Biosynthesis of Enfumafungin-type Antibiotic Reveals an Unusual Enzymatic Fusion Pattern and Unprecedented C-C Bond Cleavage.

Enfumafungin-type antibiotics, represented by enfumafungin and fuscoatroside, belong to a distinct group of triterpenoids derived from fungi. These compounds exhibit significant antifungal properties with ibrexafungerp, a semisynthetic derivative of enfumafungin, recently gaining FDA's approval as the first oral antifungal drug for treating invasive vulvar candidiasis. Enfumafungin-type antibiotics possess a cleaved E-ring with an oxidized carboxyl group and a reduced methyl group at the break site, suggesting unprecedented C-C bond cleavage chemistry involved in their biosynthesis. Here, we show that a 4-gene (fsoA, fsoD, fsoE, fsoF) biosynthetic gene cluster is sufficient to yield fuscoatroside by heterologous expression in Aspergillus oryzae. Notably, FsoA is an unheard-of terpene cyclase-glycosyltransferase fusion enzyme, affording a triterpene glycoside product that relies on enzymatic fusion. FsoE is a P450 enzyme that catalyzes successive oxidation reactions at C19 to facilitate a C-C bond cleavage, producing an oxidized carboxyl group and a reduced methyl group that have never been observed in known P450 enzymes. Our study thus sets the important foundation for the manufacture of enfumafungin-type antibiotics using biosynthetic approaches.

Discovery of a Potent Antiosteoporotic Drug Molecular Scaffold Derived from Angelica sinensis and Its Bioinspired Total Synthesis.

Angelica sinensis, commonly known as Dong Quai in Europe and America and as Dang-gui in China, is a medicinal plant widely utilized for the prevention and treatment of osteoporosis. In this study, we report the discovery of a new category of phthalide from Angelica sinensis, namely falcarinphthalides A and B (1 and 2), which contains two fragments, (3R,8S)-falcarindiol (3) and (Z)-ligustilide (4). Falcarinphthalides A and B (1 and 2) represent two unprecedented carbon skeletons of phthalide in natural products, and their antiosteoporotic activities were evaluated. The structures of 1 and 2, including their absolute configurations, were established using extensive analysis of NMR spectra, chemical derivatization, and ECD/VCD calculations. Based on LC-HR-ESI-MS analysis and DFT calculations, a production mechanism for 1 and 2 involving enzyme-catalyzed Diels-Alder/retro-Diels-Alder reactions was proposed. Falcarinphthalide A (1), the most promising lead compound, exhibits potent in vitro antiosteoporotic activity by inhibiting NF-κB and c-Fos signaling-mediated osteoclastogenesis. Moreover, the bioinspired gram-scale total synthesis of 1, guided by intensive DFT study, has paved the way for further biological investigation. The discovery and gram-scale total synthesis of falcarinphthalide A (1) provide a compelling lead compound and a novel molecular scaffold for treating osteoporosis and other metabolic bone diseases.

Two new Nb-oxide indole alkaloids with ß-hematin inhibitory activity from the stems and leaves of Rauvolfia dichotoma.

Rauvolfia dichotoma, a shrub of Apocynaceae, was collected from the Islands of SAO Tome and Principe and cultivated locally for medicinal purpose. Phytochemical investigation of 95% ethanol extract from the stems and leaves of R. dichotoma led to the isolation of two new Nb-oxide indole alkaloids, namely Nb-oxide-mitoridine (1) and Nb-oxide-raucaffricine (2), together with two known alkaloids (3-4) and eleven known lignans (5-15). Their chemical structures were elucidated by extensive NMR and HR-ESI-MS data analysis. All compounds (except 13) were tested for their ß-hematin inhibitory activity. Compounds 2, 4, 14, and 15 showed certain inhibitory activity, indicating that they may have an antimalarial effect.

Thirteen new peptaibols with antimicrobial activities from Trichoderma sp.

