查看更多>>摘要：? 2022 Elsevier B.V.Isogeopyxins A–C (1–3), three new diterpenoids with ent-kaurane, ent-pimarane, and ent-abietane scaffolds, respectively, along with six known ent-kauranoids, were isolated from the fermentation culture of Geopyxis sp. XY93 inhabiting the leaves of Isodon parvifolia. Their structures were elucidated by interpretation of spectroscopic data, and single crystal X-ray diffraction. It marks the first time that ent-kauranoids, characteristic metabolites of Isodon species, have been isolated from an associated endophytic fungus.
查看更多>>摘要：? 2022Four undescribed sesquiterpenes (1–4) and 20 known sesquiterpenes (5–24) were obtained from the fruits of Litsea lancilimba Merr. by Small Molecule Accurate Recognition Technology (SMART). The gross structures and the relative configurations of the new compounds were deduced by spectroscopic data analysis. The absolute configurations were defined by comparison of their experimental and calculated electronic circular dichroism (ECD) spectra data. All compounds were screened for their neuroprotective effects against H2O2-induced SH-SY5Y cells injury. Compounds 2, 3, 7, 8 and 13 exhibited comparable neuroprotective activity to the positive trolox at 50 μM.
查看更多>>摘要：? 2022 Elsevier B.V.Inflammation is a critical defense mechanism for body which is crucial for wound healing. However, when it spirals out of control and becomes chronic, it possesses a risk for diseases such as metabolic disorders or cancer. Scutellaria L. species are known with their potent anti-inflammatory effects. We aim to investigate the potential anti-inflammatory effects of Scutellaria brevibracteata Stapf and its active principles with underlying mechanisms using both in vitro and in vivo methods. Aqueous extract of S. brevibracteata (SB) was chromatographed on several columns to get 6 main fractions and 2 pure compounds. The levels of IL-6, NO, and TNF-α were measured in LPS-induced RAW 264.7 cells. In vivo carrageenan-induced paw edema test and immunoblotting in these paws were performed. SB was significantly reduced the inflammation in LPS-induced RAW cells via IL-6 and TNF-α cytokines at 200 μg/mL (P < 0.001) and paw edema via COX-2 and iNOS (P < 0.001). 3-O-methyl kaempferol, isolated from SB, reduced the production of NO, IL-6 and TNF-α in LPS-stimulated macrophages at 50 μM (P < 0.001); it significantly diminished inflammation-induced edema and COX-2, iNOS, and NF-κB protein levels were reduced compared to control group (P < 0.001). It was noticed that the methoxylation of C3 position has no effect on the anti-inflammatory mechanism of action comparing with kaempferol. In vivo studies indicated 3-O-methyl kaempferol was as effective as indomethacin. Considering the side effects caused by indomethacin, this compound can be evaluated as a novel drug candidate in inflammatory diseases with fewer side effects.
查看更多>>摘要：? 2022Pharmacophore-probe reaction guided purification strategy can reduce the workload of natural product chemistry and raise the probability of obtaining undescribed and high-bioactive target compounds. In this study, a probe of N-acetyl cysteine (NAC) was used to confirm the pharmacophore of Tubocapsicum anomalum (Franch. et Sav.) Makino. Furthermore, a thiol probe named 4-bromothiophenol (BTP) guided the discovery of three undescribed (1–3) and nine known (4–12) electrophilic withanolides (EWs) featured potential anti-triple negative breast cancer (TNBC) pharmacophore. Notably, co-incubation with BTP made the single crystals of EW conjugates much more accessible, which facilitated the absolute configuration determination of EWs. Electrophilic natural products with the potential of thio-alkylation modification and covalent inhibition key proteins in tumor cell signal transduction pathways may display significant antitumor activity. The MTT results indicated that most EWs showed anti-TNBC activity and were expected to develop anti-TNBC candidate drugs with high selectivity and novel mechanism.
查看更多>>摘要：? 2022 Elsevier B.V.Twelve dihydro-β-agarofuran-type sesquiterpenoids, including five new ones (1–5), were purified from the seeds of Celastrus virens (Wang et Tang) C. Y. Chent et T. C. Kao. Their chemical structures were characterized via comprehensive spectroscopic analysis, single-crystal X-ray diffraction analysis, and computational prediction of ECD, as well as comparison of observed and reported NMR spectral data. Among the isolates, nine abundant dihydro-β-agarofuran-type sesquiterpenoids were evaluated for their lifespan-extending activity using the nematode Caenorhabditis elegans model. As a result, compounds 1, 2, 5, 6, 8, and 9 (50 μM) significantly extended the mean survival time of C. elegans, respectively, compared with the blank control group (p < 0.05). Further Quantitative RT-PCR showed that the prolonging of lifespan mediated by compounds 1, 6, 8, and 9 were dependent on the transcription factors skn-1 and hsf-1.
