A genomic compendium of cultivated human gut fungi characterizes the gut mycobiome and its relevance to common diseases.

The gut fungal community represents an essential element of human health, yet its functional and metabolic potential remains insufficiently elucidated, largely due to the limited availability of reference genomes. To address this gap, we presented the cultivated gut fungi (CGF) catalog, encompassing 760 fungal genomes derived from the feces of healthy individuals. This catalog comprises 206 species spanning 48 families, including 69 species previously unidentified. We explored the functional and metabolic attributes of the CGF species and utilized this catalog to construct a phylogenetic representation of the gut mycobiome by analyzing over 11,000 fecal metagenomes from Chinese and non-Chinese populations. Moreover, we identified significant common disease-related variations in gut mycobiome composition and corroborated the associations between fungal signatures and inflammatory bowel disease (IBD) through animal experimentation. These resources and findings substantially enrich our understanding of the biological diversity and disease relevance of the human gut mycobiome.

Kurarinone alleviated Parkinson's disease via stabilization of epoxyeicosatrienoic acids in animal model.

Parkinson's disease (PD) is one of the most common neurodegenerative disorders and is characterized by loss of dopaminergic neurons in the substantia nigra (SN), causing bradykinesia and rest tremors. Although the molecular mechanism of PD is still not fully understood, neuroinflammation has a key role in the damage of dopaminergic neurons. Herein, we found that kurarinone, a unique natural product from Sophora flavescens, alleviated the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced behavioral deficits and dopaminergic neurotoxicity, including the losses of neurotransmitters and tyrosine hydroxylase (TH)-positive cells (SN and striatum [STR]). Furthermore, kurarinone attenuated the MPTP-mediated neuroinflammation via suppressing the activation of microglia involved in the nuclear factor kappa B signaling pathway. The proteomics result of the solvent-induced protein precipitation and thermal proteome profiling suggest that the soluble epoxide hydrolase (sEH) enzyme, which is associated with the neuroinflammation of PD, is a promising target of kurarinone. This is supported by the increase of plasma epoxyeicosatrienoic acids (sEH substrates) and the decrease of dihydroxyeicosatrienoic acids (sEH products), and the results of in vitro inhibition kinetics, surface plasmon resonance, and cocrystallization of kurarinone with sEH revealed that this natural compound is an uncompetitive inhibitor. In addition, sEH knockout (KO) attenuated the progression of PD, and sEH KO plus kurarinone did not further reduce the protection of PD in MPTP-induced PD mice. These findings suggest that kurarinone could be a potential natural candidate for the treatment of PD, possibly through sEH inhibition.

Discovery of Potential Antituberculosis Agents Targeted Methionine Aminopeptidase 1 of Mycobacterium tuberculosis by the Developed Fluorescent Probe.

Tuberculosis (TB) is a chronic systemic infectious disease caused by Mycobacterium tuberculosis (M. tuberculosis). Methionine aminopeptidase 1 (MtMET-AP1) is a hydrolase that mediates the necessary post-translational N-terminal methionine excision (NME) of peptides during protein synthesis, which is necessary for bacterial proliferation and is a potential target for the treatment of tuberculosis. Based on the functional characteristics of MtMET-AP1, we developed an enzymatic activated near-infrared fluorescent probe DDAN-MT for rapid, highly selective, and real-time monitoring of endogenous MtMET-AP1 activity in M. tuberculosis. Using the probe DDAN-MT, a visually high-throughput screening technique was established, which obtained three potential inhibitors (GSK-J4 hydrochchloride, JX06, and lavendustin C) against MtMET-AP1 from a 2560 compounds library. More importantly, these inhibitors could inhibit the growth of M. tuberculosis H37Ra especially (MICs < 5 µM), with low toxicities on intestinal bacteria strains and human cells. Therefore, the visual sensing of MtMET-AP1 was successfully performed by DDAN-MT, and MtMET-AP1 inhibitors were discovered as potential antituberculosis agents.

