Five undescribed cyclopeptides from Cordyceps militaris.

Ustiloxins I-M (1-5), five undescribed cyclopeptides bearing a 15-membered macrocyclic skeleton, were isolated from Cordyceps militaris. The structures of 1 and 5 were identified by spectroscopic and crystallographic methods, whereas the structures of 2-4 were assigned by spectroscopic and computational approaches. Biological evaluation of all the compounds toward human triple-negative breast cancer cells revealed that compounds 4 and 5 are toxic with IC50 values of 64.29 µM and 28.89 µM, respectively.

Structurally Diverse Alkaloids with Anti-Renal-Fibrosis Activity from the Centipede Scolopendra subspinipes mutilans.

Twelve new alkaloids, scolopenolines A-L (1-7, 9-11, 13, 14), along with six known analogues, were isolated from Scolopendra subspinipes mutilans, identified by analysis of spectroscopic data and quantum chemical and computational methods. Scolopenoline A (1), a unique guanidyl-containing C14 quinoline alkaloid, features a 6/6/5 ring backbone. Scolopenoline B (2) is a novel sulfonyl-containing heterodimer comprising quinoline and tyramine moieties. Scolopenoline G (7) presents a rare C12 quinoline skeleton with a 6/6/5 ring system. Alkaloids 1, 8, 10, and 15-18 display anti-inflammatory activity, while 10 and 16-18 also exhibit anti-renal-fibrosis activity. Drug affinity responsive target stability and RNA-interference assays show that Lamp2 might be a potentially important target protein of 16 for anti-renal-fibrosis activity.

A dual mechanism with H2S inhibition and membrane damage of morusin from Morus alba Linn. against MDR-MRSA.

It's urgent to discover new antibiotics along with the increasing emergence and dissemination of multidrug resistant (MDR) bacterial pathogens. In the present investigation, morusin exhibited rapid bactericidal activity against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) by targeting the phospholipid of bacterial inner membrane, increasing membrane rigidity and disrupting bacterial homeostasis together with the membrane permeability, which caused fundamental metabolic disorders. Furthermore, morusin can also accumulate ROS, suppress H2S production, and aggravate oxidative damage in bacteria. Importantly, morusin also inhibited the spread of wounds and reduced the bacterial burden in the mouse model of skin infection caused by MRSA. It's a chance to meet the challenge of existing antibiotic resistance and avoid the development of bacterial resistance, given the multiple targets of morusin.

Undescribed indole lactones from Alstonia scholaris protecting hepatic cell damage.

Six previously undescribed rigidly monoterpenoid indole alkaloids, alstolactines F-K (1-6), were isolated from Alstonia scholaris. Among them, a pair of cage-like epimers, 1 and 2, featuring a rare 6/5/6/6/7 ring system, represent the first example of C5→C20-olide, while compound 3 possesses unique degraded C18 and C19. The structures of the isolates were established by multiple spectroscopic analyses, quantum computational chemistry methods, and X-ray diffraction. Furthermore, the expression levels of proteins including NLRP3, TLR4, P-p65, NF-ĸB, Notch-2, IL-18, P-p38, and p38 in LPS-induced human normal hepatocyte (LO2) cells could be significantly downregulated by compounds 1-6, which showed potent anti-inflammatory bioactivity.

New Lupanes from Alstonia scholaris Reducing Uric Acid Level.

Twelve lupanes including three new compounds named alstoscholarilups A-C (1: -3: ) were isolated from the leaves of Alstonia scholaris. Their structures were elucidated by spectroscopic analysis and ECD calculation. Structurally, compound 1: with a rare A ring-seco skeleton formed lactone and degraded C-3, while 2: with a 28-nor and 3: with a 29-nor-lupane skeleton supported the phytochemical diversity and novelty of the plant. Pharmacologically, compounds 4, 7: , and 10: reduced the serum uric acid (UA) levels of mice significantly.

Anomalous Klein tunneling in two-dimensional black phosphorus heterojunctions.

We investigate the role of heterojunctions of few-layer black phosphorus (BP) with band gap inversion in governing the quantum transport behaviors. Numerical results show that in the armchair junction, electron tunneling probability occurs under approximately normal incidence with its magnitude T > 0.5. More interestingly, when different band gaps are taken into account on two sides of this junction, the maximum transmission appears away from the center of the valley, leading to the occurrence of anomalous Klein tunneling. Such a result tends to be independent of the width and height of the potential barrier. On the other hand, in the zigzag junction, electron transmission arises in a larger range of angles, and perfect electron transmission (T = 1.0) or reflection appears under specific band gap configurations. These findings provide a new understanding for the study of Klein tunneling and anomalous Klein tunneling based on tunable band gap BP or other two-dimensional Dirac semimetals.

