Phloroglucinols with hAChE and α-glucosidase inhibitory activities from the leaves of tropic Rhodomyrtus tomentosa

Four undescribed phloroglucinol meroterpenoids, rhodotomentodiones A-D, and one undescribed phloroglucinol dimer, rhodotomentodimer A, were obtained and structurally established from tropic Rhodomyrtus tomentosa leaves. Their structures were unambiguously elucidated based on the comprehensive analyses of the NMR and MS spectroscopic data, electronic circular dichroism (ECD) calculation, and single-crystal X-ray diffraction. In particular, rhodotomentodiones A and B represent the first examples of phloroglucinol meroterpenoids featuring a unique γ-pyranoid moiety. More importantly, rhodotomentodimer A exhibited the most potential human acetylcholinesterase (hAChE) and α-glucosidase inhibitory effects with IC₅₀ values of 7.5 μM and 5.6 μM, respectively. The possible interaction sites of the above potential hAChE and α-glucosidase inhibitor were achieved by molecular docking studies. These findings greatly enrich the diversity of natural products from Myrtaceae species, and provide potential candidates for the further development of anti-Alzheimer and antidiabetic diseases.

Antifungal compounds of Chinese prickly ash against drug-resistant Candida albicans

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The antifungal activity of Chinese prickly ash leaf was comprehensively evaluated for the first time.

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Chinese prickly ash leaf extracts were characterized and 40 compounds were identified by MS/MS analysis.

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It has important for the utilization of Chinese prickly ash leaf.

The leaf of Chinese prickly ash, a unique spice having typical pungent sensation, is a popular food in Southwest China with antipruritic, insecticidal and fungicidal functions, but its bioactive constituents of fungistatic capacity remain unknown. In present investigation, twenty-nine compounds were isolated from leaf of Chinese prickly ash, and their antifungal bioactivity against drug-resistant Candida albicans were evaluated in vitro and in vivo. As a result, three compounds 3, 10, 29 showed antifungal bioactivity by damage of the fungal biofilm, and they might recover sensitive of drug resistant C. albicans to Fluconazole. Then Chinese prickly ash leaf was proved to be a functional food against fungus for the first time in experiment.

Discovery of potent immune-modulating molecule taccaoside A against cancers from structures-active relationships of natural steroidal saponins

BACKGROUND

In recent years, the T-cell therapy and immune checkpoint inhibitors toward CTLA-4 and PD-1/PD-L1 axis antibody therapy have acquired encouraging success. However, most of patients were still not benefited with lots of troubles, such as low penetration of tissues/cells, strong immunogenicity and cytokine release syndrome, and long manufacturing process and expensive costs. By contrast, the immune-modulating small molecules possessed natural advantages to overcome these obstacles and might achieve greater success.

PURPOSE

Exploring the potent immune-modulating natural small molecules and revealing what kinds of molecules or structures with the immunomodulatory activity against cancers.

METHODS

A novel non-cytotoxic T-cell immunomodulating screening model was used to identify the cytotoxic/selective/immunomodulatory bioactivity for 148 natural steroidal saponins. The structure-activity relationships (SARs) research was used to reveal the key groups for immunomodulation/cytotoxicity/selectivity. The negative selection was used to isolate and purify the T-cell. The cell viability assay was used to measure the anti-cancer effect in vitro. The ELISA assay was used to detect the cytokines for IL-1β, IL-6, TNF-α, IFN-γ, IL-12, perforin and granzyme B (GZMB). The western blotting assay was used to research the immunomodulatory mechanism. The siRNA knockdown was used to generate the IFN-γ resistant melanoma cells. The NOG immune-deficient mice were used to evaluate the anti-tumor efficacy in vivo. The peripheral blood samples from 10 cancer patients were used to detect the broad population anti-tumor efficacy.

RESULTS

It was reported that the correlation among structures and immunomodulation/ cytotoxicity/selectivity, in which opening ring-F with 26-O-glucopyranosyl, disaccharide and trisaccharide chains at C-3, steric hindrance and polarity of C-22 were key immunomodulatory groups. Moreover, taccaoside A was identified as the most potent candidate against cancer cells, including non-small cell lung cancer, triple negative breast cancer, and the IFN-γ resistant melanoma, partly through enhancing T lymphocyte mTORC1-Blimp-1 signal to secrete GZMB. Besides, 10 patients derived T-cell also would be modulated against cancer cells in vitro. Moreover, the overall survival was great extended (>140 days vs 93 days) with nearly 100% tumor burden disappearance (0 mm³vs 1006 ± 79.5 mm³) in mice.