OAT3 Participates in Drug-Drug Interaction between Bentysrepinine and Entecavir through Interactions with M8-A Metabolite of Bentysrepinine-In Rats and Humans In Vitro.

Bentysrepinine (Y101) is a novel phenylalanine dipeptide for the treatment of hepatitis B virus. Renal excretion played an important role in the elimination of Y101 and its metabolites, M8 and M9, in healthy Chinese subjects, although the molecular mechanisms of renal excretion and potential drug-drug interactions (DDIs) remain unclear. The present study aimed to determine the organic anion transporters (OATs) involved in the renal disposition of Y101 and to predict the potential DDI between Y101 and entecavir, the first-line agent against HBV and a substrate of OAT1/3. Pharmacokinetic studies and uptake assays using rat kidney slices, as well as hOAT1/3-HEK293 cells, were performed to evaluate potential DDI. The co-administration of probenecid (an inhibitor of OATs) significantly increased the plasma concentrations and area under the plasma concentration-time curves of M8 and M9 but not Y101, while reduced renal clearance and the cumulative urinary excretion of M8 were observed in rats. The time course of Y101 and M8 uptake via rat kidney slices was temperature-dependent. Moreover, the uptake of M8 was inhibited significantly by probenecid and benzylpenicillin, but not by p-aminohippurate or tetraethyl ammonium. M8 was found to be a substrate of hOAT3, but Y101 is not a substrate of either hOAT1 or hOAT3. Additionally, the entecavir inhibited the uptake of M8 in the hOAT3-transfected cells and rat kidney slices in vitro. Interestingly, no significant changes were observed in the pharmacokinetic parameters of Y101, M8 or entecavir, regardless of intravenous or oral co-administration of Y101 and entecavir in rats. In conclusion, M8 is a substrate of OAT3 in rats and humans. Furthermore, M8 also mediates the DDI between Y101 and entecavir in vitro, mediated by OAT3. We speculate that it would be safe to use Y101 with entecavir in clinical practice. Our results provide useful information with which to predict the DDIs between Y101 and other drugs that act as substrates of OAT3.

Cultivated human intestinal fungus Candida metapsilosis M2006B attenuates colitis by secreting acyclic sesquiterpenoids as FXR agonists.

OBJECTIVE: Dysbiosis of the intestinal fungal community has been observed in inflammatory bowel disease (IBD); however, its potential role in IBD development and prevention remains unclear. Here, we explored the biological effects and molecular mechanisms of intestinal fungi isolated from human faeces on colitis in mice. DESIGN: Intestinal fungal strains with differential abundance in IBD were cultivated in human faeces and their effects on various mouse models of experimental colitis were evaluated. In addition, the bioactive metabolites secreted by the target fungus were accurately identified and their pharmacological effects and potential molecular targets were investigated in vitro and in vivo. RESULTS: The abundance of Candida spp was significantly higher in patients with IBD. After large-scale human intestinal fungal cultivation and functional analysis, Candida metapsilosis M2006B significantly attenuated various models of experimental colitis in wild-type, antibiotic-treated, germ-free, and IL10-/- mice by activating farnesoid X receptor (FXR). Among the seven acyclic sesquiterpenoids (F1-F7) identified as major secondary metabolites of M2006B, F4 and F5 attenuated colitis in mice by acting as novel FXR agonists. The therapeutic effects of M2006B and its metabolites on colitis via specific FXR activation were confirmed in Fxr -/- mice. CONCLUSION: This study revealed that C. metapsilosis M2006B significantly attenuated colitis in mice and identified two acyclic sesquiterpenoids (F4 and F5) as major active metabolites of M2006B. Notably, these metabolites were able to effectively treat experimental colitis by selectively activating FXR. Together, this study demonstrates that M2006B could be a beneficial intestinal fungus for treating and preventing IBD.

Biogenetic and biomimetic synthesis of natural bisditerpenoids: hypothesis and practices.