Nine pairs of undescribed enantiomers from the resin of Styrax tonkinensis (Pierre) Craib ex Hart with anti-inflammatory activity.

Nine pairs of undescribed enantiomers, (±)-styraxoids A-I (1-9), were isolated from the resin of Styrax tonkinensis, and their structures were assigned by spectroscopic and computational methods. Compounds (±)-1 are a pair of degraded lignans, and the remaining compounds (±)-(2-9) are phenylpropanoid skeletons. Compounds (±)-8 and (±)-9 feature a 1,3-dioxolane moiety. The biological evaluation showed that both enantiomers of 1 could inhibit LPS-induced INOS and COX-2 in RAW264.7 cells in a dose-dependent manner.

Jiangchuanmycin, a New Pyrrolizidine Analog from Streptomyces sp. YIM S01863.

Jiangchuanmycin (1), a new indole containing pyrrolizidine, and six known peptides (2-7) were obtained from the fermentation broth of a Streptomyces isolate collected from a sediment sample of Xingyun Lake, Jiangchuan, China. Their structures were elucidated on the detailed analysis of the HR-ESI-MS, 1D and 2D NMR, ECD, and X-ray crystallographic data. Jiangchuanmycin (1) presented weak inhibitory effects on cell lines of H1299, MHCC97H, HCT116 with the IC50 values of 97.6 µM, 98.6 µM and 40.6 µM, respectively.

Significant anti-inflammatory aziridine-containing indole alkaloids from the Chinese medicinal plant Alstonia scholaris.

Two unique windmill-like aziridine-containing indole alkaloids, possessing an unprecedented 6/5/5/6/6/5/3 rigid ring system and an unusual azabicyclo[3.1.0]hexane core, were isolated from Alstonia scholaris. Their structures were established by spectroscopy, X-ray diffraction, and electronic circular dichroism calculations. The novel compounds exhibited significant anti-inflammatory bioactivity in vitro and alleviated LPS-induced acute lung injury in mice.

Steroidal alkaloids from the roots of Veratrum stenophyllum.

Three new steroidal alkaloids, veratrasines A - C (1-3), along with ten known analogues (4-13) were isolated from the roots of Veratrum stenophyllum. Their structures were elucidated by NMR and HRESIMS data and comparison with the reported data in the literatures. A plausible biosynthetic pathway for 1 and 2 were proposed. Compounds 1, 3, and 8 showed moderate cytotoxic activity against MHCC97H and H1299 cell lines.

Relationship between peritoneal solute transport and dialysate inflammatory markers in peritoneal dialysis patients: A cross-sectional study.

BACKGROUND: The associated factors of peritoneal small solute transport was not fully understood. This research aimed to investigate the connection between dialysate inflammatory markers (e.g. macrophage migration inhibitory factor, MIF) in peritoneal dialysis (PD) effluent and peritoneal solute transport rate (PSTR) properties. SUBJECTS AND DESIGN: A total of 80 stable PD patients in the First ShaoYang Hospital were enrolled in present study. Overnight PD effluent and serum inflammatory markers including MIF, MCP-1, VEGF, IL-6, TNFα and TGFß were detected. Pearson correlation analysis and Logistic regression was performed to determine the risk factors for the increased PSTR. RESULTS: A trend toward increased values of MIF, MCP-1 and IL-6 in PD effluent was observed in subjects with high PSTR when compared with those with low PSTR. The Pearson correlation test showed that D/P Cr exhibited positive correlations with dialysis effluent MIF (r=0.32, p=0.01), MCP-1 (r=0.47, p=0.01), IL-6 (r=0.48, p=0.01). Conversely, no significant correlation was found between D/P Cr and TGF-ß (r=0.04, p=0.70), TNF-ɑ (r=0.22, p=0.05), VEGF (r=0.02, p=0.86) and serum inflammatory markers. In the unadjusted regression analysis, dialysis effluent MIF (OR 2.41), MCP-1 (OR 1.72), IL-6 (OR 1.55) were associated with high PSTR condition. Multivariate logistic regression analysis showed that the adjusted odds ratios (OR) of dialysis effluent MIF for high PSTR were 2.47 in all subjects (p=0.03). CONCLUSION: Elevated MIF, MCP-1 and IL-6 levels in PD effluent were associated with increased PSTR. Elevated dialysis effluent MIF levels was an independent risk factor for high PSTR in subjects with PD treatment.

Steroidal alkaloid with unprecedented triheterocyclic architecture.

Veratrazine A (1), a steroidal alkaloid with a unique 6/5/5 triheterocyclic scaffold as the side chain, was isolated from Veratrum stenophyllum, and its structure was established via spectroscopic analyses and X-ray diffraction. A plausible biosynthetic pathway for 1 is proposed. Bioassy exhibits moderate anti-inflammatory activities in vitro and in vivo.