CONCLUSION

This work demonstrated one possibility for this concerned purpose, and identified a potent immune-modulating natural molecule taccaoside A, which might contribute to cancer immunotherapy in future.

The phytochemical constituents and protective effect of Fritillaria hupehensis on acute lung injury

Acute lung injury (ALI), a severe respiratory disorder, frequently develops into acute respiratory distress syndrome (ARDS) without timely treatment and scores highly in terms of morbidity and mortality rates. Fritillaria hupehensis is a famous traditional Chinese medicine with antitussive, expectorant and anti-asthmatic effect. Here, the effects of F. hupehensis extracts on lipopolysaccharide (LPS)-induced ALI mice were evaluated for the first time. We showed ethyl acetate fraction (EAF) significantly reduced the leukocytes and neutrophils of bronchoalveolar lavage fluid (BALF) and the lung index as well as pro-inflammatory cytokines (TNF-α and IL-6) of lung homogenates but increasing the anti-inflammatory cytokines (IL-4 and IL-10). Additionally, the alleviation of EAF treatment on lung injury was verified through histopathological observations. Subsequent phytochemical investigation on bioactive fraction led to isolation of 17 compounds including two new, in which compounds 2, 5 and 6 exhibited better anti-inflammatory effect on LPS-induced 16 human airway epithelial (16HBE) cells model by inhibiting the production of CRP and PCT. Furthermore, compound 2 suppressed the LPS-induced upregulation of proteins containing p-p65, COX-2, Caspase-1 and IL-18. In summary, F. hupehensis alleviating LPS-induced ALI in mice may be associated with the anti-inflammatory activity of steroidal alkaloids by suppressing the NF-κB-regulated pro-inflammatory proteins.

New steroidal alkaloids with anti-inflammatory and analgesic effects from Veratrum grandiflorum

ETHNOPHARMACOLOGICAL RELEVANCE

"Li-Lu", the roots and rhizomes of Veratrum grandiflorum (Melianthiaceae), has been historically used as a traditional folk medicine for the treatment of wrist pain, fractures, sores, and inflammation in Yunnan Province, China. However, the anti-inflammatory and analgesic studies of this plant have seldom reported.

AIM OF THE STUDY

To evaluate the anti-inflammatory and analgesic properties related to the traditional usage of V. grandiflorum both in vitro and in vivo, and further explore the accurate bioactive compounds from the medicinal plant.

MATERIALS AND METHODS

Phytochemical investigation was carried out by chromatographic methods and their structures were established based on extensive spectra and comparison with corresponding data in the reported literatures. Anti-inflammatory activities were assessed by the suppression of lipopolysaccharide-activated inflammatory mediators in RAW 264.7 macrophage cells in vitro. Furthermore, anti-inflammatory and analgesic effects were evaluated based on carrageenan-induced paw edema and acetic acid-stimulated writhing in mice.

RESULTS

The methanol extract (ME) of V. grandiflorum significantly alleviated the paw edema caused by carrageenan and the writhing numbers induced by acetic acid. Subsequent phytochemical investigation led to isolated of 21 steroidal alkaloids, including seven new compounds, veragranines C-I (1-7). Anti-inflammatory test indicated that steroidal alkaloids could decrease the expression of cyclooxygenase-2 (COX-2), interleukin-1β (IL-1β), and tumor necrosis factor α (TNF-α) in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells at a concentration of 5.0 μg/ml in vitro, comparable to DXM. Moreover, five new steroidal alkaloids (2, 4, 5, 6, and 7) and two major steroidal alkaloids (9 and 13) significantly decreased the numbers of writhing in mice at the doses of 0.5 and/or 1.0 mg/kg (p < 0.01/0.05), roughly comparable to Dolantin™ at 10.0 mg/kg.

CONCLUSIONS

The investigation supported the traditional use of V. grandiflorum and provided new steroidal alkaloids as potent analgesic agents.