Covering: up to March 2022Bisditerpenoids, or diterpenoid dimers, are a group of natural products with high structural variance, deriving from homo- or hetero-dimeric coupling of two diterpenoid units. They usually possess complex architectures resulting from the diversity of monomeric diterpenoids as building blocks and the dimerization processes. These compounds have attracted the attention of synthetic and biological scientists owing to the rarity of their natural origin and their significant biological activities. Herein, we provide a review highlighting some of the interesting bisditerpenoids reported since 1961 and showcase the chemical diversity in both their structures and biosynthesis, as well as their biological functions. This review focuses on the biosynthetic dimerization pathways of interesting molecules and their biomimetic synthesis, which may act as useful inspiration for the discovery and synthesis of more bisditerpenoids and further pharmacological investigations.

Endoplasmic Reticulum-Targeting Near-Infrared Fluorescent Probe for CYP2J2 Activity and Its Imaging Application in Endoplasmic Reticulum Stress and Tumor.

CYP2J2 as an endoplasmic reticulum (ER)-expressed vital cytochrome P450 isoform participates in the metabolism of endogenous polyunsaturated fatty acids. Its abnormal expression and function are closely related to the progress of cancer and cardiovascular diseases. Herein, an ER-targeting near-infrared (NIR) fluorescent probe ER-BnXPI was developed for monitoring CYP2J2 activity, which possessed a high selectivity and sensitivity toward CYP2J2 among various CYP450 isoforms and exhibited excellent subcellular localization for ER. Then, the CYP2J2 variation behavior under the ER stress model was imaged by ER-BnXPI in living cells and successfully used for the in vivo imaging in different tumors that well distinguished tumor tissues from para-cancerous tissues. All these findings fully demonstrated that ER-BnXPI could be used as a promising tool for exploring the physiological function of CYP2J2 and provided some novel approach for the diagnosis and therapy of CYP2J2-related vascular inflammation and cancer.

Protective effect of Rhein against vancomycin-induced nephrotoxicity through regulating renal transporters and Nrf2 pathway.

Vancomycin (VCM)'s nephrotoxicity limits its application and therapeutic efficiency. The aim of this study was to determine the protective effect of rhein against VCM-induced nephrotoxicity (VIN). VIN models were established in rats and NRK-52E cells. Rhein up-regulated the expressions of renal organic anion transporter (Oat) 1, Oat3, organic cation transporter 2 (Oct2), multidrug resistance-associated protein 2 (Mrp2), mammal multidrug and toxin extrusion proteins 1 (Mate 1) and P-glycoprotein (P-gp) to facilitate the efflux of plasma creatinine, blood urea nitrogen (BUN), and plasma indoxyl sulfate. Rhein increased the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) to regulate the expression of Mrp2, P-gp, and Mate 1. The increased level of superoxide dismutase (SOD), decreased level of malondialdehyde (MDA) and reduced number of apoptosis cells were observed after treatment of rhein. Rhein decreased the number of apoptosis cells as well as increased the expression of B-cell lymphoma-2 (Bcl-2) and decreased expressions of Bcl-2-like protein 4 (Bax). ML385, as a typical inhibitor of Nrf2, reversed the protective effects of rhein in cells. Rhein oriented itself in the site of Keap1, inhibiting the Keap1-Nrf2 interaction. Rhein ameliorated VIN mainly through regulating the expressions of renal transporters and acting on Nrf2 pathway.

Rational Design of a Two-Photon Fluorescent Probe for Human Cytochrome†P450 3A and the Visualization of Mechanism-Based Inactivation.

Mechanism-based inactivation (MBI) can mediate adverse reactions and hepatotoxicity from drugs, which is a result of their conversion into highly reactive metabolites catalyzed by enzymes such as cytochrome P450 3A (CYP3A). In the present research, we optimized the key interaction domain of the fluorophore with the target protein to develop a two-photon fluorescent probe for CYP3A that is involved in the metabolism of more than half of all clinical drugs. The developed BN-1 probe exhibited appropriate selectivity and sensitivity for the semi-quantitative detection and imaging of endogenous CYP3A activity in various living systems, thereby providing a high-throughput screening system enabling evaluation of MBI-associated hepatotoxicity by CYP3A. Using BN-1 as a fluorescent molecular tool facilitates the efficient discovery and characterization of CYP3A-induced MBI in natural systems.

