhusuo,C. turtschaninovii,C. decumbens and their related species were obtained by sequencing. The SNP loci were obtained by Bio Edit 7. 2. 2 software. The primers for AS-PCR identification were designed based on the mutation sites,and the conditions of PCR were optimized to identify C. yanhusuo,C. turtschaninovii,and C. decumbens according to the specific bands. The results showed that the amount of template( 0. 6-1 200 ng)and annealing temperature( 42-60 ℃) had little influence on the amplification results,and the number of cycles had much influence on the amplification results. When the number of cycles was 20,the specific bands of 297 bp( mat K),353 bp( trn G) and 544 bp( mat K) were amplified from C. yanhusuo,C. turtschaninovii and C. decumbens,respectively. The method established in this study had a minimum detection limit of 6 ng for C. yanhusuo,60 ng for C. decumbens and less than 0. 6 ng for C. turtschaninovii. Thus,the allelespecific PCR method established in the research can specifically identify C. yanhusuo,C. turtschaninovii,and C. decumbens.

Determination of the species status of Fallopia multiflora, Fallopia multiflora var. angulata and Fallopia multiflora var. ciliinervis based on morphology, molecular phylogeny, and chemical analysis.

Relationships among Fallopia multiflora (Thunb.) Haraldson., F. multiflora var. angulata (S. Y. Liu) H. J. Yan, Z. J. Fang & Shi Xiao Yu., and F. multiflora var. ciliinervis (Nakai) Yonekura & H. Ohashi. were determined based on macroscopic and microscopic morphology, molecular phylogeny, and chemical analysis. The macroscopic and microscopic morphologies of root tubers or rhizomes, stems, and leaves were compared among the three taxa. The content of 11 chemical components (catechin, polydatin, stilbene glucoside, emodin, emodin-8-O-ß-D-glucopyranoside, rhein, chrysophanol, aloe-emodin, quercetin, physcion, and resveratrol) in the three taxa was determined by HPLC, and the chemical diversity was further evaluated by principal component and hierarchical cluster analyses. Molecular phylogenies were mapped using two chloroplast markers (matK and the psbA-trnH intergenic region) and a nuclear ribosomal marker [internal transcribed spacer 2 (ITS2) region]. Analyses of macroscopic and microscopic morphological characteristics revealed that the subterranean organs of F. multiflora and F. multiflora var. angulata are root tubers, whereas those of F. multiflora var. ciliinervis are rhizomes. In the phylogenetic trees, F. multiflora and F. multiflora var. angulata were clustered into a clade based on the combine matK + psbA-trnH sequence, with neighbour-joining, maximum likelihood, and Bayesian inference bootstrap support values of 99, 85, and 0.99, respectively. In addition, there were obvious differences in the chemical compositions of F. multiflora, F. multiflora var. angulata and F. multiflora var. ciliinervis. The root tubers of F. multiflora contain higher levels of stilbene glucoside and catechin, but lower levels of polydatin and anthraquinone compounds. In contrast to F. multiflora, the rhizomes of F. multiflora var. ciliinervis contain higher levels of polydatin and anthraquinone compounds, but lack stilbene glucoside. The content of all 11 assessed components was lower in F. multiflora var. angulata than in F. multiflora and F. multiflora var. cillinervis. Principal component and hierarchical cluster analyses revealed that F. multiflora and F. multiflora var. angulata individuals were clustered into a single clade, whereas F. multiflora var. ciliinervis individuals were clustered into a single clade separate from that containing F. multiflora and F. multiflora var. angulata individuals. On the basis of the results of our morphological, molecular phylogeny, and chemical analyses, we tentatively conclude that F. multiflora var. ciliinervis is an independent species, whereas F. multiflora var. angulata should be considered as a variety of F. multiflora.

[Species and medical history of "Xishuang" medicinal materials].

"Xishuang" is a special phenomenon that chemical composition of medicinal materials crystallize on the surface exposed to air for a long time. We summarized Herbal textual research of "Xishuang" phenomenon of six herbs, such as Schisandrae Chinensis Fructus, Moutan Cortex, Atractylodis Rhizoma, Magnoliae Officinalis Cortex, dried persimmon frost and watermelon frost. From historical perspective, cream of Schisandrae Chinensis Fructus was firstly discovered in Lei Gong's Moxibustion Theory. Thereafter, dried persimmon frost was found in Song Dynasty, which was named "white persimmon" in Ben Cao Tu Jing and had become an independent medicine in Compendium of Materia Medica. Then, watermelon frost was found in Yang Yi Da Quan of the Qing Dynasty, and Moutan Cortex's "sand star" was recorded in Zeng Ding Wei Yao Tiao Bian of the Republic of China. After that, "Xishuang" phenomenon of Atractylodis Rhizomaand Magnoliae Officinalis Cortex were reported in 1950s and 1960s in succession. The pattern of "Xishuang" is divided into different type, natural "Xishuang" includes Schisandrae Chinensis Fructus, Moutan Cortex, Atractylodis Rhizoma and Magnoliae Officinalis Cortex, artificial "Xishuang" includes watermelon frost, and dried persimmon frost formed crystals by using artificial intervention. The above 6 kinds of herbs have different crystal structure and chemical composition. Therefore, according to traditional identification experience, "Xishuang" phenomenon is related to varieties and quality of medicinal herbs. These research provide herbalism basis for the modern study of "Xishuang" medicinal materials.

[Growth rings in roots of seven Sect. Paeonia species and its application on identification of Paeoniae Radix Rubra].

The growth years of medicinal materials are closely related to their quality, and "Herb-chronology" has been used to determine the growth years of perennial dicotyledonous plants in recent years. On the basis of conventional paraffin section and freehand section, the anatomical study on roots of seven Sect. Paeonia species and main roots of cultivated Paeonia lactiflora was conducted in this paper. The results showed that, there existed some differences in microstructure of the seven species such as P. lactiflora, P. obovata, P. veitchii, P. mairei, P. anomala, P. sinjiangensis and P. anomala var. intermedia, and this could be used to distinguish different species. In the roots of seven Sect. Paeonia species, distinct growth rings were formed because that the different diameters or density of xylem vessels in the secondary xylem formed clusters and arranged interrupted rings in tangential direction. There were growth rings in the main roots of P. lactiflora cultivated 1-4 years in Siping, Jilin, which were all consistent with their growth years. Due to the similar growth characteristics between wild Sect. Paeonia species and cultivated P. lactiflora, the growth rings can provide a basis for the age identification and lay the foundation for the quality evaluation of Paeoniae Radix Rubra.