Publications by authors named "Yaolan Li"

Article Synopsis
  • Two new compounds, along with four known ones, were discovered in the fruits of Garcinia oblongifolia.
  • The structures of these compounds were determined using various methods, such as mass spectrometry and NMR.
  • Compounds 1 and 2 showed potential as cancer-fighting agents in tests against a specific cell line.
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A new germacrane-type sesquiterpenoid () and a new alkamide (), as well as six known compounds (-) were isolated from the capitula of cv. Fubaiju. The new structures were elucidated by comprehensive spectroscopic analysis and quantum chemical calculations.

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Leading by the antiviral activities against HSV-2 virus, bioactivity-guided the fraction of crude alkaloids from seeds of Peganum harmala led to the isolation of nine structurally novel indole alkaloids, pegaharolines A - I (1-9), and 11 known ones (10-20). Compound 3 was an unusual 6/5/5/5 spirotetracyclic indole-derived alkaloids featuring a classic bicyclic indole unit fused with an additional pyrrolizine ring via a spiral atom (C-3). Compound 4 was determined as a novel indole alkaloid, characterized with a rare hexacyclic 6/5/6/5-6/6 ring system, by a single-crystal X-ray diffraction.

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Unlabelled: Infection with respiratory syncytial virus (RSV) is a major cause of acute lower respiratory tract disease in young children and older people. Despite intensive efforts over the past few decades, no direct-acting small-molecule agents against RSV are available. Most small-molecule candidates targeting the RSV fusion (F) protein pose a considerable risk of inducing drug-resistant mutations.

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Respiratory syncytial virus (RSV) hijacks cholesterol or autophagy pathways to facilitate optimal replication. However, our understanding of the associated molecular mechanisms remains limited. Here, we show that RSV infection blocks cholesterol transport from lysosomes to the endoplasmic reticulum by downregulating the activity of lysosomal acid lipase, activates the SREBP2-LDLR axis, and promotes uptake and accumulation of exogenous cholesterol in lysosomes.

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Influenza therapeutics with new targets and modes of action are urgently needed due to the frequent emergence of mutants resistant to currently available anti-influenza drugs. Here we report the in vitro and in vivo anti-influenza A virus activities of cyperenoic acid, a natural compound, which was isolated from a Chinese medicine Croton crassifolius Geise. Cyperenoic acid could potently suppress H1N1, H3N2 and H9N2 virus replication with IC values ranging from 0.

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Ethnopharmacological Relevance: Traditionally, the roots of Kaempferia galanga has been used to treat high blood pressure, chest pain, headache, toothache, rheumatism, indigestion, cough, inflammation and cancer in Asia. Nevertheless, most of its pharmacological studies were focused on ethanolic extracts and volatile oils. The exact active chemical constituents and their underlying mechanisms are still poorly understood, especially towards its anti-cancer treatment.

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Three novel diterpenoid alkaloids, comprising two C -diterpenoid alkaloids (1 and 2) and one C -diterpenoid alkaloid (3), were isolated from Delphinium ajacis, alongside the six known compounds (4-9). Their structures were elucidated by spectroscopic methods (MS, UV, IR, 1D and 2D NMR) and chemical properties. Simultaneously, the anti-inflammatory properties of all compounds (1-9) was conducted, focusing on nitric oxide (NO) production in LPS-induced BV-2 cells.

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Lysidrhodosides A-I (1-9), nine acylphloroglucinol glucoside derivatives along with three known analogues (10-12) were isolated from the leaves of Lysidice rhodostegia. Their structures and absolute configuration were elucidated by spectroscopic data analysis (NMR, UV, IR, HR-ESI-MS), single-crystal X-ray diffraction, and acid hydrolysis with HPLC analysis. Notably, compounds 7-9 represent the first examples of 3-methylbutyryl phloroglucinol glucoside dimers isolated from this plant.

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Respiratory syncytial virus (RSV) is the leading etiological agent of lower respiratory tract illness. However, efficacious vaccines or antiviral drugs for treating RSV infections are currently not available. Indeed, RSV depends on host cells to provide energy needed to produce progeny virions.

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Fifteen undescribed lindenane-type sesquiterpenoid dimers, designated chloranholides F-T (1-15), together with twenty-five known analogs (16-40), were isolated from the whole plants of Chloranthus holostegius. The isolate structures were elucidated by analysis of spectroscopic data and chemical methods, and their absolute configurations were determined by X-ray crystallography and electronic circular dichroism spectra. In anti-neuroinflammatory assays, all isolates were evaluated by examination of their inhibitory effect on nitric oxide (NO) in LPS-stimulated BV-2 cells, and the results showed that 21-24, 26, 30, 32 and 36 significantly inhibited the production of the inflammatory mediator NO, with IC values ranging from 3.