From the fungus Trichoderma sp., we isolated seven novel 18-residue peptaibols, neoatroviridins E-K (1-7), and six new 14-residue peptaibols, harzianins NPDG J-O (8-13). Additionally, four previously characterized 18-residue peptaibols neoatroviridins A-D (14-17) were also identified. The structural configurations of the newly identified peptaibols (1-13) were determined by comprehensive nuclear magnetic resonance (NMR) and high-resolution electrospray ionization tandem mass spectrometry (HR-ESI-MS/MS) data. Their absolute configurations were further determined using Marfey's method. Notably, compounds 12 and 13 represent the first 14-residue peptaibols containing an acidic amino acid residue. In antimicrobial assessments, all 18-residue peptaibols (1-7, 14-17) exhibited moderate inhibitory activities against Staphylococcus aureus 209P, with minimum inhibitory concentration (MIC) values ranging from 8-32 µg·mL-1. Moreover, compound 9 exhibited moderate inhibitory effect on Candida albicans FIM709, with a MIC value of 16 µg·mL-1.

Eremophilane and cadinane sesquiterpenoids from the fruits of Alpinia oxyphylla and their anti-inflammatory activities.

The fruits of Alpinia oxyphylla have been used for centuries in China as both edible resources and traditional Chinese medicine. In order to identify structurally interesting and bioactive constituents from the fruits of A. oxyphylla, bioassay-guided fractionation and purification of the crude extracts were performed, which led to the isolation of 38 sesquiterpenoids, including six previously undescribed eremophilane sesquiterpenoids (1-6), six new cadinane sesquiterpenoids (23-24, 26-29), and 26 known analogues (7-22, 25 and 31-38). The structures of these compounds were elucidated by comprehensive spectroscopic data analysis, single crystal X-ray diffraction, quantum chemistry calculations (13C-NMR and ECD), and Mo2(OAc)4 reaction. Several of the isolated compounds (8, 13, 17, 18, 30, 31 and 35) showed moderate to strong inhibition of the secretion of cytokines (NO, TNF-α and IL-6) in LPS-stimulated BV-2 cells. Furthermore, western blot, immunofluorescence, and real-time PCR assays indicated that 18 could down-regulate the mRNA levels of TNF-α, IL-6, COX-2, and iNOS and the protein expression of COX-2 and iNOS. Meanwhile, 18 was able to partially inhibit the phosphorylation of ERK1/2, JNK, and p38. Thus, the discovery of structurally diverse anti-inflammatory sesquiterpenoids from the fruits of A. oxyphylla in this study could benefit the further development and utilization of this plant.

Cordythiazole A, the first member of thiazole alkaloids from Chinese cordyceps, with α-glucosidase inhibitory activity.

Chinese cordyceps, also known as Dong-Chong-Xia-Cao, is widely recognized as a famous precious tonic herb, and used as traditional Chinese medicine for centuries. It is mainly used for regulating the immune system and improving functions of the lung and kidney, with anti-tumor, anti-inflammatory, and anti-diabetic activities. Due to its rarity and preciousness, a few chemical components are isolated and identified. Moreover, most of them are common chemical components and widely distributed in other natural resources, such as nucleosides, sterols, fatty acids, sugar alcohols, and peptides. Therefore, a large number of active substances of Chinese cordyceps is still unclear. During our search for chemical constituents of Chinese cordyceps, a new thiazole alkaloid, cordythiazole A (1), was isolated and identified. Its structure was elucidated by comprehensive spectroscopic analysis and single-crystal X-ray diffraction analysis. This is the first report of the presence of thiazole alkaloid in Chinese cordyceps, which adds a new class of metabolite of Chinese cordyceps. Furthermore, a putative biosynthesis pathway of cordythiazole A was proposed based on possible biogenic precursor, genes, and literatures. In addition, it showed α-glucosidase inhibitory activity with potency close to that of acarbose. The discovery of cordythiazole A with α-glucosidase inhibitory activity adds a new class of potential anti-diabetes ingredient in Chinese cordyceps.

An integrated strategy by absorbed component characterization, pharmacokinetics, and activity evaluation for identification of potential nephroprotective substances in Zhu-Ling decoction.