Puerarin sensitized K562/ADR cells by inhibiting NF-κB pathway and inducing autophagy.

Puerarin is an isoflavone isolated from Pueraria lobata (Willd.) Ohwi. In the present study, reversal effect and underlying mechanisms of puerarin on multidrug resistance (MDR) were investigated in K562/ADR cells. K562/ADR cells exhibited adriamycin (ADR) resistance and higher levels of MDR1 expression compared with K562 cells. Puerarin enhanced the chemosensitivity of K562/ADR cells and increased the ADR accumulation in K562/ADR cells. The expression levels of MDR1 were down-regulated by puerarin in K562/ADR cells. Luciferase reporter assay further demonstrated the inhibitory effect of puerarin on TNF-α-induced NF-κB activation. The phosphorylation of IκB-α was significantly suppressed by puerarin. In silico docking analyses suggested that puerarin well matched with the active sites of IκB-α. Moreover, a large number of autophagosomes were found in the cytoplasm of K562/ADR cells after puerarin treatment. The significant increase in LC3-II and beclin-1 was also observed, indicating autophagy induction by puerarin in K562/ADR cells. Puerarin induced cell cycle arrest and apoptosis in K562/ADR cells. Finally, puerarin inhibited phosphorylation of Akt and JNK. In conclusion, puerarin-sensitized K562/ADR cells by downregulating MDR1 expression via inhibition of NF-κB pathway and autophagy induction via Akt inhibition.

Alisma genus: Phytochemical constituents, biosynthesis, and biological activities.

The genus Alisma contains 11 species distributed worldwide, of which at least two species (A. orientale [Sam.] Juzep. and A. plantago-aquatica Linn.) have been used as common herbal medicines. Secondary metabolites obtained from the genus Alisma are considered to be the material basis for the various biological functions and medicinal applications. In this review, we mainly focused on the recent investigations of secondary metabolites from plants of the genus Alisma and their biological activities, with the highlighting on the diversity of the chemical structures, the biosynthesis of interesting secondary metabolites, the biological activities, and the relationships between structures and bioactivities.

Organic anion transporters and PI3K-AKT-mTOR pathway mediate the synergistic anticancer effect of pemetrexed and rhein.

The aim of this study was to explore whether rhein could enhance the effects of pemetrexed (PTX) on the therapy of non-small-cell lung cancer (NSCLC) and to clarify the associated molecular mechanism. Our study shows that rhein in combination with PTX could obviously increase the systemic exposure of PTX in rats, which would be mediated by the inhibition of organic anion transporters (OATs). Furthermore, the toxicity of PTX was significantly raised by rhein in A549 cells in a concentration-dependent manner. Concomitant administration of rhein and PTX-induced cell apoptosis compared with PTX alone in flow cytometry assays, which was further validated by the protein expressions of the apoptotic markers B-cell lymphoma-2/Bcl-2-associated x (Bcl-2/Bax) and Cleaved-Caspase3 (Cl-Caspase3). Meanwhile, the results of monodansylcadaverine (MDC) dyeing experiments showed that PTX-induced autophagy could be enhanced by combination therapy with rhein in A549 cells. Western blot analysis indicated that the synergistic effect of rhein on PTX-mediated autophagy may be interrelated to PI3K-AKT-mTOR pathway inhibition and to the enhancement of p-AMPK and light chain 3-II (LC3-II) protein levels. From these findings, it could be surmised that rhein enhanced the antitumor activity of PTX through influencing autophagy and apoptosis by modulating the PI3K-AKT-mTOR pathway and Bcl-2 family of proteins in A549 cells. Our findings demonstrated that the potential application of rhein as a candidate drug in combination with PTX is promising for treatment of the human lung cancer.

