The phytochemical investigation of the ethyl acetate fraction of 95% ethanol extract of Dendrobium nobile led to the isolation of two previously unreported compounds by various column chromatography methods, including silica gel, MCI, Toyopearl HW-40C combined with the semi-preparative HPLC. Their structures were determined by HRESIMS, NMR, IR, and UV, and identified as neodendronbibisline A (1), neodendronside A (2). Furthermore, compound 1 is a new phenanthrene with a benzofuran structural unit, and compound 2 is a new phenylpropanin glycoside.

The chemical constituents of the soft coral Sinularia sp. collected off Ximao Island in the South China Sea were isolated by comprehensively utilizing various separation techniques such as thin-layer chromatography, silica gel column chromatography, octadecylsilane reverse phase column chromatography, Sephadex LH-20 column chromatography, and high-performance liquid chromatography (HPLC). The planar structure and stereochemistry of the isolated compounds were determined by nuclear magnetic resonance (NMR), mass spectrometry (MS), infrared spectroscopy (IR), and quantum chemical calculations. Six compounds were isolated from the titled soft coral and identified as (3R, 6S)-3-((R)-sec-butyl)-6-isopropylmorpholine-2, 5-dione (1), oculatolide (2), octahydro-4-hydroxy-3R-methyl-7-methylene-R-(1-methylethyl)-1H-indene-1-methanol (3), ent-4(15)-eudesmene-1β, 6α-diol (4), 5-epi-eudesm-4(15)-ene-1β, 6β-diol (5), and ergosterol peroxide (6), respectively. Among them, compound 1 was characterized as a new morpholine derivative, and compounds 3-5 were isolated for the first time from this genus of soft corals. In terms of biological activity, compounds 1-6 underwent screening for antibacterial, anti-inflammatory, and anti-cancer activities, compounds 2 and 6 exhibited significant and broad-spectrum antimicrobial activity, while compound 2 also showed potent anti-inflammatory (IC₅₀ = 5 ± 0.03 mmol·L^-1) and strong anti-proliferative activity against human non-small cell lung cancer cells (A549) and human colorectal adenocarcinoma cells (HT-29) with IC₅₀ values of 17.27 ± 2.32 and 14.14 ± 0.72 mmol·L^-1, respectively.

Employing modern chromatographic techniques, including silica gel, gel chromatography, and semi-preparative liquid chromatography, the chemical constituents from the aerial parts of Salvia hispanica L. were isolated and purified. The structures of the obtained compounds were elucidated by means of contemporary spectroscopic methods. Three neo-clerodane diterpenoids were isolated and identified as 10-deoxyhispanin J (1), ent-(5R, 9R)-15, 16-epoxy-10S-hydroxycleroda-3, 13(16), 14-triene-17, 12S; 18, 19-diolide (2), and dehydrokerlin (3). Among them, compound 1 was a new diterpenoid, and compounds 2 and 3 were isolated from this plant for the first time. The lipid-lowering activity of compound 1 was evaluated in vitro using an oleic acid-induced high-lipid model in HL7702 cells. The results demonstrated that, compared with the positive control curcumin, compound 1 inhibited intracellular lipid accumulation and reduced triglyceride levels, indicating its potential as a lipid-lowering agent.

Three limonoids were isolated and purified from the 95%, 85% ethanol extracts of Melia azedarach using silica gel column chromatography, Sephadex LH-20 column chromatography, MCI column chromatography, and preparative RP-HPLC. Their structures were determined based on physicochemical properties and spectral data, and they were identified as 29-O-ethyl neoazedarachin D (1), 29-O-meliarachin G (2), toosendanin (3). Compound 1 is a new limonoid, while compound 2 is a new natural product isolated from plants for the first time. The in vitro anti-hepatocarcinoma activities of compounds 1-3 were evaluated by MTT assay. The results showed that compounds 1-3 exhibited different degrees of inhibitory effects on both HepG-2 and Hep3B cell lines, and the inhibitory effect of compound 3 on HepG-2 cells was comparable to that of the positive drug cisplatin. In addition, compounds 1-3 exhibited IC₅₀ values of 38.67 ± 1.336, 28.21 ± 1.028 and 8.21 ± 1.231 μg·mL^-1 against HepG-2 cells, and 47.36 ± 1.008, 35.69 ± 1.217 and 15.10 ± 1.017 μg·mL^-1 against Hep3B cells, respectively.

