Characterization of polymeric phenolic acids and flavonoids in Clerodendranthi Spicati Herba using ultrahigh-performance liquid chromatography coupled to quadrupole time-of-flight tandem mass spectrometry with target and nontarget data mining strategy

Isolation and identification of endophytic fungi from Alhagi sparsifolia Shap. and their antibacterial activity

In order to explore the endophytic resources of Alhagi sparsifolia Shap. and identified novel antibacterial substances. Thirty endophytic fungal strains were isolated from the stems and roots of A. sparsifolia Shap. Morphological and molecular biology methods were used to identify ten strains of fungi, including four strains of Aspergillus niger, three strains of Alternaria alternata, two strains of Aspergillus flavus, and one strain of Fusarium incarnatum. All these strains were isolated from A. sparsifolia Shap. for the first time, and of these Aspergillus was the dominant genus. Antibacterial activity of the ten strains against Escherichia coli, Staphylococcus aureus, Candida albicans, and Pseudomonas aeruginosa were evaluated using the disc diffusion method. The results demonstrated that the metabolites from all the strains had inhibitory effects on at least one indicator bacterium. Notably, the endophytic fungi AFJ3 and AFG6 demonstrated strong broad-spectrum antibacterial activity, particularly against E. coli, with inhibition zones measuring 32.0 ± 0.3 and 31.3 ± 0.3 mm, respectively. The three endophytic fungi (AFG1, AFG2, and AFG3) isolated from the roots demonstrated significant antibacterial activity against P. aeruginosa forming an inhibition zone of diameter 31.3 ± 0.1, 25.6 ± 0.2, and 25.6 ± 0.2 mm, respectively. However, the strains of endophytic fungi demonstrated no significant inhibitory effects on C. albicans. Ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry/mass spectrometry (UPLC-QTOF-MS/MS) analysis depicted that the ethyl acetate phase of AFJ3 and AFG6 fermentation broth predominantly contained organic acids, phenolic acids, flavonoids, and fatty acids. These secondary metabolites often exhibited good antibacterial activity. This study broadens our understanding of endophytic fungi in A. sparsifolia Shap. The antibacterial activity of some strains of endophytic fungi was significant, making it worthy of further research on their active material.

Steam explosion-assisted grinding improves the functional properties and antioxidant activity of Java tea-leaf powders (Clerodendranthus spicatus)

BACKGROUND

Java tea is widely consumed and has multiple health effects. This study established a steam explosion (SE) pretreatment method to prepare Java tea-leaf powders. The physicochemical, functional properties, phenolic extraction, and antioxidant activity of Java tea-leaf powders produced by simple and SE-assisted milling methods were investigated.

RESULTS

In comparison with simple milling, SE pretreatment broke the cell wall effectively and reduced the particle size of Java tea-leaf powders. Steam explosion-treated powders showed higher values for sensory signals, bulk and tap density, and for the water solubility index. After SE treatment, the adsorption capacities to glucose, soybean oil, and cholesterol of leaf powders were increased by up to 55, 95, and 80% respectively. The extracts from SE-treated powders also showed higher total polyphenol content and antioxidant activity.

CONCLUSION

Steam explosion treatment is helpful for the improvement of functional properties and antioxidant activity, which can benefit the development and application of Java tea-leaf powders. © 2024 Society of Chemical Industry.

Physical properties, phenolic profile and antioxidant capacity of Java tea (Clerodendranthus spicatus) stems as affected by steam explosion treatment

Java tea (Clerodendranthus spicatus) has been favored for its various health benefits and abundance of phenolic substances. Steam explosion (SE) treatment was performed in the pretreatment of Java tea stems and the physical properties, phenolic profile and antioxidant capacity were investigated. Extraction kinetics study showed that the phenolics yields of Java tea stems treated at 2.4 MPa for 10 min reached the maximum in 40 min, which was approximately 3 times the yields of raw stems in 180 min. The antioxidant activities of the extracts of Java tea stems were also significantly increased after SE treatment (P < 0.05). In addition, 19 phenolics were detected in Java tea stems by HPLC/QTOF-MS/MS, and rosmarinic acid was found to be hydrolyzed to danshensu during the SE process. SE could be an efficient pretreatment technology to improve the extraction rates of phenolics and conversions of their high-value hydrolyzed products, which could facilitate further research of Java tea products.