Effect of hydrophile-lipophile balance of the linker in Gal/GalNAc ligands on high-affinity binding of galactosylated liposomes by the asialoglycoprotein receptor

In this study, we explored the effect of the hydrophile-lipophile balance (HLB) in the linker unit of Galactose (Gal)/N-acetylgalactosamine (GalNAc) ligands on their affinity toward asialoglycoprotein receptors (ASGPRs). Two Gal/GalNAc ligands with lipophilic linkers-{(5-cholesten-3b-ol)[(2-acetamido-2-deoxy-d-galactopyranose-6-o)sebacate]} (CHS-6-GalNAc) and {(5-cholesten-3b-ol)[(d-galactopyranose-6-o)sebacate]} (CHS-6-Gal)-and two with hydrophilic linkers-{(5-cholesten-yl)[(4-O-b-D-galactopyranosyl)-D-glucitol-6-yl]sebacate} (CHS-1-Gal) and {(5-cholesten-3a-ol)[(2-acetamido-2-deoxy-d-galactopyranose-6-o)3,6-dioxa-octanedioate]} (CHS-PEG₂-6-GalNAc)-were synthesized by enzymatic catalysis. Compared with unmodified liposomes, all Gal/GalNAc ligand-modified liposomes showed higher efficiency toward the hepatocyte target as evaluated by weighted-average overall drug-targeting efficiency (Te*) in vivo and HepG2 cell uptake efficiency in vitro. The ligands containing linkers with high HLB values (i.e., CHS-PEG₂-6-GalNAc and CHS-1-Gal) exhibited higher ASGPR affinity than those containing linkers with low HLB values (i.e., CHS-6-GalNAc and CHS-6-Gal). We used molecular-dynamics (MD) simulations to investigate the structure-activity relationship between the HLB value of the linker in a ligand and ASGPR affinity. MD simulation results indicated that a Gal/GalNAc ligand with a more hydrophilic linker (i.e., higher HLB value) unit tended to have a higher solvent-accessible surface area (SASA), leading to lower steric hindrance for effective ASGPR recognition. The results of this study will provide an improved design for Gal/GalNAc ligand-based surface-modified liposomes with high ASGPR affinity.

Tuberindine A, a Truffle Alkaloid with an Unprecedented Skeleton Exhibiting Anti-hyperuricemic Bioactivity

Tuberindines A and B (1 and 2), truffle alkaloids with intriguing structures, were isolated from Tuber indicum and detected in other truffle species. They appear to arise biosynthetically from amino acid and isosaccharinic units. Compound 1 upregulated the expression of organic anion transporters OAT1 and ABCG2 and significantly exhibited antihyperuricemic bioactivity in vitro and in vivo, which might support the value of truffles as a dietary supplement.

The Protective Effect of Sweet Potato Root Tuber on Chemotherapy-Induced Thrombocytopenia

SCOPE

Sweet potato (Ipomoea batatas L.) is one of the leading crops worldwide, containing high nutritional components such as fiber and polyphenols. Root tuber of Simon 1 (SIMON), a cultivar of sweet potato, is a folk food in China with a hemostasis function but lacking experimental data support.

METHODS AND RESULTS

Now the protective effect of SIMON on chemotherapy-induced thrombocytopenia (CIT), a serious complication of cancer treatment, is investigated for the first time by a CIT mouse model induced by intraperitoneal injection of carboplatin. As a result, SIMON raises the number of peripheral platelets, white blood cells, and bone marrow nucleated cells in CIT mice significantly. Besides, carboplatin-induced atrophy of the thymus, spleen, and disordered metabolism of the inflammatory immune system and glycerophospholipids are also reversed by SIMON. Phytochemical analysis of SIMON indicates 16 compounds including eight phenolic derivatives, which might be associated with its anti-CIT bioactivity.

CONCLUSION

Sweet potato (SIMON) may be an efficient function food in the prevention of bleeding disorders.

Chemistry and bioactivities of natural steroidal alkaloids

Steroidal alkaloids possess the basic steroidal skeleton with a nitrogen atom in rings or side chains incorporated as an integral part of the molecule. They have demonstrated a wide range of biological activities, and some of them have even been developed as therapeutic drugs, such as abiraterone acetate (Zytiga^®), a blockbuster drug, which has been used for the treatment of prostate cancer. Structurally diverse natural steroidal alkaloids present a wide spectrum of biological activities, which are attractive for natural product chemistry and medicinal chemistry communities. This review comprehensively covers the structural classification, isolation and various biological activities of 697 natural steroidal alkaloids discovered from 1926 to October 2021, with 363 references being cited.