The role of different macrophages-derived conditioned media in dental pulp tissue regeneration.

Macrophages have been reported to play important roles in tissue repair and regeneration. While it is known that macrophages are present in the dental pulp, their role in dental pulp regeneration is not fully understood. In the present study, we investigated the effects of different phenotype macrophages conditioned medium on the cellular behaviors of hDPSCs and their extracellular matrix (cell sheets) in vitro. Moreover, twenty-four root fragments inserted with cell sheets cultured with different conditioned media were placed into the back subcutaneous space of 6-8-week-old male BALB/c nude mouse. The regenerated tissues in the root fragments were assessed via histologic analysis after 8 weeks of transplantation. M2 macrophages could promote the proliferation, migration, and osteogenic differentiation of hDPSCs. Dental pulp-like tissue with an odontoblast-like layer lining the dentinal surface and well-arranged collagen fibers was harvested in root fragment combined with M2 conditioned medium cultured cell sheet, whereas a large amount of calcium salt deposition and disorganization of collagen fibers were observed in root fragments combined with M1 conditioned medium cultured cell sheet. Therefore, promoting the transformation of M1 into M2 macrophage in dental pulp tissue regeneration may be a potential way for dental pulp regeneration via functional healing.

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.

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.

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.

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.

Potent Antihyperuricemic Triterpenoids Based on Two Unprecedented Scaffolds from the Leaves of Alstonia scholaris.

Two rearranged triterpenoids, representing new subtypes of pentacyclic triterpenoids, with unique 6/6/6/7/5 and 6/6/5/6/6/6 ring systems were isolated from Alstonia scholaris. Their structures were established by spectroscopic analysis, single-crystal X-ray diffraction, and electronic circular dichroism calculations. Both compounds exhibited potent antihyperuricemic bioactivity in vitro and in vivo.

Neferine Protects against Hypoxic-Ischemic Brain Damage in Neonatal Rats by Suppressing NLRP3-Mediated Inflammasome Activation.

Hypoxic-ischemic encephalopathy (HIE) is recognized as the main cause of neonatal death, and efficient treatment strategies remain limited. Given the prevalence of HIE and the associated fatality, further studies on its pathogenesis are warranted. Oxidative stress and neuroinflammatory injury are two important factors leading to brain tissue injury and nerve cell loss in HIE. Neferine, an alkaloid extracted from lotus seed embryo, exerts considerable effects against several diseases such as cancers and myocardial injury. In this study, we demonstrated the neuroprotective effect of neferine on HIE and hypothesized that it involves the inhibition of neuronal pyroptosis, thereby ameliorating neurological inflammation and oxidative stress. We demonstrated that the mRNA levels of proteins associated with pyroptosis including caspase-1, the caspase adaptor ASC, gasdermin D, interleukin- (IL-) 18, IL-1ß, and some inflammatory factors were significantly increased in neonatal HIBD model rats compared to those in the control group. The increase in these factors was significantly suppressed by treatment with neferine. We stimulated PC12 cells with CoCl2 to induce neuronal HIBD in vitro and investigated the relationship between neferine and pyroptosis by altering the expression of the NLRP3 inflammasome. The overexpression of NLRP3 partially reversed the neuroprotective effect of neferine on HIBD, whereas NLRP3 knockdown further inhibited caspase-1 activation and IL-1ß and IL18 expression. In addition, simultaneous alteration of NLRP3 expression induced changes in intracellular oxidative stress levels after HIBD. These findings indicate that neferine ameliorates neuroinflammation and oxidative stress injury by inhibiting pyroptosis after HIBD. Our study provides valuable information for future studies on neferine with respect to neuroinflammation and pyroptosis.

Myrothins A-F from Endophytic Fungus Myrothecium sp. BS-31 Harbored in Panax notoginseng.

Endophytic fungi play important roles for host's stress tolerance including invasion by pathogenic microbes. Small molecules are common weapons in the microbe-microbe interactions. Panax notoginseng is a widely used traditional Chinese medicinal plant and harbors many endophytes, some exert functions against pathogens. Here, we report six new compounds named myrothins A-F (1-6) produced by Myrothecium sp. BS-31, an endophyte isolated from P. notoginseng, and their antifungal activities against pathogenic fungi causing host root-rot disease. Their structures were elucidated with analysis of spectroscopic data including 1D and 2D NMR, HR-ESI-MS. Myrothins B (2) and E (5) showed the weak activity against Fusarium oxysporum and Phoma herbarum, and myrothins F (6) showed weak activity against F. oxysporum.