An efficient strategy for the identification of potential nephroprotective substances in Zhu-Ling decoction has been established with the integration of absorbed components characterization, pharmacokinetics, and activity evaluation. A qualitative method was developed to characterize the chemical constituents absorbed components in vivo of Zhu-Ling decoction by using ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry. A quantitative method was established and validated for the simultaneous determination of eight compounds in rat plasma by using ultra-performance liquid chromatography-triple quadruple tandem mass spectrometry. Finally, the nephroprotective activities of absorbed components with high exposure were assessed by cell survival rate, superoxide dismutase, and malondialdehyde activities in hydrogen peroxide-induced Vero cells. As a result, 111 compounds in Zhu-Ling decoction and 36 absorbed components were identified in rat plasma and urine, and poricoic acid A, poricoic acid B, alisol A, 16-oxo-alisol A, and dehydro-tumulosic acid had high exposure levels in rat plasma. Finally, poricoic acid B, poricoic acid A, 16-oxo-alisol A, and dehydro-tumulosic acid showed remarkable nephroprotective activity against Vero cells damage induced by hydrogen peroxide. Besides, superoxide dismutase and malondialdehyde activities were obviously regulated in hydrogen peroxide-induced Vero cells by treatment with the four compounds mentioned above. Therefore, these four compounds were considered to be effective substances of Zhu-Ling decoction due to their relatively high exposure in vivo and biological activity. This study provided a chemical basis for the action mechanism of Zhu-Ling decoction in the treatment of chronic kidney diseases.

One undescribed glycoside benzofuran derivative and a new p-hydroxybenzoate glycoside from the leaves of Illicium dunnianum Tutcher.

One undescribed benzofuran derivative (illiciumphenolicacid A, 1) and one new phenolic glycoside (illiciumphenolicacid B, 2), together with six known compounds (3-8) were isolated from the leaves of Illicium dunnianum Tutcher. Their structures were elucidated by detailed spectroscopic data (UV, IR, HR-ESI-MS, 1D and 2D NMR). In addition, we determined the α-glucosidase inhibitory activity of the isolates in vitro using spectrophotometric methods. Compared with the positive control acarbose (IC50 306.2 ± 4.1 µM), compounds 1-8 were shown to be moderate potential α-glucosidase inhibitory activity with IC50 values in the range 380-655 µM.

Isolation of new compounds related to xyloketals biosynthesis implies an alternative pathway for furan-fused-chromene formation.

In fungi, there is a rare group of natural products harboring the 2,3,3a,9a-tetrahydro-4H-furo[2,3-b]chromene skeleton, represented by xyloketal B, which display a wide range of biological activities and have drawn significant attention. In this work, four new analogues simpliketals A-D (1-4), as well as two other new compounds simplilactones A and B (5 and 6), were isolated from Simplicillium sp. AHK071-01. Their structures were elucidated by extensive NMR spectroscopic methods, 13C NMR calculation, single-crystal X-ray diffraction, and ECD calculation. In addition, five known compounds (7-11) including alboatrin (7) were also obtained. Based on the structural similarity of the above compounds, we inferred that compounds 5, 6, and 8-11 might be biosynthetically related with 1-4 and 7, which allowed us to propose an alternative biosynthetic route to generate the furan-fused chromene skeleton of this class of compounds, instead of a previously presumed polyketide-terpenoid hybrid pathway. Finally, cytotoxicity assays showed that 1-4 exhibited weak inhibitory activity on PANC-1 cells and that 2 and 3 possessed moderate activity against SH-SY5Y cells.

Nur77 Serves as a Potential Prognostic Biomarker That Correlates with Immune Infiltration and May Act as a Good Target for Prostate adenocarcinoma.

Prostate adenocarcinoma (PRAD) is the most frequent malignancy, and is the second leading cause of death due to cancer in men. Thus, new prognostic biomarkers and drug targets for PRAD are urgently needed. As we know, nuclear receptor Nur77 is important in cancer development and changes in the tumor microenvironment; whereas, the function of Nur77 in PRAD remains to be elucidated. The TCGA database was used to explore the Nur77 expression and its role in the prognosis of PRAD. It was shown that Nur77 was down regulated in PRAD, and low Nur77 expression was correlated with advanced clinical pathologic characteristics (high grade, histological type, age) and poor prognosis. Furthermore, key genes screening was examined by univariate Cox analysis and Kaplan-Meier survival. Additionally, Nur77 was closely related to immune infiltration and some anti-tumor immune functions. The differentially expressed genes (DEGs) were presented by protein-protein interaction (PPI) network analysis. Therefore, the expression level of Nur77 might help predict the survival of PRAD cases, which presents a new insight and a new target for the treatment of PRAD. In vitro experiments verified that natural product malayoside targeting Nur77 exhibited significant therapeutic effects on PRAD and largely induced cell apoptosis by up-regulating the expression of Nur77 and its mitochondrial localization. Taken together, Nur77 is a prognostic biomarker for patients with PRAD, which may refresh the profound understanding of PRAD individualized treatment.