Anti-hyperuricemic bioactivity of Alstonia scholaris and its bioactive triterpenoids in vivo and in vitro

ETHNOPHARMACOLOGY RELEVANCE

One folk use of Alstonia scholaris (L.) R. Br. in "Dai" ethno-medicine system is to treat gouty arthritis, which might be caused by hyperuricemia, but anti-hyperuricemic investigation of A. scholaris were rarely reported.

AIM OF THE STUDY

To verify anti-hyperuricemic property of A. scholaris, and explore its bioactive compounds in vivo and in vitro.

MATERIALS AND METHODS

The anti-hyperuricemic bioactivity of the non-alkaloids fraction and compounds were evaluated with potassium oxonate (PO) induced hyperuricemia mice model in vivo, and monosodium urate (MSU) induced human renal tubular epithelial cells (HK-2) was selected to test in vitro, respectively, with benzobromarone as the positive control. 11 triterpenoids were isolated by phytochemical methods and their structures were elucidated by spectroscopic analysis and ECD calculation.

RESULTS

The non-alkaloids fraction of A. scholaris decreased the serum uric acid (UA) level in mice model significantly at the doses of 100 mg/kg and 200 mg/kg, and then nine ursane- and two oleanane-triterpenoids including four new compounds (1-3 and 10) were isolated from the bioactive fraction, in which compounds 1, 4, 5, 6 and 10 exhibited better anti-hyperuricemic tendency in vitro by promoting the excretion of UA in MSU-induced HK-2 cell model at a concentration of 5 μM. Furthermore, compounds 1 and 4 were proved to reduce the serum UA level in mice significantly at 5 mg/kg in vivo.

CONCLUSIONS

The results supported the traditional use of A. scholaris in treating gouty arthritis, and also provided new bioactive triterpenoids for further chemical and pharmacological investigation.

Baoshanmycin and a New Furanone Derivative from a Soil-Derived Actinomycete, Amycolatopsis sp. YNNP 00208

Actinomycetes have being regarded as a treasure reservoir of various bioactive secondary metabolites and devoted many antibiotics in clinicals. Amycolatopsis sp. YNNP 00208 was isolated from a soil sample collected in Gaoligong Mountain area, Yunnan Province, China. Chemical investigation of its fermentation broth led to a new amide, baoshanmycin (1), and a new furanone derivative, 3-(1,3-dihydroxybutyl)-4-methylfuran-2(H)-one (2), together with eight known compounds, including two amides (3-4), four cyclic dipeptides (5-8), and two deoxyribonucleosides (9-10). Their structures were established on basis of the 1D- and 2D-NMR spectroscopic data, along with the HR-ESI-MS experiments. Baoshanmycin (1) showed moderate antimicrobial activities against Candida albicans, and weak activities against Staphylococcus aureus, multi-drug resistant Staphylococcus aureus, Bacillus subtilis, Listeria monocytogenes, fluconazole-resistant Candida albicans. Baoshanmycin (1) presented strong antioxidant activity and moderate anti-acetylcholinesterase activity. The other compound 3-(1,3-dihydroxybutyl)-4-methylfuran-2(H)-one (2) and the known compounds (3-10) showed moderate antioxidant activity.

Phytochemical and Antibacterial Constituents of Edible Globe Amaranth Flower against Pseudomonas aeruginosa

Globe amaranth flower, the edible inflorescence of Gomphrena globose L., was used to treat dysentery and ulcer as well as other infectious diseases caused by microbes in Southwest China, but its function and bioactive components need experimental support. In this study, phytochemical constituents and antibacterial bioactivity of globe amaranth flower against P. aeruginosa were carried out. As a result, two new (1 and 2) and eleven known (3-11) compounds were isolated, in which compounds 4-7 displayed anti P. aeruginosa bioactivity with the minimum inhibitory concentration (MIC) from 0.008 to 0.256 mg/mL. Furthermore, with aid of the scanning electron microscope (SEM) and a superficial skin infection model in mice, the most potent compound 4 can significantly destroy the structure of bacteria in vitro and restore bacterial infection damage in vivo.