The study aimed to establish a HPLC method and a two-dimensional liquid chromatography-quadrupole time-of-flight mass spectrometry (2D-LC-Q-TOF/MS) method for the determination of the related substances degradated by tryptophan in pediatric compound amino acid injection and the exploration of the degradation pathway of tryptophan. The HPLC method was carried out on a Waters Atlantis T3 C18 (250 mm × 4.6 mm, 5 μm) column by gradient elution using phosphate buffer solution-acetonitrile (990∶12) and phosphate buffer solution-acetonitrile (65∶35) as the mobile phases to separate tryptophan and the related substances degradated by tryptophan. The selected components were then trapped in switch valve tube lines respectively and delivered to the second-dimensional desalting and deacidification gradient elution which was performed with an Agilent ZORBAX Eclipse Plus C18 (50 mm × 3.0 mm, 1.8 μm) column using acetonitrile-water (95∶5) as the mobile phases. The positive ion mode of the electrospray ionization source was adopted, the parent ions were detected using MS scan mode and the fragment ions were detected using targeted MS/MS mode. The structure of the unknown impurities was figured out by mass spectrometry elucidation. The results showed that tryptophan and its related substances in pediatric compound amino acid injection can be adequately separated under the established analytical conditions. A new impurity produced by the interaction between tryptophan and antioxidant excipients such as sodium bisulfite or sodium metabisulfite was discovered for the first time. The method can provide reference for the quality control of this injection.

Deer antler, a valued traditional Chinese medicine, faces persistent challenges in quality control due to the complex species origins, prevalent adulteration practices, and the absence of specific quantitative standards. To address this challenge, a proteomics strategy was employed to screen signature peptides from deer antlers and reindeer antlers in our pevious study. Combining the reported antler peptides from Cervidae, a comprehensive specificity revalidation was conducted. Finally, six deer antler signature peptides were identified as quality control (QC) markers for quantitative analysis, while reindeer, cow, sheep, and pig-specific peptides were determined as markers for adulteration inspection. Based on these QC markers, an ultrasonic-assisted enzymatic digestion method that completed sample preparation within 6 hours was developed in this study, significantly enhancing analytical efficiency. A UHPLC-MS/MS was utilized for establishment of absolute quantification and adulteration inspection method for deer antlers. The results indictated the validated methods showed high sensitivity and specificity, meeting all requirements for methodological requirements. The proposed method was subsequently applied to 56 commercially available samples (including 28 batches of deer antler slices and 28 batches of deer antler powder). The results revealed that 17.9% for slices and 10.7% for powder were deemed authentic and unadulterated. The total detection rate for the ingredients of reindeer was 73.2% and some samples were found to contain cattle-derived ingredient, indicating the rampant chaos in the deer antler market. This study provided a comprehensive and reliable technical approach to address the aforementioned challenges and achieve quality control for deer antler and its related preparations. The summarized strategy for screening species-spcific peptides and developing quality control methods would provide significant references on the study of quality standards for animal-derived traditional Chinese medicines.

During the development and analysis of low-concentration epinephrine injections, two unreported trace impurities (impurity H and impurity M) have been newly identified. Their analysis and identification were particularly difficult due to their low content, poor stability, and difficult separation in some cases. For impurity H with short retentiontime, poor separation, low content and poor stability, a two-dimensional liquid chromatography-tandem mass spectrometry (2DLC-MS/MS) with column switching technique was employed. This enabled on-line separation, desalination and structure characterization. In contrast, impurity M which exhibits better separability and stability, was isolated and prepared through enrichment and concentration processes. Its structure was then identified using techniques such as liquid chromatography-high resolution mass spectrometry (LC-HRMS) and NMR, enabling the acquisition of more comprehensive structural information. Experimental results showed that impurity H achieved effective separation in the first-dimensional chromatography and successful on-line desalination and fraction cutting in the second-dimensional chromatography. Its potential chemical structure was deduced through multi-stage mass spectrometry data analysis. For impurity M, efficient enrichment and concentration were accomplished; its structure was further confirmed by combining molecular weight and fragment information from LC-HRMS with spectral data from NMR. This study compared the performance of 2DLC-MS/MS with column switching technology with the traditional impurity concentration and identification technology. The experimental results not only provide a valuable strategy for analyzing and identifying trace impurities in complex matrix samples, but also offer an effective analytical tool for the quality control of trace impurities in low concentration epinephrine injections.