Biosynthetic characterization of the antifungal fernane-type triterpenoid polytolypin for generation of new analogues via combinatorial biosynthesis.

Fernane-type triterpenoids are a small group of natural products mainly found in plants and fungi with a wide range of biological activities. Polytolypin is a representative fernane-type triterpenoid from fungi and possesses potent antifungal activity. So far, biosynthesis of fungal-derived fernane-type triterpenoids has not been characterized, which hinders the expansion of their structural diversity using biosynthetic approaches. Herein, we identified the biosynthetic gene cluster of polytolypin and elucidated its biosynthetic pathway through heterologous expression in Aspergillus oryzae NSAR1, which involves a new triterpene cyclase for the biosynthesis of the hydrocarbon skeleton motiol, followed by multiple oxidations via three P450 enzymes. Moreover, two new triterpene cyclases for the biosynthesis of two other fernane-type skeletons isomotiol and fernenol were identified from fungi, and were individually co-expressed with the three P450 enzymes involved in polytolypin biosynthesis. These studies led to the generation of 13 fernane-type triterpenoids including eight new compounds, and two of them showed stronger antifungal activity towards Candida albicans FIM709 than polytolypin.

Gardenia jasminoides Extract GJ-4 Alleviates Memory Deficiency of Vascular Dementia in Rats through PERK-Mediated Endoplasmic Reticulum Stress Pathway.

Endoplasmic reticulum stress (ERS) is involved in the pathological process of vascular dementia (VD). GJ-4 is extracted from Gardenia jasminoides J. Ellis and has been reported to have protective roles in ischemia-related brain damage. However, the role of GJ-4 in ERS has not been elucidated. We established a VD rat model through bilateral common carotid arteries occlusion (2-VO). The rats were intragastrically administrated with GJ-4 (10, 25, and 50[Formula: see text]mg/kg) and nimodipine (10[Formula: see text]mg/kg). Data from a Morris water maze test showed that GJ-4 could significantly alleviate learning and memory deficits in VD rats. Nissl and cleaved caspase-3 staining revealed that GJ-4 can inhibit apoptosis and thus exert a protective role in the brain of 2-VO rats. Western blot results suggested that GJ-4 significantly reduced ERS-related protein expression and inhibited apoptosis through suppression of the PERK/eIF2[Formula: see text]/ATF4/CHOP signaling pathway. For in vitro studies, the oxygen-glucose deprivation (OGD) SH-SY5Y model was employed. Western blot and Hoechst 33342/PI double staining were utilized to explore the effects of crocetin, the main active metabolite of GJ-4. Like GJ-4 in vivo, crocetin in vitro also decreased ERS-related protein expression and inhibited the activation of the PERK/eIF2[Formula: see text]/ATF4/CHOP signaling pathway. Thus, crocetin exerted similar protective roles on OGD challenged SH-SY5Y cells in vitro. In summary, GJ-4 and crocetin reduce the ERS in the brain of VD rats and SY5Y cells subjected to OGD and inhibit neuronal apoptosis through suppression of the PERK/eIF2[Formula: see text]/ATF4/CHOP pathway, suggesting that GJ-4 may be useful for the treatment of VD.

Chemical and metabolic profiling of Codonopsis Radix extract with an integrated strategy using ultra-high-performance liquid chromatography coupled with mass spectrometry.