Indole alkaloids of Alstonia scholaris (L.) R. Br. alleviated nonalcoholic fatty liver disease in mice fed with high-fat diet

Alstonia scholaris (L.) R. Br (Apocynaceae) is a well-documented medicinal plant for treating respiratory diseases, liver diseases and diabetes traditionally. The current study aimed to investigate the effects of TA on non-alcoholic fatty liver disease (NAFLD). A NAFLD model was established using mice fed a high-fat diet (HFD) and administered with TA (7.5, 15 and 30 mg/kg) orally for 6 weeks. The biochemical parameters, expressions of lipid metabolism-related genes or proteins were analyzed. Furthermore, histopathological examinations were evaluated with Hematoxylin-Eosin and MASSON staining. TA treatment significantly decreased the bodyweight of HFD mice. The concentrations of low-density lipoprotein (LDL), triglyceride (TG), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were also decreased significantly in TA-treated mice group, accompanied by an increase in high-density lipoprotein (HDL). Furthermore, TA alleviated hepatic steatosis injury and lipid droplet accumulation of liver tissues. The liver mRNA levels involved in hepatic lipid synthesis such as sterol regulatory element-binding protein 1C (SREBP-1C), regulators of liver X receptor α (LXRα), peroxisome proliferator activated receptor (PPAR)γ, acetyl-CoA carboxylase (ACC1) and stearyl coenzyme A dehydrogenase-1 (SCD1), were markedly decreased, while the expressions involved in the regulation of fatty acid oxidation, PPARα, carnitine palmitoyl transterase 1 (CPT1A), and acyl coenzyme A oxidase 1 (ACOX1) were increased in TA-treated mice. TA might attenuate NAFLD by regulating hepatic lipogenesis and fatty acid oxidation.

Phytochemical and anti-MRSA constituents of Zanthoxylum nitidum

Infectious diseases caused by multidrug-resistant bacteria such as methicillin-resistant Staphylococcus aureus, pose a significant threat to humanity. Persistent and repeated invasive infection with MRSA led to higher morbidity and mortality, and required comprehensive measures in treatment and prevention. Zanthoxylum nitidum (Roxb.) DC. is used as detoxifying, analgesic, and hemostatic herbal medicine for thousands of years. Previously pharmacological studies showed that Z. nitidum had antibacterial bioactivity, but only the MIC of a few compounds, crude extracts, and fractions were reported. In our ongoing endeavor to explore bioactive compounds, two new coumarins, 6-(3-oxo-butyl)-limettin (1) and toddalin I (2), and 24 known compounds were isolated from the roots of Z. nitidum, in which two isoquinoline alkaloids, 6-acetonyl-dihydrofagaridine (16) and 6-acetonyl-dihydrochelerythrine (17) showed anti-MRSA bioactivity in vitro and in vivo. Both 16 and 17 showed synergistic action with ampicillin, which decreased the MIC significantly, and both compounds had a significant ability to destroy bacterial biofilm combined with ampicillin. The combined administration showed a strong scavenging effect on the planktonic bacteria in vitro and cleared skin infection effectively in the model of wound infection in vivo. Furthermore, compound 16 inhibited the efflux of the drug by combining with ampicillin or EtBr, resulting in the MIC decreased obviously. Our investigation supported the traditional use of Z. nitidum in treating infections caused by bacteria, and might provide new natural products to reduce the use of antibiotics and the treatment of drug-resistance bacteria.

The clinical population pharmacokinetics, metabolomics and therapeutic analysis of alkaloids from Alstonia scholaris leaves in acute bronchitis patients

BACKGROUND

Capsule of alkaloids from leaf of Alstonia scholaris (CALAS) is a new investigational botanical drug (No. 2011L01436) for respiratory disease. Clinical population pharmacokinetics (PK), metabolomics and therapeutic data are essential to guide dosing in patients. Previous research has demonstrated the potential therapeutic effect of CALAS on acute bronchitis. Further clinical trial data are needed to verify its clinical efficacy, pharmacokinetics behavior, and influence of dosage and other factors.

PURPOSE

To verify the clinical efficacy and explore the potential biomarkers related to CALAS treatment for acute bronchitis.

MATERIALS AND METHODS

Oral CALAS was assessed in a randomized, double-blind, placebo-controlled trial. Fifty-five eligible patients were randomly assigned to four cohorts to receive 20, 40 or 80 mg, of CALAS three times daily for seven days, or placebo. Each CALAS cohort included 15 subjects, and the placebo group included 10 subjects. A population PK model of CALAS was developed using plasma with four major alkaloid components. Metabolomics analysis was performed to identify biomarkers correlated with the therapeutic effect of CALAS, and efficacy and safety were assessed based on clinical symptoms and adverse events.