Inula japonica ameliorated bleomycin-induced pulmonary fibrosis via inhibiting soluble epoxide hydrolase.

Pulmonary fibrosis is a progressive, irreversible, and fatal fibrotic lung disease with a high mortality and morbidity, and commonly nonresponsive to conventional therapy. Inula japonica Thunb. is a traditional Chinese medicine, known as "Xuan Fu Hua" in Chinese, and has been widely applied to relieve cough and dyspnea and eliminate retained phlegm with a long history. In this study, we aimed to evaluate the anti-fibrosis effect and action mechanism of I. japonica extract (IJE) for the treatment of bleomycin (BLM)-induced pulmonary fibrosis in mice. IJE treatment significantly restored BLM-induced alterations in body weight loss and lung function decline, decreased the collagen deposition induced by BLM in lung tissues, and inhibited fibrotic and inflammatory factors, such as α-SMA, TGF-ß1, TNF-α, IL-6, COX-2, NF-κB, and GSK3ß, in a dose-dependent manner. We found that IJE could enhance the concentration of 8,9-epoxyeicosatrienoic acid (8,9-EET) and decrease concentrations of 8,9-dihydroxyeicosatrienoic acid (8,9-DHET), 11,12-DHET, and 14,15-DHET in BLM-induced mice. Meanwhile, IJE suppressed protein and mRNA expression levels of soluble epoxide hydrolase (sEH), and significantly displayed the inhibition of sEH activity with an IC50 value of 0.98 µg/mL. Our results indicated that IJE exerted remarkable anti-fibrosis effect on BLM-induced pulmonary fibrosis in mice via inhibiting sEH activity, resulting in the regulation of GSK3ß signaling pathway. Our findings revealed the underlying action mechanism of I. japonica, and suggested that I. japonica could be regarded as a candidate resource for the treatment of pulmonary fibrosis.

Targeting renal OATs to develop renal protective agent from traditional Chinese medicines: Protective effect of Apigenin against Imipenem-induced nephrotoxicity.

Imipenem (Imp) is a widely used broad-spectrum antibiotic. However, renal adverse effects limit its clinical application. We previously reported that organic anion transporters (OATs) facilitated the renal transport of Imp and contributed its nephrotoxicity. Natural flavonoids exhibited renal protective effect. Here, we aimed to develop potent OAT inhibitors from traditional Chinese medicines (TCMs) and to evaluate its protective effect against Imp-induced nephrotoxicity. Among 50 TCMs, Tribuli Fructus, Platycladi Cacumen, and Lycopi Herba exhibited potent inhibition on OAT1/3. After screening their main components, Apigenin strongly inhibited Imp uptake by OAT1/3-HEK293 cells with IC50 values of 1.98 ± 0.36 µM (OAT1) and 2.29 ± 0.88 µM (OAT3). Moreover, Imp exhibited OAT1/3-dependent cytotoxicity, which was alleviated by Apigenin. Furthermore, Apigenin ameliorated Imp-induced nephrotoxicity in rabbits, and reduced the renal secretion of Imp. Apigenin inhibited intracellular accumulation of Imp and sequentially decreased the nephrocyte toxicity in rabbit primary proximal tubule cells (rPTCs). Apigenin, a flavone widely distributed in TCMs, was a potent OAT1/3 inhibitor. Through OAT inhibition, at least in part, Apigenin decreased the renal exposure of Imp and consequently protected against the nephrotoxicity of Imp. Apigenin can be used as a promising agent to reduce the renal adverse reaction of Imp in clinic.

ß-Glucuronidase- and OATP2B1-mediated drug interaction of scutellarin in Dengzhan Xixin Injection: A formulation aspect.