Phytochemical analysis for ten Peruvian Mentheae (Lamiaceae) by liquid chromatography associated with high resolution mass spectrometry

The profile of secondary metabolites in ten members of tribe Mentheae (Nepetoideae, Lamiaceae) from Peru by liquid chromatography associated with high resolution mass spectrometry, is presented. Salvianolic acids and their precursors were found, particularly rosmarinic acid, caffeic acid ester derivatives, as well as a diversity of free and glycosylated flavonoids as main substances. At all, 111 structures were tentatively identified.

Screening of potent α-glucosidase inhibitory and antioxidant polyphenols in Prunella vulgaris L. by bioreaction-HPLC-quadrupole-time-of-flight-MS/MS and in silico analysis

Prunella vulgaris L. is a well-known traditional Chinese medicine for blood glucose homeostasis and antioxidant potential. Ethyl acetate fraction of P. vulgaris L. demonstrated higher phenolic content (85.53 ± 6.74 mg gallic acid equivalents per gram dry weight), α-glucosidase inhibitory (IC₅₀ , 69.13 ± 2.86 μg/mL), and antioxidant (IC₅₀ , 8.68 ± 1.01 μg/mL) activities. However, the bioactive polyphenols responsible for the beneficial properties remain unclear. Here, bioreaction-HPLC-quadrupole-time-of-flight-MS/MS method was developed for rapid, accurate, and efficient screening and identification of polyphenols with α-glucosidase inhibitory and antioxidant activities from P. vulgaris L. Bioactive polyphenols can specifically bind with α-glucosidase or react with 1,1-diphenyl-2-picryl-hydrazyl radical, which was easily discriminated from nonactive compounds. Subsequently, twenty bioactive polyphenols (sixteen phenyl propionic acid derivatives and four flavonoids) were screened and identified. Furthermore, molecular docking analysis revealed that screened twenty polyphenols bind with the active sites of α-glucosidase through hydrogen bonding and π-π stacking. Density functional theory calculations demonstrated their electron transport ability and chemical reactivity. The in silico analysis confirmed the screened results. In summary, this study provided a valuable strategy for rapid discovering bioactive compounds from complex natural products, and offered scientific evidence for further development and application of P. vulgaris L. This article is protected by copyright. All rights reserved.

Rapid identification of chemical constituents in Yinqiao Powder using ultra-high-performance liquid chromatography coupled to quadrupole-time-of-flight tandem mass spectrometry with data filtering strategy

Yinqiao Powder is a classic and effective prescription for the treatment of many kinds of pneumonia in China. To date, the chemical constituents had not been uncovered. Comprehensive identification of chemical constituents provided a structure basis to discover the potential anti-pneumonia ingredients in Yinqiao Powder. In this paper, ultra-high performance liquid chromatography coupled to quadrupole time of flight tandem mass spectrometry (UHPLC-QTOF-MS/MS) analysis with diagnostic product ions and neutral loss filtering strategy were established and applied for the comprehensive chemical profiling of Yinqiao Powder, which simplified structure elucidation of chemical constituents in Yinqiao Powder. A total of 124 compounds, including 8 C6-C2 glucoside conjugates, 28 iridoid glycosides, 14 lignans, 21 phenylethanol glycosides, 20 triterpenoid saponins, 9 chlorogenic acids and 24 flavonoids were rapidly identified in Yinqiao Powder, and 32 of them were characterized by comparing their MS/MS data and retention time with reference standards. The results indicated that UHPLC-QTOF-MS/MS method coupled with data filtering strategy was feasible and rational to identify the complex chemical constituents of Yinqiao Powder, which would be conducive to discover the active ingredients of Yinqiao Powder for the treatment of pneumonia and establish its quality standard.

