The persistent mutation of the novel coronavirus presents a continual threat of infections and associated illnesses. While considerable research efforts have concentrated on the functional proteins of SARS-CoV-2 in the development of anti-COVID-19 therapeutics, the structural proteins, particularly the N protein, have received comparatively less attention. This study focuses on the N protein, a critical structural component of the virus, and employs advanced deep learning models, including EMPIRE and DeepFrag, to optimize the structures of phenanthridine-based compounds.
View Article and Find Full Text PDFDaphmacrimines A-K (1-11) were isolated from the leaves and stems of Daphniphyllum macropodum Miq. Their structures and stereochemistries were determined by extensive techniques, including HRESIMS, NMR, ECD, IR, and single-crystal X-ray crystallography. Daphmacrimines A-D (1-4) are unprecedented Daphniphyllum alkaloids with a 2-oxazolidinone ring.
View Article and Find Full Text PDFFive new toosendanin limonoids with highly oxidative furan ring walsurobustones A-D (1-4), and one new furan ring degraded limonoid walsurobustone E (5) together with one known compound toonapubesic acid B (6) were isolated from the leaves of Walsura robusta. Their structures were elucidated by NMR and MS data. Especially, the absolute configuration of toonapubesic acid B (6) was confirmed by X-ray diffraction study.
View Article and Find Full Text PDFHumans have been suffering from vitiligo for a long time. Target vitiligo drugs have yet been approved. Activation of Wnt/β-catenin signalling has potential in the therapeutic use of vitiligo, so exploring new drugs that specifically directly activate Wnt is worthwhile to obtain new anti-vitiligo agents.
View Article and Find Full Text PDFThe COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unprecedented in human history. As a major structural protein, nucleocapsid protein (NPro) is critical to the replication of SARS-CoV-2. In this work, 17 NPro-targeting phenanthridine derivatives were rationally designed and synthesized, based on the crystal structure of NPro.
View Article and Find Full Text PDFTwo new cycloartane triterpenoids, (24 )-cycloartane-3,24,25,30-tetrol () and (24 )-24,25,30-trihydroxy-9,19-cycloartane-3-one (), along with three known compounds () were isolated from leaves and twigs of . The new compounds were elucidated based on comprehensive spectroscopic analysis, including 1 D, 2 D NMR and HREIMS. The in vitro cytotoxic activities evaluation of five human cancer cell lines revealed that compound exhibited cytotoxic activity on all of tested human cancer cell lines, while compound only had specific activity on SMMC-7721 cell line.
View Article and Find Full Text PDFPorcine epidemic diarrhea virus (PEDV) has become increasingly problematic around the world, not only for its hazards to livestock but also due to the possibility that it is a zoonotic disease. Although vaccine therapy has made some progress toward PEDV control, additional effective therapeutic strategies against PEDV are needed, such as the development of chemotherapeutic agents. The aim of this work was to identify novel anti-PEDV agents by designing and synthesizing a series of phenanthridine derivatives.
View Article and Find Full Text PDFAphananoid A, a limonoid which features a rare C appendage and new 5/6/5 fused-ring framework, was obtained from . The planar structure as well as the absolute configuration was identified based on extensive spectroscopic analysis and electronic circular dichroism calculations. The biogenetic pathway of aphananoid A was also speculated, which arises from the triterpene by the 3,4--7,8--6,8 -7,30- key pattern.
View Article and Find Full Text PDFSix new diterpenes Euphonoids A-F including one ingenol (1), three lathyrane (2-5), one ent-abietane (6) and fifteen known derivatives (7-21) were isolated from the aerial parts of Euphorbia antiquorum L. Their structures were elucidated by physical data analysis. Compounds 1, 12, and 16 improve the melanogenesis in B16 cells in vitro.
View Article and Find Full Text PDFTwo new sesquiterpenoids were isolated from Stellera chamaejasme L., known as the traditional Chinese herb 'Rui Xiang Lang Du'. The compounds were elucidated as stelleraguaianone B (1) and C (2) by comprehensive spectroscopic analysis, including 1D and 2D NMR as well as HRESIMS, and by comparing their NMR data with known compounds.
View Article and Find Full Text PDFTwo new lignans (-), along with five known compounds (-) with different structures were isolated from leaves and twigs of Croizat. The new lignans were elucidated as (7'R,8'S)-3,3',5'-trimethoxy-4,4'-dihydroxy-7-en-7',9- epoxy-8,8'-lignan () and (7'R,8'S)-3,3'-dimethoxy-4,4'-dihydroxy-7-en-7',9-epoxy-8, 8'-lignan () by comprehensive spectroscopic analysis including 1D and 2D NMR as well as HREIMS and comparing their NMR data with known compounds in the literature. Among these isolated compounds, compound , , , and were tested for anti- inflammatory effects by inhibiting NO production in lipopolysaccharide (LPS)-stimulated RAW 264.