Scutellarin is the major and active constituent of Dengzhan Xixin Injection (DZXX), a traditional Chinese medicine prepared from the aqueous extract of Erigeron breviscapus and widely used for the treatment of various cerebrovascular diseases in clinic. In present study, the possible pharmacokinetic differences of scutellarin after intravenous administration of scutellarin alone or DZXX were explored. Additional, the potential roles of ß-glucuronidase (GLU) and OATP2B1 in drug-drug interaction (DDI) between scutellarin and constituents of DZXX were further evaluated in vitro. The plasma concentration, urinary and biliary excretion of scutellarin in rats after administration of DZXX, were significantly higher than those received scutellarin, while pharmacokinetic profile of Apigenin 7-O-glucuronide (AG) in rats was similar no matter AG or DZXX group. Furthermore, higher concentration in brain and plasma, however, lower level of scutellarin in intestine were observed after intravenous administration of DZXX. Finally, AG and caffeoylquinic acid esters were found to significantly inhibit GLU and OATP2B1 in vitro, which might explain, at least in part, the pharmacokinetic DDI between scutellarin and other chemical constituents in DZXX. The findings provided deep insight into the prescription-formulating principle in DZXX for treating the cerebrovascular diseases.

Combination of dihydromyricetin and ondansetron strengthens antiproliferative efficiency of adriamycin in K562/ADR through downregulation of SORCIN: A new strategy of inhibiting P-glycoprotein.

Though the advancement of chemotherapy drugs alleviates the progress of cancer, long-term therapy with anticancer agents gradually leads to acquired multidrug resistance (MDR), which limits the survival outcomes in patients. It was shown that dihydromyricetin (DMY) could partly reverse MDR by suppressing P-glycoprotein (P-gp) and soluble resistance-related calcium-binding protein (SORCIN) independently. To reverse MDR more effectively, a new strategy was raised, that is, circumventing MDR by the coadministration of DMY and ondansetron (OND), a common antiemetic drug, during cancer chemotherapy. Meanwhile, the interior relation between P-gp and SORCIN was also revealed. The combination of DMY and OND strongly enhanced antiproliferative efficiency of adriamycin (ADR) because of the increasing accumulation of ADR in K562/ADR-resistant cell line. DMY could downregulate the expression of SORCIN and P-gp via the ERK/Akt pathways, whereas OND could not. In addition, it was proved that SORCIN suppressed ERK and Akt to inhibit P-gp by the silence of SORCIN, however, not vice versa. Finally, the combination of DMY, OND, and ADR led to G2/M cell cycle arrest and apoptosis via resuming P53 function and restraining relevant proteins expression. These fundamental findings provided a promising approach for further treatment of MDR.

Molecular Design Strategy to Construct the Near-Infrared Fluorescent Probe for Selectively Sensing Human Cytochrome P450 2J2.

Cytochrome P450 2J2 (CYP2J2), a key enzyme responsible for oxidative metabolism of various xenobiotics and endogenous compounds, participates in a diverse array of physiological and pathological processes in humans. Its biological role in tumorigenesis and cancer diagnosis remains poorly understood, owing to the lack of molecular tools suitable for real-time monitoring CYP2J2 in complex biological systems. Using molecular design principles, we were able to modify the distance between the catalytic unit and metabolic recognition moiety, allowing us to develop a CYP2J2 selective fluorescent probe using a near-infrared fluorophore ( E)-2-(2-(6-hydroxy-2, 3-dihydro-1 H-xanthen-4-yl)vinyl)-3,3-dimethyl-1-propyl-3 H-indol-1-ium iodide (HXPI). To improve the reactivity and isoform specificity, a self-immolative linker was introduced to the HXPI derivatives in order to better fit the narrow substrate channel of CYP2J2, the modification effectively shortened the spatial distance between the metabolic moiety ( O-alkyl group) and catalytic center of CYP2J2. After screening a panel of O-alkylated HXPI derivatives, BnXPI displayed the best combination of specificity, sensitivity and applicability for detecting CYP2J2 in vitro and in vivo. Upon O-demethylation by CYP2J2, a self-immolative reaction occurred spontaneously via 1,6-elimination of p-hydroxybenzyl resulting in the release of HXPI. Allowing BnXPI to be successfully used to monitor CYP2J2 activity in real-time for various living systems including cells, tumor tissues, and tumor-bearing animals. In summary, our practical strategy could help the development of a highly specific and broadly applicable tool for monitoring CYP2J2, which offers great promise for exploring the biological functions of CYP2J2 in tumorigenesis.