Codonopsis radix was commonly used as food materials or herbal medicines in many countries. However, the comprehensive analysis of chemical constituents, and in vivo xenobiotics of Codonopsis radix remain unclear. In the present study, an integrated strategy with feature-based molecular networking using ultra-high-performance liquid chromatography coupled with mass spectrometry was established to systematically screen the chemical constituents and the in vivo xenobiotics of Codonopsis radix. A step-by-step manner based on a composition database, visual structure classification, discriminant ions, and metabolite software prediction was proposed to overcome the complexities due to the similar structure of chemical constituents and metabolites of Codonopsis radix. As a result, 103 compounds were tentatively characterized, 20 of which were identified by reference standards. Besides, a total of 50 xenobiotics were detected in vivo, including 26 prototypes and 24 metabolites, while the metabolic features of the pyrrolidine alkaloids were elucidated for the first time. The metabolism reactions of pyrrolidine alkaloids and sesquiterpene lactones included oxidation, methylation, hydration, hydrogenation, demethylation, glucuronidation, and sulfation. This study provided a generally applicable approach to the comprehensive investigation of the chemical and metabolic profile of traditional Chinese medicine and offered reasonable guidelines for further screening of quality control indicators and pharmacodynamics mechanism of Codonopsis radix.

Two new chemical constituents from the leaves of Illicium dunnianum.

One new phenolic glycoside (1) and one new benzofuran derivative (2) were isolated from the leaves of Illicium dunnianum. The structures of these compounds were established by using comprehensive spectroscopic data analysis, including the 1D and 2D NMR, IR, HR-ESI-MS, electronic circular dichroism and comparison with literature data. All isolates were evaluated for the inhibition against the production of NO by LPS-stimulated RAW 264.7 macrophages.

Astramalabaricosides A-T, Highly Oxygenated Malabaricane Triterpenoids with Migratory Inhibitory Activity from Astragalus membranaceus var. mongholicus.

Twenty new malabaricane triterpenoids, astramalabaricosides A-T (1-20), were isolated from the roots of Astragalus membranaceus var. mongholicus (Astragali Radix). Their structures were determined by spectroscopic analysis, and the use of the circular dichroism exciton chirality method, quantum chemical calculations, and chemical methods. Malabaricane triterpenoids, an unusual group with the 6-6-5-tricyclic core, are distributed in plants (e.g., Simaroubaceae, Polypodiaceae, and Fabaceae), a marine sponge, and fungi, and their number obtained to date is limited. Compounds 1-20 were characterized as glycosides with a highly oxygenated side chain, and 13-20 were the first cyclic carbonate derivatives among the malabaricane triterpenoids. The stereocluster formed from the continuous hydroxylated chiral carbons in each highly oxygenated side chain and the 6-6-5-tricyclic core system were entirely segregated, and the independent identification of their stereoconfigurations required considerable effort. The migratory inhibitory and antiproliferative activities of 1-20 were evaluated by wound-healing and cell-viability assays, respectively. Most compounds showed significant migratory inhibitory activity, and a preliminary structure-activity relationship was developed. Malabaricane triterpenoids are being reported in the genus Astragalus for the first time.

Network pharmacology provides a systematic approach to understanding the treatment of ischemic heart diseases with traditional Chinese medicine.

BACKGROUND: The field of network pharmacology showed significant development. The concept of network pharmacology has many similarities to the philosophy of traditional Chinese medicine (TCM), making it suitable to understand the action mechanisms of TCM in treating complex diseases, such as ischemic heart diseases (IHDs). PURPOSE: This review summarizes the representative applications of network pharmacology in deciphering the mechanism underlying the treatment of IHDs with TCM. METHODS: In this report, we used "ischemic heart disease" OR "coronary heart disease" OR "coronary artery disease" OR "myocardial ischemia" AND ("network pharmacology" OR "systematic pharmacology") as keywords to search for publications from PubMed, the Web of Science, and Google Scholar databases and then analyzed the representative research reports that summarized and validated the active components and targets network of TCM in improving IHDs to show the advantages and deficiencies of network pharmacology applied in TCM research. RESULTS: The network pharmacology research indicated that HGF, PGF, MMP3, INSR, PI3K, MAPK1, SRC, VEGF, VEGFR-1, NO, eNOS, NO3, IL-6, TNF-α, and more are the main targets of TCM. Apigenin, 25S-macrostemonoside P, ginsenosides Re, Rb3, Rg3, SheXiang XinTongNing, colchicine, dried ginger-aconite decoction, Suxiao Xintong dropping pills, Ginseng-Danshen drug pair and Shenlian and more are the active ingredients, extracts, and formulations of TCM to ameliorate IHDs. These active compounds, extract, and formulations of TCM treat IHDs by delaying ventricular remodeling, reducing myocardial fibrosis, decreasing reactive oxygen species, regulating myocardial energy metabolism, ameliorating inflammation, mitigating apoptosis, and many other aspects. CONCLUSIONS: The network pharmacology supplies a novel research exemplification for understanding the treatment of IHDs with TCM. However, the application of network pharmacology in TCM studies is still at a superficial level. By rational combining artificial intelligence technology and network pharmacology, molecular biology, metabolomics, and other advanced theories and technologies, and systematically studying the metabolic process and the network among products, targets, and pathways of TCM from the clinical perspective may be a potential development trend in network pharmacology.