View Article and Find Full Text PDFNat Prod Bioprospect
August 2018
Xiaojiang Hao, who obtained Master Degree from Kunming Institute of Botany (KIB), Chinese Academy of Sciences (CAS) in 1985, and Doctor in Pharmacy degree in Pharmacy from Institute for Chemical Research, Kyoto University, in 1990, was born in Chongqing in July, 1951. In 1991, he returned to KIB, CAS, as an Associate professor and served as the chair of the Department of Phytochemistry. In 1994, he was promoted to a full professor at the current institute.
View Article and Find Full Text PDFTwo new 6-norpolycyclic polyprenylated acylphloroglucinols (PPAPs), hypermonins A (1) and B (2), featuring an undescribed decahydroindeno[1,7-bc]furan ring system, were isolated from the leaves and twigs of Hypericum monogynum. These compounds are a pair of epimers with opposite configurations at the C-5 position. Their structures, including their absolute configurations, were determined by extensive spectroscopic analysis and electronic circular dichroism (ECD) calculations.
View Article and Find Full Text PDFFifteen known amaryllidaceae alkaloids were isolated from the bulbs of Lycoris radiata. Some of the compounds and lycoricidine derivatives had been screened for the activities against tobacco mosaic virus (TMV) by the conventional half-leaf method. Lycoricidine derivatives were also carried out the assay of effect on systemic infection of TMV by western-blot and RT-PCR analysis.
View Article and Find Full Text PDFFour new indole alkaloids, melodinusines A-D (1, 2, 6, and 7), along with 26 known indole alkaloids, were isolated from Melodinus tenuicaudatus and Melodinus khasianus (Melodinus genus). Among them, 1 and 2 are aspidospermine-aspidospermine-type bisindole alkaloids while 7 is a novel melodinus-type alkaloid. Their structures were established on the basis of comprehensive spectroscopic data analysis and the structure of 7 was further confirmed by single-crystal X-ray diffraction analysis.
View Article and Find Full Text PDFRare ent-abietane-rosane diterpenoid heterodimers, Bisebracteolasins A and B (1 and 2, respectively), were isolated from the roots of Euphorbia ebracteolata Hayata. Their structures and absolute configurations were elucidated from spectroscopic data and X-ray diffraction analysis. Compounds 1 and 2 exhibited moderate cytotoxic effects against five cancer cell lines.
View Article and Find Full Text PDF(+)-Perforison A and (-)-perforison A, a new pair of chromone enantiomers, along with four known compounds, were isolated from the leaves and stems of Harrisonia perforata. Their structures and absolute configurations were determined on the basis of extensive analysis of spectroscopic data and electronic circular dichroism (ECD) calculations. The cytotoxic activities in vitro of these compounds were evaluated, but none showed significant activity.
View Article and Find Full Text PDFFour new Myrioneuron alkaloids, mysumamides A-D (1-4), along with three known ones were isolated from the twigs and leaves of Myrioneuron effusum. All of these alkaloids possessed the tetracyclic skeleton and contained the decahydroquinoline (cis-DHQ) moiety. Their structures and relative configurations were elucidated on the basis of spectroscopic methods, especially 2D NMR techniques.
View Article and Find Full Text PDFLycorine is a benzylphenethylamine-type alkaloid member of the Amaryllidaceae family. A lycorine derivative, HLY78, was previously identified as a new Wnt/β-catenin signaling pathway agonist that targets the DAX domain of axin. Herein, the structural optimization of HLY78 and analyses of the structure-activity relationships of lycorine-derived phenanthridine derivatives as agonists of the Wnt/β-catenin signaling pathway are presented.
View Article and Find Full Text PDFThree new Myrioneuron alkaloids, myrifamines A-C (1-3), with unique skeletons were isolated from Myrioneuron faberi. The absolute configuration of 1 was confirmed by single-crystal X-ray diffraction analysis, and the stereochemistry of the other two alkaloids was determined using a combination of ROESY experiments and calculated and experimental electronic circular dichroism spectra. Myrifamine C (3) is the first example of a symmetric dimer among the Myrioneuron alkaloids.
View Article and Find Full Text PDFFourteen new limonoids, munronins A-N (1-14), and eight known limonoids (15-22) were isolated from the whole plants of Munronia henryi. The structures of the new compounds were elucidated by 2D NMR spectroscopy and mass spectrometry, and the structure of 8 was confirmed by single-crystal X-ray diffraction analysis. Compound 1 represents the first limonoid found with a novel 7-oxabicyclo[2.
View Article and Find Full Text PDFTwo new compounds, maniesculentins A (1) and B (6), together with four known ones were isolated from the stems of Manihot esculenta Crantz. The structures of the new compounds were elucidated by extensive spectroscopic methods including NMR spectroscopy and mass spectrometry. The two new compounds (1, 6) were assayed for antibacterial activity against four tested bacteria lines.
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