Gambogic acid attenuates liver fibrosis by inhibiting the PI3K/AKT and MAPK signaling pathways via inhibiting HSP90.

Gambogic acid (GA), a major ingredient of Garcinia hanburryi, is known to have diverse biological effects. The present study was designed to evaluate the anti-fibrotic effects of GA on hepatic fibrosis and reveal its underlying mechanism. We investigated the anti-fibrotic effect of GA on dimethylnitrosamine and bile duct ligation induced liver fibrosis in rats in vivo. The rat and human hepatic stellate cell lines (HSCs) lines were chose to evaluate the effect of GA in vitro. Our results indicated that GA could significantly ameliorate liver fibrosis associated with improving serum markers, decrease in extracellular matrix accumulation and HSCs activation in vivo. GA significantly inhibited the proliferation of HSC cells and induced the cell cycle arrest at the G1 phase. Moreover, GA triggered autophagy at early time point and subsequent initiates mitochondrial mediated apoptotic pathway resulting in HSC cell death. The mechanism of GA was related to inhibit heat shock protein 90 (HSP90) and degradation of the client proteins inducing PI3K/AKT and MAPK signaling pathways inhibition. This study demonstrated that GA effectively ameliorated liver fibrosis in vitro and in vivo, which provided new insights into the application of GA for liver fibrosis.

Uncarialins A-I, Monoterpenoid Indole Alkaloids from Uncaria rhynchophylla as Natural Agonists of the 5-HT1A Receptor.

Nine new monoterpenoid indole alkaloids, uncarialins A-I (1-9), were isolated from Uncaria rhynchophylla as well as 14 known analogues (10-23). Their structures were determined by HRESIMS, 1D and 2D NMR, and experimental and calculated electronic circular dichroism data. Compounds 5, 7, 15, and 22 displayed significant agonistic effects against the 5-HT1A receptor with EC50 values of 2.2 ± 0.1, 0.1 ± 0.1, 1.6 ± 0.3, and 2.0 ± 0.5 µM, respectively. The mechanisms of action of these four compounds with the 5-HT1A receptor were investigated by molecular docking, and the results suggested that amino acid residues Asp116, Thr196, Asn386, and Tyr390 played critical roles in the observed activity of the above-mentioned compounds.

α-Pyrones, secondary metabolites from fungus Cephalotrichum microsporum and their bioactivities.

Cephalotrichum microsporum (SYP-F 7763) was a fungus isolated from the rhizosphere soil of traditional Chinese medicine Panax notoginseng. The EtOAc extract of Cephalotrichum microsporum cultivated on sterilized moistened-rice medium was separated by various chromatographic techniques, which yielded 11 metabolites (1-11) of this fungus. On the basis of the widely spectroscopic data, the chemical structures of isolated metabolites were determined, most of which were α-pyrones, including 5 compounds (4-7, and 10) unreported. In the anti-bacterial bioassay, compound 1 displayed significant inhibitory effects on three pathogenic bacteria, MR S. aureus, S. aureus, and B. cereus. α-Pyrones 2, 3, and 5-7 also displayed moderate inhibitory effects on MR S. aureus, S. aureus, and B. subtilis, which could be the major anti-bacterial constituents of Cephalotrichum microsporum. Additionally, compounds 1, 4, and 5 displayed significant cytotoxicity on five human cancer cell lines, with the IC50 values < 20 µM, which are more effective than positive control 5-fluorouracil. Therefore, α-pyrones were important secondary metabolites of Cephalotrichum microsporum, which displayed anti-bacterial and anti-tumor activities.