A new terpestacin-type sesterterpenoid with tricyclic 3/15/5 scaffold from an endophytic fungus sp. J019.

ABSTACTChemical investigation of an endophytic fungus, sp. J019, isolated from the plant species R. Br.

Highly Enantioselective Construction of Chiral Eight-Membered Cyclic Ethers through Tandem Cyclization of Ynones and Dicarbonyl Compounds.

The enantioselective synthesis of eight-membered cyclic ether has always been a challenge in organic synthesis. Herein, we reported a highly enantioselective tandem cyclization reaction of alkyne ketone and dioxypyridines mediated by chiral bifunctional catalysts. This reaction generates two adjacent stereocenters using an atomeconomic manner, providing a simple and effective method for the one-step synthesis of highly enantioselective eight-membered cyclic ethers.

The potential of marine natural Products: Recent Advances in the discovery of Anti-Tuberculosis agents.

Tuberculosis (TB) is an infectious airborne disease caused by Mycobacterium tuberculosis. Since the 1990 s, many countries have made significant progress in reducing the incidence of TB and associated mortality by improving health services and strengthening surveillance systems. Nevertheless, due to the emergence of multidrug-resistant TB (MDR-TB), alongside extensively drug-resistant TB (XDR-TB) and TB-HIV co-infection, TB remains one of the lead causes of death arising from infectious disease worldwide, especially in developing countries and disadvantaged populations.

New Pyranone Derivatives and Sesquiterpenoid Isolated from the Endophytic Fungus sp. Z184.

The fungus sp. Z184, harvested from the leaves of (L.) Á.

Enantioselective synthesis of spirooxindole-pyran derivatives a remote inverse-electron-demand Diels-Alder reaction of β,γ-unsaturated amides.

Novel construction methods for obtaining 3,4'-pyran spirooxindole heterocyclic skeletons have always been the focus of attention. Herein, we report a highly enantioselective inverse-electron-demand oxa-Diels-Alder cycloaddition reaction of a β,γ-unsaturated pyrazole amide and a -diphenyl isatin-derived oxodiene using a bifunctional catalyst. In addition, large-scale experiments confirmed the reliability of the reaction.

Identification of indocyanine green as a STT3B inhibitor against mushroom α-amanitin cytotoxicity.

The "death cap", Amanita phalloides, is the world's most poisonous mushroom, responsible for 90% of mushroom-related fatalities. The most fatal component of the death cap is α-amanitin. Despite its lethal effect, the exact mechanisms of how α-amanitin poisons humans remain unclear, leading to no specific antidote available for treatment.

-Pregnane Glycosides from Australian Caustic Vine ( subsp. ).

subsp. , more commonly known as caustic vine, is a leafless succulent that grows in the northern arid zone of Australia. Toxicity toward livestock has been reported for this species, along with use in traditional medicine and its potential anticancer activity.

Anti-Neuroinflammatory Activity of New Naturally Occurring Benzylated Hydroxyacetophenone Analogs from the Endophytic Fungus Alternaria sp. J030.

Chemical studies on the culture broth of the endophytic fungus Alternaria sp. J030 led to the identification of three benzylated hydroxyacetophenone derivatives, bauvaroalterins A-C (1-3), and 34 structurally diverse metabolites (4-37). The new structures were elucidated by extensive spectroscopic analyses including UV, IR, 1D and 2D NMR, HR-ESI-MS, and further confirmed using single crystal X-ray diffraction.

and Analysis of Phytochemicals From as Dual Functional Cholinesterase Inhibitors for the Treatment of Alzheimer's Disease.

Current studies have found that butyrylcholinesterase (BuChE) replaces the biological function of acetylcholinesterase (AChE) in the late stage of Alzheimer's disease. Species in the genus of Fallopia, rich in polyphenols with diverse chemical structures and significant biological activities, are considered as an important resource for screening natural products to against AD. In this study, thirty-four compounds (1-34) were isolated from Fallopia dentatoalata (Fr.

Glycosylated coumarins, flavonoids, lignans and phenylpropanoids from and their biological activities.

Champ. ex Benth., a traditional herbal medicine collected at the Lingnan region of China, was chemically investigated.

Acorenone C: A New Spiro-Sesquiterpene from a Mangrove-Associated Fungus, sp. J003.

Mangrove-derived endophytes are rich in bioactive secondary metabolites with a variety of biological activities. Recently, a fungus sp. J003 was first isolated by our research group from mangrove species Buch.

Regioisomers Salviprolin A and B, Unprecedented Rosmarinic Acid Conjugated Dinorditerpenoids from Maxim.

Maxim is a perennial plant from the genus (family Lamiaceae). The roots of were long used as a traditional herb to treat blood circulation related illnesses in China. As part of our continuing interest in polycyclic natural products from medicinal plants, two unprecedented adducts comprised of a -diterpenoid and a 9'--rosmarinic acid derivative, linked by a 1,4-benzodioxane motif ( and ), were isolated from the roots of .

CK2 Inhibits TIMELESS Nuclear Export and Modulates CLOCK Transcriptional Activity to Regulate Circadian Rhythms.

Circadian clocks orchestrate daily rhythms in organismal physiology and behavior to promote optimal performance and fitness. In Drosophila, key pacemaker proteins PERIOD (PER) and TIMELESS (TIM) are progressively phosphorylated to perform phase-specific functions. Whereas PER phosphorylation has been extensively studied, systematic analysis of site-specific TIM phosphorylation is lacking.