查看更多>>摘要：? 2022 Elsevier B.V.This is the first phytochemical investigation of Schisandra tomentella A. C. Smith. 11 lignans and 8 sesquiterpenoids, were isolated from the stems of S. tomentella, including two undescribed lignans, tomentaschinins A-B (1–2), and two new sesquiterpenoids, tomentaschinnes A-B (3–4). Their structures were elucidated based on the interpretation of their spectroscopic data. Cytotoxicity and MDR reversal effect of these compounds were screened on multidrug resistance cancer cell line MCF-7/ADR, and results showed gomisin M2 (7) could promote the efficacy of adriamycin against MCF-7/ADR.
查看更多>>摘要：? 2022 Elsevier B.V.Proanthocyanidins (PACs) have various bioactivities, such as being anti-bacterial, anti-cancer, and anti-oxidant. Consequently, they have been vigorously studied for the development of new natural bioactive compounds. Recently, PAC was isolated from leaves and pseudostems of the medicinal plant Alpinia zerumbet (Pers.) B.L. Burtt and R.M. Smith, and it had shown in vitro antiviral activity against influenza A H1N1 viruses (IAVs). The 50% endpoint dilution method indicated that 0.1 mg/mL A. zerumbet-derived PAC (AzPAC) reduced the titer of IAVs by >3 logs. The antiviral activity of AzPAC means that it can interact directly with viral particles since the antiviral activity test was done by coincubation of PAC with and IAVs before viral infection. However, few studies have investigated the preventive mechanism utilized by AzPAC on influenza virus replication. In this study, the composition of AzPAC and the affinity between AzPAC and IAVs was investigated in detail. We found that AzPAC was composed of an epicatechin, which was linked by inter-flavan bonds between the C4 and C8 positions (B2-type) and the C4 and C6 positions (B5-type) in the terminal units. A quenching assay indicated that AzPAC interacted with IAV membrane proteins, hemagglutinin and neuraminidase. Additionally, circular dichroism analysis indicated that AzPAC affected the change in the secondary structure rate of the viral membrane proteins. AzPAC was able to impair the infective process of IAVs via direct interaction with their viral membrane proteins. These results indicate that A. zerumbet is a bioresource for the development of preventive drugs against IAV infection.
查看更多>>摘要：? 2022 The Author(s)The CH2Cl2/MeOH (1:1) extract of the stems of Tephrosia uniflora yielded the new β-hydroxydihydrochalcone (S)-elatadihydrochalcone-2'-methyl ether (1) along with the three known compounds elongatin (2), (S)-elatadihydrochalcone (3), and tephrosin (4). The structures were elucidated by NMR spectroscopic and mass spectrometric data analyses. Elongatin (2) showed moderate antibacterial activity (EC50 of 25.3 μM and EC90 of 32.8 μM) against the Gram-positive bacterium Bacilus subtilis, and comparable toxicity against the MCF-7 human breast cancer cell line (EC50 of 41.3 μM). Based on the comparison of literature and predicted NMR data with that obtained experimentally, we propose the revision of the structures of three β-hydroxydihydrochalcones to flavanones.
查看更多>>摘要：? 2022 Elsevier B.V.Five new cholestane glycosides, named parisfargosides A–E (1–5), were isolated from the rhizomes of Paris fargesii. Their structures were elucidated on the basis of UV, HR-ESI-MS, 1D and 2D NMR data as well as chemical methods. The structures of all compounds contained α, β-unsaturated ketone unit. Compounds 3–5 possessed a 16,23-cyclocholest skeleton with 6/6/6/5/5 condensed ring, and the absolute configurations of C-16 and C-23 were confirmed according to ROESY spectra with pyridine?d5 and DMSO?d6 as solvents. In addition, the platelet aggregation activity and cytotoxic activity against five human cancer cell lines (HL-60, A549, SMMC-7721, MDA-MB-231, and SW480) of compounds 1–5 were evaluated.
查看更多>>摘要：? 2022A pair of enantiomers with a rearranged dimeric phenylethanol skeleton, namely (±)-disyringol A (1a and 1b), were isolated from the stem barks of Syringa pinnatifolia. The structures were established using IR, UV, MS, and NMR data, and their absolute configurations were resolved by experimental and calculated ECD data analysis. Their biosynthetic pathway was speculated on the basis of a phenylethanoid precursor and was proved by a total synthesis. Compounds 1a and 1b showed the inhibition against NO production in LPS-induced RAW264.7 cells with their IC50 values of 27.28 and 24.64 μM, respectively, however no protective effect was observed against the hypoxia-induced injuries to H9c2 cells.
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