RESULTS

The symptoms of acute bronchitis were alleviated by CALAS treatment without serious adverse events or clinically significant changes in vital signs, electrocardiography or upper abdominal Doppler ultrasonography. Moreover, one compartment model with first-order absorption showed that an increase in aspartate transaminase will reduce the clearance (CL) of scholaricine, and picrinine CL was inversely proportional to body mass index, while 19-epischolaricine and vallesamine CL increased with aging. The serum samples from acute bronchitis patients at different time points were analyzed using UPLC-QTOF in combination with the orthogonal projection to latent structures-discriminant analysis, which indicated higher levels of lysophosphatidylcholines, lysophosphatidylethanolamines and amino acids with CALAS treatment than with placebo.

CONCLUSION

This is the first study to evaluate the clinical efficacy and explored the potential biomarkers related to CALAS therapeutic mechanism of acute bronchitis by means of clinical trial combined the metabolomics study. This exploratory study provides a basis for further research on clinical efficacy and optimal dosing regimens based on pharmacokinetics behavior. Additional acute bronchitis patients and CALAS PK samples collected in future studies may be used to improve model performance and maximize its clinical value.

Anti-inflammatory and analgesic monoterpenoid indole alkaloids of Kopsia officinalis

ETHNOPHARMACOLOGICAL RELEVANCE

"Ya gai", an important part of Dai medical theory, is traditionally recognized as an antidote. Kopsia officinalis Tsiang et P. T. Li is a "Ya gai" related medicine and has been widely used by Dai people for the treatment of pain and inflammation. Previous literature on title species suggested that monoterpenoid indole alkaloids (MIAs) could be its main bioactive components. However, the specific bioactive ingredients for inflammation-related treatment are still unrevealed, which inspired us to conduct a phytochemical and pharmacological investigation related to its traditional use.

AIM OF THE STUDY

To support the traditional use of K. officinalis by assessing the anti-inflammatory and analgesic effects of its purified MIAs.

MATERIAL AND METHODS

Compounds were isolated and purified from the barks and leaves of K. officinalis using diverse chromatographic methods. The structures were established by means of extensive spectroscopic analyses and quantum computational technique. The anti-inflammatory activities of the purified MIAs were evaluated in vitro based on the suppression of lipopolysaccharide-activated inflammatory mediators (COX-2, IL-1β, and TNF-α) in RAW 264.7 macrophage cells. Anti-inflammatory and analgesic activities in vivo were assessed with carrageenan-induced paw edema and acetic acid-stimulated writhing in mice models.

RESULTS

23 MIAs including four new compounds were obtained and structurally established. Most of isolates showed significant anti-inflammatory effects in vitro by inhibiting inflammatory mediators (COX-2, IL-1β, and TNF-α). Further pharmacological evaluation in vivo revealed that 12-hydroxy-19(R)-hydroxy-ibophyllidine (1) and 11,12-methylenedioxykopsinaline N⁴-oxide (5) remarkably decreased the number of writhing, while kopsinic acid (8), (-)-kopsinilam (12), and normavacurine-21-one (20) significantly relieved paw edema, respectively, even better than the positive control aspirin.

CONCLUSIONS

The in vitro and in vivo findings supported the traditional use of K. officinalis with respect to its anti-inflammatory and analgesic effect, as well as provided potent bioactive MIAs for further chemical modification and pharmacological investigation.

Bioguided isolation, identification and bioactivity evaluation of anti-MRSA constituents from Morus alba Linn

ETHNOPHARMACOLOGY RELEVANCE

The root bark of Morus alba Linn. (M. alba), a traditional folk medicine, has been documented in the Chinese Pharmacopoeia, which has been widely used for asthma, fever, pneumonia, edema, vomit, colitis, bronchitis and keratitis diseases. Some of the diseases may be related to respiratory, digestive, urinary tract infections. Although Diels-Alder adducts (DAAs), flavonoids, 2-arylbenzofurans and stilbene compounds have been isolated from the root bark of M. alba, few compounds are reported for their antimicrobial efficacy in vivo and the mechanism.

AIM OF THE STUDY

The aim of the study was to isolate and identify compounds of the root bark of M. alba in view of their anti-MRSA bioactivity, evaluate the anti-MRSA bioactivity of compounds and 60% ethanol elution (MA-6) in vitro and in vivo, and explore preliminary antibacterial mechanism in order to provide natural resources against MRSA infection.