Polymer-drug conjugates have shown great potential in the field of drug delivery, but existing systemic pharmacokinetic data are difficult to clarify their pharmacokinetic behavior at the cellular level. In this study, multi-loaded pegylated irinotecan conjugate (PEG-[irinotecan]₃) was used as a model drug to build a research idea based on the interaction of polymorphic components to analyze its cellular pharmacokinetics. An HPLC-MS/MS analysis method based on in-source collision-induced dissociation (IS-CID) technology was established to achieve accurate quantitative analysis of PEG-[irinotecan]₃ and its intracellular polymorphic components, and comprehensively clarify its intracellular uptake, efflux and subcellular distribution characteristics. Uptake studies have shown the presence of polymorphic components in cells such as bonded drugs (PEG-[irinotecan]_{x (x = 3, 2, 1)}), release material (PEG20K), free drug (irinotecan) and active metabolite (SN-38). Subcellular distribution studies have shown that bonded drugs and release materials are mainly distributed in the cytoplasm, while irinotecan is mainly distributed in the cytoplasm and nucleus. This study expands the cellular pharmacokinetic research system of polymer-drug conjugates, and the key information obtained is of great value in guiding drug design, clarifying intracellular pharmacokinetic behavior, and promoting clinical transformation.

Dipeptidyl peptidase 4 (DPP4) is a serine protease widely present in human body, which can specifically catalyze the hydrolysis of proline (Pro) or alanine (Ala) peptide bond at the second N-terminal position of polypeptide chain. It is involved in the activation, partial or complete inactivation of a variety of bioactive polypeptides in vivo. In this study, the kinetic parameters of different probe substrates GP-PNA, GP-AMC and GP-BAN catalyzation by DPP4 were compared, and the inhibitory kinetic differences between DPP4 and its inhibitor sitagliptin/vildagliptin under different probe systems were studied. By means of molecular docking technology, the interaction mechanism between DPP4 and different substrates was revealed from the perspective of small molecules, and the key factors affecting the activity of DPP4 catalytic substrates were discussed. The results show that DPP4 has the best binding property to probe GP-BAN, and its affinity is higher than that of GP-AMC and GP-PNA, which proves that the carbon structure of probe is the key factor affecting the binding. Sitagliptin has better inhibitory activity on DPP4 than vildagliptin. The molecular docking results suggest that the halogenation characteristic of sitagliptin may be the key factor to enhance its binding ability. This study can provide an important basis for the selection of DPP4 probes under different research purposes, and also provide experimental data and research basis for rational design and development of highly selective DPP4 ligand tool molecules and personalized rational drug use in clinic.

In the study, bifunctional tanshinone IIA nanoparticles (Tan IIA/M-NPs) with both mannose targeting and reactive oxygen species response were prepared by nanoprecipitation using methoxypoly (ethylene glycol)-disulfide bond-poly (lactic acid hydroxyacetic acid) copolymer (mPEG_5k-SS-PLGA_60k) and phospholipid poly (ethylene glycol) mannan (DSPE-PEG_5k-Man) as the carriers, and tanshinone IIA (Tan IIA) as the model drug. The preferred process parameters were obtained through one-way experiments, and the optimal conditions were determined as follows: a drug-to-carrier mass ratio of 1∶12, an oil-to-water volume ratio of 1∶10, a peloxam concentration of 2.0%, a sonication time of 12 min, and a targeting material modification ratio of 10%. the average particle size of Tan IIA/M-NPs was 198.3 ± 2.8 nm, and the polydispersity coefficient. The average particle size of Tan IIA/M-NPs was 198.3 ± 2.8 nm, the polydispersity index (PDI) was 0.224 ± 0.002, the zeta potential was -2.62 ± 0.94 mV, and the encapsulation rate was (94.41 ± 0.36)%. The results of in vitro cellular experiments showed that Tan IIA concentration in the range of 0.1-100 µmol·L^-1, Tan IIA, blank vector and Tan IIA/M-NPs were all biocompatible with each other and had no significant toxicity to macrophages; the uptake efficiency of inflammatory macrophages by mannose-modified Tan IIA/M-NPs was significantly higher than that of the unmodified group; and Tan IIA/M-NPs significantly reduced the secretion level of macrophage inflammatory factors (TNF-α, IL-1β), inhibited NO production, decreased the proportion of M1-type macrophages, promoted the polarization of M2-type macrophages, and decreased the intracellular level of reactive oxygen species. Tan IIA/M-NPs had a good drug-carrying capacity, and could enhance the inhibitory effect of Tan IIA via mannose targeting and ROS-responsive release. The inhibitory effect on myocardial inflammation provides a new research idea for the regulation of inflammation and tissue repair after myocardial infarction treated with tanshinone IIA.