Profiling of Phenolic Compounds of Fruit Peels of Different Ecotype Bananas Derived from Domestic and Imported Cultivars with Different Maturity

Banana is one of the most produced and consumed fruits in the world and its fruit peel accounts for about 40% of the total fresh quantity of ripe fruit, which is usually regarded as waste and poses serious environmental hazards. However, it is a promising source of natural bioactive compounds including phenolic compounds. Determination of the phenolic compounds in fruit peel from different cultivars and subgroups over a range of maturities provides convincing information for making full use of them. This study developed a sensitive and reliable analytical method—ultra-high performance liquid chromatography—coupled with electrospray ionization tandem mass spectrometry (UPLC-MS/MS) for measuring phenolic compounds in fruit peel from different ecotype cultivars and subgroups with different maturity. The results showed that quinic acid had the highest concentration ratio among the main phenolic compounds in the green/ripe peel of all banana cultivars; among all banana cultivars, the total phenolic compound contents of green banana peel were significantly higher than that of ripe banana peel; the total phenolic compound contents in the green/ripe fruit peel of non-dessert bananas were significantly higher than that of dessert bananas (green: non-dessert banana 1.48 ± 0.44 mg/g vs. dessert banana 0.97 ± 0.12 mg/g; ripe: non-dessert banana 0.26 ± 0.13 mg/g vs. dessert banana 0.19 ± 0.06 mg/g). These data provide a basis for the rational utilization of phenolic compound extractions from banana peel with huge biomass in the next step.

Comprehensive Metabolism Study of Tangeretin in Rat Plasma, Urine and Faeces Using Ultra-High Performance Liquid Chromatography-Q Exactive Hybrid Quadrupole- Orbitrap High-Resolution Accurate Mass Spectrometry

BACKGROUND

Tangeretin, present in citrus fruits, is a polymethoxy flavone with extensive pharmacological effects. It has been widely used in the clinic, but there were no detailed studies on the in vivo metabolism of tangeretin.

OBJECTIVE

This study aimed to establish a rapid and effective strategy to identify the metabolites of tangeretin and evaluate the biotransformation pathways of tangeretin in rats.

METHODS

The ultra-high performance liquid chromatography (UHPLC) equipped with a Q-Exactive Orbitrap mass spectrometer was used to identify the metabolites of tangeretin in plasma, urine and faeces of rats after intragastric administration. Based on high-resolution extracted ion chromatograms (HREICs) and parallel reaction monitoring mode (PRM), metabolites of tangeretin were identified by comparing the accurate mass, chromatographic retention times, diagnostic product ions (DPIs) and neutral loss fragments (NLFs) with those of tangeretin reference standard. Isomers were distinguished by ClogP values.

RESULTS

An efficient and integrated strategy was established for the comprehensive screening and characterizing of tangeretin metabolites through Rapid Profiling. Based on this strategy, a total of 52 metabolites were detected and identified, among which 25 metabolites were found in rat plasma, while 48 and 16 metabolites were characterized from rat urine and faeces, respectively. These metabolites were produced by demethylation, demethoxylation, hydroxylation, methoxylation, glucuronidation, glycosylation, sulfation, and their composite reactions. Interestingly, tangeretin is easy to lose methyl in vivo and becomes an intermediate product, and then other phase I and phase II reactions occur. Moreover, the characteristic fragmentation pathways of tangeretin were summarized for the subsequent metabolite identification.

CONCLUSION

The analytical method based on UHPLC-Q-Exactive mass spectrometer has the ability to quickly clarify unknown metabolism. And the the comprehensive metabolism study of tangeretin provided an overall metabolic profile, which will be of great scientific basis for further studies on tangeretin in determining its pharmacokinetics, the bioactivity of the metabolites, and clinical applications.