MATERIALS AND METHODS

Systematic phytochemical investigations were carried out according to the thin layer chromatography (TLC) of the active fraction MA-6 to find more anti-MRSA ingredients. The compounds of the root bark of M. alba were separated by column chromatography and identified by LC-MS/MS and NMR spectroscopy. The anti-MRSA efficacy of the active ingredients were evaluated by broth microdilution method and a murine infection model. The mode of action of compounds was explored by time-kill curve and post-contact effect. The preliminary mechanism of compounds against MRSA was explored by drug efflux pumps and bacterial biofilms.

RESULTS

Chemical isolation resulted in twenty-nine known compounds, most with one or more geranyl and prenyl units exhibited superior anti-MRSA bioactivity, with MIC values of 2-16 μg/mL. In addition, the mode of action indicated that compounds presented persistent antimicrobial effect, which also produced concentration-dependent and time-dependent killing activity or property. Preliminary mechanism showed that the compound kuwanon O (29) damaged the bacterial cell membranes, leading to the accumulation of antibiotics inside bacterial cells, moreover, MA-6 and kuwanon O (29) inhibited the efflux of drugs by combining with methicillin or ethidium bromide (EtBr), resulting in the MICs of EtBr and methicillin were obviously decreased three-fold. The anti-MRSA efficacy in vivo indicated that the active fraction MA-6 could reduce bacteria in spleen, liver, kidney and mortality of acutely infectious mice, which was better than the positive drug berberine chloride.

CONCLUSION

Experimental investigation showed that the MA-6 and compound 29 have promising bioactivity against MRSA in vitro and in vivo, which might be used as a potential source of new antibacterial medicine or a potential efflux pump inhibitor against MRSA infection.

Furostanol Saponins from Asparagus cochinchinensis and Their Cytotoxicity

Phytochemical investigation on the roots of Asparagus cochinchinensis led to the isolation of one new furostanol saponin, named 26-O-β-D-glucopyranosyl-22α-hydroxyl-(25R)-Δ5(6)-furost-3β,26-diol-3-O-α-L-rhamnopyranosyl-(1 → 2)-[β-D-glucopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 4)]-β-D-glucopyranoside (1), along with three known congeners (2‒4). The structure of new saponin was elucidated via comprehensive inspection of its HRMS and NMR spectral data as well as chemical technology, whereas those of known ones were identified by comparison of their NMR and MS spectral data with those reported in literatures. All isolated saponins were evaluated for their cytotoxic effects on two human liver (MHCC97H) and lung adenocarcinoma (H1299) cancer cells in vitro. Among them, both 1 and 2 showed significant cytotoxicity against above mentioned cell lines. Further studies revealed that these two saponins could significantly inhibit their proliferation of MHCC97H and H1299 cells.

The safety and tolerability of alkaloids from Alstonia scholaris leaves in healthy Chinese volunteers: a single-centre, randomized, double-blind, placebo-controlled phase I clinical trial

CONTEXT

Capsule of alkaloids from the leaf of Alstonia scholaris (L.) R.Br. (Apocynaceae) (CALAS) is a new investigational botanical drug (No. 2011L01436) for bronchitis, post-infectious cough and asthma.

OBJECTIVE

To observe the clinical safety and tolerability of CALAS.

MATERIALS AND METHODS

Subjects were assigned to eight cohorts, and each received randomly CALAS or placebo in one of single ascending dose (SAD) of 8, 40, 120, 240, 360, 480, or in one of multiple ascending dose (MAD) of 40 or 120 mg, three times daily for 7 days. Each cohort contained two placebo subjects.

RESULTS

Sixty-two enrolled volunteers completed the study and no serious adverse events and clinically significant changes in vital signs, electrocardiography, and upper abdominal Doppler ultrasonography were observed. The ratios of treatment-emergent adverse events (TEAEs) were reported in 11/46 (23.91%) of CALAS groups and 3/16 (18.75%) of the placebo group (p > 0.05), respectively, based on the results of SAD and MAD. All TEAEs were mild, transient, and disappeared without any intervention. The TEAEs possibly related to CALAS treatment were as followings: hiccups (4/46: 8%), dry mouth and nausea (3/46: 6%), increased sleep (2/46: 4%), abdominal distension (1/46: 2%), bilirubin elevated (1/46: 2%).

DISCUSSION AND CONCLUSIONS

CALAS is safe and well-tolerated with no unexpected or clinically relevant safety concerns up to a single dose of 360 mg and three times daily for 7 days up to 120 mg in healthy Chinese volunteers, supporting further Phase II studies.