EYES ABSENT and TIMELESS integrate photoperiodic and temperature cues to regulate seasonal physiology in .

Organisms possess photoperiodic timing mechanisms to detect variations in day length and temperature as the seasons progress. The nature of the molecular mechanisms interpreting and signaling these environmental changes to elicit downstream neuroendocrine and physiological responses are just starting to emerge. Here, we demonstrate that, in , EYES ABSENT (EYA) acts as a seasonal sensor by interpreting photoperiodic and temperature changes to trigger appropriate physiological responses.

A GAN-based image synthesis method for skin lesion classification.

Background And Objective: There are many types of skin cancer, and melanoma is the most lethal one. Dermoscopy is an important imaging technique to screen melanoma and other skin lesions. However, Skin lesion classification based on computer-aided diagnostic techniques is a challenging task owing to the scarcity of labeled data and class-imbalanced dataset.

SUR-8 interacts with PP1-87B to stabilize PERIOD and regulate circadian rhythms in Drosophila.

Circadian rhythms are generated by endogenous pacemakers that rely on transcriptional-translational feedback mechanisms conserved among species. In Drosophila, the stability of a key pacemaker protein PERIOD (PER) is tightly controlled by changes in phosphorylation status. A number of molecular players have been implicated in PER destabilization by promoting PER progressive phosphorylation.

Splice variants of DOMINO control Drosophila circadian behavior and pacemaker neuron maintenance.

Circadian clocks control daily rhythms in behavior and physiology. In Drosophila, the small ventral lateral neurons (sLNvs) expressing PIGMENT DISPERSING FACTOR (PDF) are the master pacemaker neurons generating locomotor rhythms. Despite the importance of sLNvs and PDF in circadian behavior, little is known about factors that control sLNvs maintenance and PDF accumulation.

Basimarols A, B, and C, Highly Oxygenated Pimarane Diterpenoids from .

The highly oxygenated pimarane diterpenoids basimarols A, B, and C (-) were isolated from the plant species , which was collected within the Australian arid zone. Structure elucidation was performed using a suite of spectroscopic techniques, including X-ray crystallography. Anticancer and anti-DENV activity of - was explored, but only limited activity was observed.

Asperpyridone A: An Unusual Pyridone Alkaloid Exerts Hypoglycemic Activity through the Insulin Signaling Pathway.

A pyridone alkaloid, asperpyridone A (), which possesses an unusual pyrano[3,2-]pyridine scaffold, was isolated from solid cultures of the endophytic fungus sp. TJ23. Its structure, including its absolute configuration, was determined using a combination of nuclear magnetic resonance, high-resolution electrospray ionization mass spectrometry, quantum chemical calculations (electronic circular dichroism), and X-ray crystallography.

Przewalcyrones A-F, epoxychromene-containing polycyclic polyprenylated acylphloroglucinols with immunosuppressive activity from Hypericum przewalskii Maxim.

Chemical investigation of the extracts of the aerial parts of Hypericum przewalskii Maxim. resulted in the isolation and identification of six new epoxychromene-containing polycyclic polyprenylated acylphloroglucinols (PPAPs), named przewalcyrones A-F (1-6), and one known analogue (7). All of the structures were determined based on extensive spectroscopic analyses, X-ray crystallographic analysis, modified Mosher's method, [Rh(OCOCF)]-induced ECD, and electronic circular dichroism (ECD) comparison.

HPLC-DAD-Directed Isolation of Linearly Fused Prenylated Indole Alkaloids from a Soil-Derived .

An HPLC-DAD-directed chemical investigation of the soil-derived fungus QC812 resulted in the isolation and identification of eight new linearly fused prenylated indole alkaloids, asperversiamides I-P (-), along with a congener, asperversiamide H (). Their structures and absolute configurations were determined by spectroscopic analysis including HRESIMS and 1D and 2D NMR, electronic circular dichroism analysis, and single-crystal X-ray diffraction. Asperversiamide I (), the first diketopiperazine derived from d-proline and l-tryptophan, possesses an unprecedented C-11-spiro-fused 6/6/5/5/6/5 hexacyclic ring system.

Hyperforatins L-U: Prenylated acylphloroglucinols with a terminal double bond from Hypericum perforatum L. (St John's Wort).

Hyperforatins L-U, ten undescribed polycyclic polyprenylated acylphloroglucinols (PPAPs) bearing a terminal double bond, together with a known compound hypericumoxide J, were isolated from the aerial parts of Hypericum perforatum L. Their structures were elucidated by spectroscopic methods, including HRESIMS, IR, UV, and NMR (H, C, DEPT, HSQC, HMBC, H-H COSY, and NOESY experiments). Their absolute configurations were determined by comprehensive analyses of their experimental ECD spectra in conjunction with a modified Mosher's method.

Anti-Inflammatory Activities of Leaf Oil from and .

The study determined the chemical constituents and anti-inflammatory effects of leaf oil from (CS-LO) that has been used in folk medicine to treat various symptoms including inflammation. The anti-inflammatory effects of the oil were evaluated by LPS-stimulated RAW264.7 cells and the Carr-induced hind mouse paw edema model, respectively.

Loss of in Circadian Cells Decreases the Amplitude of the Circadian Locomotor Rhythm in .

The circadian system, which has a period of about 24 h, is import for organismal health and fitness. The molecular circadian clock consists of feedback loops involving both transcription and translation, and proper function of the circadian system also requires communication among intracellular organelles. As important hubs for signaling in the cell, mitochondria integrate a variety of signals.