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Five new sesquiterpenoids (-), elephantmollides A-E, along with four known compounds (-), were isolated from the whole plants of . Their planar structures were elucidated using the spectroscopic methods, including HRESIMS, IR, UV, and NMR (H, C, DEPT, HSQC, HMBC, H-H COSY). The relative configurations of them were partially deduced by the NOESY experiment, and the absolute configurations were assigned by comparing the calculated electronic circular dichroism (ECD) results with the experimental data.

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Non-small cell lung cancer (NSCLC) is a common clinical malignant tumor with limited therapeutic drugs. Leading by cytotoxicity against NSCLC cell lines (A549 and PC9), bioactivity-guided isolation of components from seeds led to the isolation of pegaharoline A (PA). PA was elucidated as a structurally novel aniline derivative, originating from tryptamine with a pyrrole ring cleaved and the degradation of carbon.

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One new fawcettimine-type alkaloid (1), one new miscellaneous-type alkaloid (2), four new lycodine-type alkaloids (3-6), and eight known ones (7-14) were isolated from the whole plants of Huperzia serrata. Their structures and absolute configurations were elucidated based on spectroscopic data, X-ray diffraction, ECD calculation and Mosher's method. Compound 1 was a rare C N -type Lycopodium alkaloid, possessing serratinine skeleton with an amide side chain in C-5.

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Nine undescribed phloroglucinol derivatives (dryatraols A-I) with five different backbones and three known dimeric acylphloroglucinols were isolated from the rhizome of Dryopteris atrata (Wall. Ex Kunze) Ching (Dryopteridaceae). Dryatraol A contains an unprecedented carbon skeleton-a butyrylphloroglucinol and a rulepidanol-type sesquiterpene are linked via a furan ring to form a 6/5/6/6 ring system.

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Phosphoinositide-3 kinase (PI3K) signaling regulates many cellular processes, including cell survival, differentiation, proliferation, cytoskeleton reorganization, and apoptosis. The actin cytoskeleton regulated by PI3K signaling plays an important role in plasma membrane rearrangement. Currently, it is known that respiratory syncytial virus (RSV) infection requires PI3K signaling.

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Human infection with highly pathogenic H5N1 influenza virus causes severe respiratory diseases. Currently, the drugs against H5N1 are limited to virus-targeted inhibitors. However, drug resistance caused by these inhibitors is becoming a serious threat to global public health.

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Eighteen stilbenes (1-18), including six previously undescribed ones (1-6), with diverse modification patterns were isolated from the leaves of edible and medicinal plant Cajanus cajan. Among the new isolates, compounds 1-3 were initially obtained as three racemic mixtures, which were further resolved into three pairs of optically pure enantiomers, respectively, by chiral HPLC. Besides, compounds 8, 10, 11, and 18 were obtained from C.

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Human cytomegalovirus (HCMV) infects a large portion of the human population globally. Several HCMV-derived noncoding RNAs are involved in the regulation of viral gene expression and the virus life cycle. Here, we reported that circRNAs are a new class of HCMV transcripts.

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Inspired by a previously reported biomimetic synthesis study, four new naturally occurring phloroglucinol trimers with unusual 6/5/5/6/6/6-fused hexacyclic ring systems, along with two known analogues ( and ) and two known biogenetically related dimers ( and ), were isolated from . Their structures and absolute configurations were unambiguously elucidated by spectroscopic analysis, X-ray diffraction, and electronic circular dichroism calculation. By mimicking two potentially alternative biosynthetic pathways, the first asymmetric syntheses of and the racemic syntheses of and were achieved in only five to six steps without the need for protecting groups.

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One new alkaloid, 6, 7-dimethoxyisoquinoline--oxide (), one new benzofuran derivative, 3,7-dimethyl-6-acetyl-8-benzofuranol () and one new lignan, salsolains A (), along with seven known compounds (-), were isolated from the whole plant of Pall. Their structures were elucidated by extensive analysis of spectroscopic data (IR, UV, HR-ESI-MS, 1 D and 2 D NMR), and their absolute configurations were determined by the X-ray crystallography and ECD calculation. The activities of compounds - against inflammatory cytokines IL-6 and TNF- levels on LPS-induced RAW 264.

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Circular RNAs (circRNAs) are a newly recognized component of the transcriptome with critical roles in autoimmune diseases and viral pathogenesis. To address the importance of circRNA in RNA viral transcriptome, we systematically identified and characterized circRNAs encoded by the RNA genomes of betacoronaviruses using both bioinformatical and experimental approaches. We predicted 351, 224, and 2764 circRNAs derived from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), SARS-CoV, and Middle East respiratory syndrome coronavirus, respectively.

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Hook.f. (Chinese star anise), a known Chinese traditional spice, is commonly applied in Chinese cuisine and cooking in Southeast Asia.

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Seven new clerodane diterpenoids, crassifolins Q-W (-), along with five known analogues (-), were isolated from the roots of . Their structures were identified by comprehensive spectroscopic analysis (UV, IR, NMR, and HR-ESI-MS), and their absolute configurations were determined by ECD spectra and X-ray crystallography. The activities of compounds - against inflammatory cytokines IL-6 and TNF- levels on LPS-induced RAW 264.

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