C19 Benzylisoquinoline Alkaloid with Unprecedented Architecture from Hypecoum erectum

Hyperectumine (1), the first C₁₉ benzylisoquinoline alkaloid with a complicated ring system, was isolated from Hypecoum erectum and structurally characterized. Its biosynthetic origin should involve a hybrid pattern of C₈ + C₈ + C₁ + C₂, from which a C₁₇ benzylisoquinoline alkaloid might be further attacked by a malonamic acid and undergo decarboxylation and cyclization to produce 1. Compound (-)-1 exhibited moderate anti-inflammatory activity via suppression of LPS-activated inflammatory mediators in RAW 264.7 macrophage cells.

Migration of (non-) intentionally added substances and microplastics from microwavable plastic food containers

Microwavable plastic food containers (MPFCs) are extensively used for food storage, cooking, rapid heating and as take-out containers. There is an urgent need to investigate whether MPFCs pose potential health risks, as a result of the migration of chemicals into foods. Herein, 42 intentionally added substances (IAS) and > 100 non-IAS (NIAS) migrating from MPFCs were identified in food simulants according to Regulation (EU). The migration of major IAS and NIAS was higher in 95% ethanol compared to other simulants, and gradually decreased following repeated use. NIAS, including Cramer class III toxic compounds, such as PEG oligomers of N,N-bis(2-hydroxyethyl) alkyl(C8-C18)amines, isomers of hexadecanamide and oleamide, and Irgafos 168 OXO were detected and exceeded the recommended limits in some MPFCs. Furthermore, microplastics (MPs) were detected with high values of over one million particles/L in some MPFCs in a single test, and migration behaviors of MPs in different MPFCs were diverse. Surprisingly, this rigorous migration might result in an annual intake of IAS/NIAS up to 55.15 mg and 150 million MPs particles if take-out food was consumed once a day. Multi-safety evaluation studies on the migration of various chemicals from MPFCs to foodstuffs during food preparation should be assessed.

Steroidal Alkaloids with a Potent Analgesic Effect Based on N-type Calcium Channel Inhibition

Two distinctive alkaloids with 6/6/6/5/6/6 fused rings, in which a previously unidentified linkage of C-12/23 generates a rigid skeleton, resulting in a new subtype of steroidal alkaloid, were isolated from Veratrum grandiflorum. Compounds 1 and 2 showed potent analgesic effects in vivo, superior to the well-known analgesic, pethidine (Dolantin), likely by inhibiting Ca_V2.2 voltage-gated calcium channels.

Development of a LC-HRMS based approach to boost structural annotation of isomeric citrus flavanones

INTRODUCTION

The structural annotation of target relies on high-resolution mass spectrometry (HRMS) information resulting in dubious identities in most cases. The accurate annotation of isomeric structures is still challenging to be confirmed with significant bottleneck.

OBJECTIVE

This study focused on the improvement of structural annotation of candidate structures via four pairs of isomeric flavanone-7-O-diglucosides and their basic flavanone aglycones commonly detected in citrus products.

METHOD

An integrated liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS) approach merging retention time, accurate mass, tandem mass spectrometry (MS/MS) information (diagnostic ions), ion ratio at selected collision energy was established successfully.

RESULTS

Feasibility of this approach was validated confidently in biological samples with relative standard deviation (RSD) of ion ratio range from 3.91 to 12.28%. Differences of fragmentation patterns of citrus flavanones were illustrated reasonably. MS/MS fragments of (S)-hesperetin and (S)-isosakuranetin were complicated and showed typical radical ion [^1,2 A - H]^•- (m/z 164) in negative ESI mode due to the methoxyl group on B-ring, which showed huge difference with (R)-hesperetin and (R)-isosakuranetin.

CONCLUSION

This study integrated multiple levels to boost the confidence of structural annotation relied on LC-HRMS, and provided important values in practice for precise identification of citrus flavanones in biological matrices.

Koninginin W, a New Polyketide from the Endophytic Fungus Trichoderma koningiopsis YIM PH30002

A new compound named koninginin W (1) and four known polyketides (2-5) were isolated from endophytic fungus Trichoderma koningiopsis YIM PH30002 of Panax notoginseng. The structures of 1 - 5, including absolute configuration of 1, were elucidated on the detailed analysis of the HR-ESI-MS, 1D and 2D NMR, and X-ray crystallographic data. Koninginin W (1) presented weak antibacterial activity against Escherichia coli, Bacillus subtilis and Salmonella typhimurium.