Quality assessment of Succus Bambusae oral liquids based on gas chromatography/mass spectrometry fingerprints and chemometrics

RATIONALE

Succus Bambusae is consumed as a kind of herbal medicine and natural beverage in China. However, the current quality standards for Succus Bambusae are low and lack safety indicators, which makes it difficult to effectively guarantee its quality. Therefore, it is of great significance to study the identification and quality control technology for the product.

METHODS

We have developed a set of qualitative and quantitative methods based on gas chromatography/mass spectrometry (GC/MS) for the analysis of volatile components in Succus Bambusae oral liquid (SBOL). Combining GC/MS fingerprint analysis and related chemometrics algorithms, with similarity evaluation, Hotelling T² and distance to Model X (DModX) as criteria, the quality consistency of different batches was evaluated, and SBOL samples from different manufacturers were differentiated.

RESULTS

Twenty-nine volatile components were preliminarily identified from 40 batches of SBOL samples from six manufacturers, and six Q-markers (Quality Markers) for the SBOLs were discussed and determined using GC/MS. The products from different manufacturers were distinguished using chemometrics.

CONCLUSIONS

The results showed that the quality of the SBOL samples from different batches and different manufacturers fluctuated greatly, which suggested that research into the raw materials and manufacturing techniques should be strengthened to improve the quality of SBOL and ensure its quality consistency.

Elucidation of glycosylation sites of kaempferol di-O-glycosides from methanolic extract of the leaves of Prunus domestica subsp. syriaca

RATIONALE

Flavonol glycosides containing the glycosylation patterns 3,4'-di-O and 4',7-di-O are rare in nature and they have not yet been studied in detail by electrospray ionization mass spectrometry (ESI-MS(+/-), in contrast to the flavonol glycosides containing the glycosylation pattern 3,7-di-O.

METHOD

The leaves from Prunus domestica L. subsp. syriaca were extracted with pure methanol or, in order to perform hydrolysis and extraction simultaneously, with a 5% methanolic solution of hydrochloric acid. The high-performance liquid chromatography (HPLC)/ESI-MS(+/-) analyses were performed using a Waters model 2690 HPLC pump and a Waters/Micromass ZQ2000 mass spectrometer.

RESULTS

Three kinds of kaempferol di-O-glycosides have been identified, namely kaempferol-3-O-hexoside-7-O-rhamnosides, kaempferol-3-O-pentoside-4'-O-rhamnosides and kaempferol 4',7-di-O-rhamnoside. The identification was performed on the basis of the abundances of the respective Y-type product ions.

CONCLUSIONS

The abundances of [Yⁿ ₀ - H]^-· , Yⁿ ₀ ^- and Yⁿ ₀ ⁺ product ions were of crucial importance for the determination of glycosylation patterns. The obtained results can be useful for HPLC/ESI-MS identification of rare flavonol-di-O-glycosides.

Detection and Identification of Catalpol Metabolites in the Rat Plasma, Urine and Faeces Using Ultra-high Performance Liquid Chromatography-Q Exactive Hybrid Quadrupole-orbitrap High-resolution Accurate Mass Spectrometry

BACKGROUND

Catalpol, an iridoid glycoside, is one of the richest bioactive components present in Rehmannia glutinosa. More and more metabolites of drugs have exhibited various pharmacological effects, thus providing guidance for clinical application. However, few researches have paid attention to the metabolism of catalpol.

OBJECTIVE

This study aimed to establish a rapid and effective method to identify catalpol metabolites and evaluate the biotransformation pathways of catalpol in rats.

METHODS

In this study, catalpol metabolites in rat urine, plasma and faeces were analyzed by UHPLC-Q-Exactive MS for the characterization of the metabolism of catalpol. Based on high-resolution extracted ion chromatograms (HREICs) and parallel reaction monitoring mode (PRM), metabolites of catalpol were identified by comparing the diagnostic product ions (DPIs), chromatographic retention times, neutral loss fragments (NLFs) and accurate mass measurement with those of catalpol reference standard.

RESULTS

A total of 29 catalpol metabolites were detected and identified in both negative and positive ion modes. Nine metabolic reactions, including deglycosylation, hydroxylation, dihydroxylation, hydrogenation, dehydrogenation, oxidation of methylene to ketone, glucuronidation, glycine conjugation and cysteine conjugation, were proposed.