Pharmacokinetics, hepatic disposition, and heart tissue distribution of 14 compounds in rat after oral administration of Qi-Li-Qiang-Xin capsule via ultra-high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry.

In the present study, a specific and sensitive approach using ultra-high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry was developed and validated for the quantitative analysis of 14 constituents in rat plasma, liver, and heart. The method was fully validated and successfully applied to pharmacokinetic, hepatic disposition, and heart tissue distribution studies of 14 compounds after the oral administration of Qi-Li-Qiang-Xin capsule. Ginsenoside Rb1, alisol A, astragaloside IV, and periplocymarin were found to be highly exposed in rat plasma, while toxic components such as hypaconitine, mesaconitine, and periplocin had low circulation levels in vivo. Moreover, sinapine thiocyanate, neoline, formononetin, calycosin, and alisol A exhibited significant liver first-pass effects. Notably, high levels of alisol A, periplocymarin, benzoylmesaconine, and benzoylhypaconine were observed in the heart. Based on high exposure and appropriate pharmacokinetic features in the systemic plasma and heart, astragaloside IV, ginsenoside Rb1, periplocymarin, benzoylmesaconine, benzoylhypaconine, and alisol A can be considered as the main potentially effective components. Ultimately, the results provide relevant information for discovery of effective substances, as well as further anti-heart failure action mechanism investigations of Qi-Li-Qiang-Xin capsule.

Two new chemical constituents from the rhizomes of Actaea dahurica.

A new phenylpropanoid allopyranoside (1) and a new indolinone alkaloid (2) were isolated from the rhizomes of Actaea dahurica (syn. Cimicifuga dahurica). The structures of those two compounds were deduced as cimicifugaside F (1) and 3E,11E-(3-methyl-2-butenylidene acid)-2-indolinone-1-O-ß-d-glucopyranoside (2) by detailed analysis of their MS, 1D and 2D NMR data and comparison with literatures. Additionally, the isolates were evaluated for their inhibitory effects on the production of NO by LPS-stimulated RAW 264.7 macrophages.

Two new iridoid glycosides from the fruit of Gardenia jasminoides.

Two new iridoid glycosides, 2'-O-cis-coumaroylgardoside (1), and 6'-O-caffeoylioxide (2), were isolated from the fruit of Gardenia jasminoides. The structures of these compounds were elucidated based on spectroscopic analysis (HR-ESI-MS, NMR) and chemical methods. The anti-inflammatory activities of the isolates were evaluated by measuring their inhibitory effects on PGE2 production in LPS stimulated RAW 264.7 macrophages, compounds 1 and 2 could reduce PGE2 levels in LPS-activated RAW 264.7 macrophages with IC50 values of 121.4 and 83.38 µM, respectively.

Stachybotranes A-D, phenylspirodrimanes from the wetland fungus Stachybotrys chartarum with cytotoxic activities.

Four new phenylspirodrimanes, stachybotranes A-D (1-4), along with seven known analogues (5-11), were isolated from the extract of a wetland fungal strain Stachybotrys chartarum DTH12-9. The structures of new compounds were determined by spectroscopic analyses, X-ray crystallographic analysis, and the CD analysis of the in situ formed [Rh2(OCOCF3)4] complex. Compounds 1-3, 5-8, and 10 were evaluated for in vitro cytotoxicity against five human cancer cell lines, HL-60, SMMC-7721, A-549, MCF-7, and SW-480. Compounds 1, 2, and 7 exhibited moderate cytotoxic potency against various human cancer cell lines.