CONCLUSION

A rapid and effective method based on UHPLC-Q-Exactive MS was developed to mine the metabolism information of catalpol. Results of metabolites and biotransformation pathways of catalpol suggested that when orally administrated, catalpol was firstly metabolized into catalpol aglycone, after which phase I and phase II reactions occurred. However, hydrophilic chromatography-mass spectrometry is still needed to further find the polar metabolites of catalpol.

Phytochemical profile and rosmarinic acid purification from two Peruvian Lepechinia Willd. species (Salviinae, Mentheae, Lamiaceae)

The phytochemical profile of Lepechinia meyenii (Walp.) Epling and Lepechina floribunda (Benth.) Epling obtained by liquid chromatography associated with high-resolution mass spectrometry is presented. Forty eight compounds were detected exhibiting a variety of salvianolic acids and abietane phenolic diterpenoids. A simple procedure by cold evaporative crystallization to purify rosmarinic acid from these botanical species was also shown.

Comprehensive chemical and metabolic profiling of anti-hyperglycemic active fraction from Clerodendranthi Spicati Herba

Extensive pharmacological research has demonstrated that Clerodendranthi Spicati Herba has an obvious anti-hyperglycemic effect via α-glucosidase inhibitory activity. However, the anti-hyperglycemic active fraction and its metabolic behavior in vivo have not been elaborated clearly. In this study, ultra-high-performance liquid chromatography coupled to quadrupole time of flight tandem mass spectrometry with data filtering strategy, including mass defect screening, diagnostic product ions and neutral loss identification, was established for chemical and metabolic profiling of anti-hyperglycemic active fraction from Clerodendranthi Spicati Herba. A total of 28 methoxylated flavonoids and 61 diterpenoids were rapidly identified. Four main known methoxylated flavonoids were purified and unambiguously identified by nuclear magnetic resonance analysis. Thirty-one absorbed diterpenoids, 12 absorbed methoxylated flavonoids, and 56 methoxylated flavonoids metabolites were identified in rat plasma, urine, bile, and feces after oral administration of anti-hyperglycemic active fraction. The methoxylated flavonoids were predominantly metabolized by demethylation, sulfation, and glucuronidation. Glucuronidation metabolites found in bile and urine after demethylation were dominant metabolites. Diterpenoids were absorbed into the blood mainly in the form of prototypes and excreted through bile and urine. These results indicated that methoxylated flavonoids and diterpenoids were responsible for α-glucosidase inhibitory activity, which might provide novel drug candidates for the management of diabetes mellitus.

Ultrasound-Assisted Extraction Optimization of α-Glucosidase Inhibitors from Ceratophyllum demersum L. and Identification of Phytochemical Profiling by HPLC-QTOF-MS/MS

Ceratophyllum demersum L. (CDL) is a traditional Chinese herb to treat many diseases, but research on its anti-diabetic activity is not available. In this research, the α-glucosidase inhibitory ability and phytochemical constituents of CDL extract were firstly studied. Optimal ultrasound-assisted extraction conditions for α-glucosidase inhibitors (AGIs) were optimized by single factor experiment and response surface methodology (RSM), which was confirmed as 70% methanol, liquid-to-solid ratio of 43 (mL/g), extraction time of 54 min, ultrasonic power of 350 W, and extraction temperature of 40 °C. The lowest IC₅₀ value for α-glucosidase inhibition was 0.15 mg dried material/mL (mg DM/mL), which was much lower than that of acarbose (IC₅₀ value of 0.64 mg DM/mL). In total, 80 compounds including 8 organic acids, 11 phenolic acids, 25 flavonoids, 21 fatty acids, and 15 others were identified or tentatively identified from CDL extract by HPLC-QTOF-MS/MS analysis. The results suggested that CDL could be a potential source of α-glucosidase inhibitors. It can also provide useful phytochemical information for research into other bioactivities.