Structurally diverse lignans from <i>Solanum lyratum</i>: chemical evidence for their acetylcholinease inhibitory activity

A chemical investigation of Solanum lyratum Thumb. (Solanace) afforded two new lignans (1b and 3) and eleven known lignan analogues (1a, 2a/2b and 4–11). Compounds 1a/1b and 2a/2b were separated as two pairs of enantiomers by chiral high-performance liquid chromatography (HPLC). Their structures were elucidated by detailed spectroscopic and comparative literature data analysis. The absolute configurations of compounds 1a/1b and 2a/2b were determined by comparing the experimental ECD data with the calculated values. All compounds were evaluated for their acetylcholinesterase (AChE) inhibitory activity. Notably, compared to the positive control, compounds 4 and 9 showed obvious AChE inhibition with their IC50 values of 1.30 ± 0.25 and 0.89 ± 0.04 μM, respectively. In addition, the possible interaction between acetylcholinesterase and the active compounds was also investigated by molecular docking.</p

Cytotoxic lignans from the barks of <i>Juglans mandshurica</i>

<p>Phytochemical investigation of the barks of <i>Juglans mandshurica</i> Maxim led to the isolation, purification, and identification of one new lignan named Juglansol A (<b>1</b>), along with nine known compounds (<b>2–10</b>). Their structures were determined by the results of UV, IR, CD, HRESIMS, 1D, and 2D NMR spectroscopic analysis. Compounds <b>1–10</b> were evaluated for their cytotoxicities against A549, HepG2, Hep3B, Bcap-37, and MCF-7 cell lines. The results showed that compound <b>2</b> possessed stronger cytotoxicities against the tested tumor cell lines compared with positive control 5-fluorouracil.</p

Two new sesquineolignans from the seeds of <i>Crataegus pinnatifida</i> and their <i>β</i>-amyloid aggregation inhibitory activitiy

<p>Two new sesquineolignans, hawthornsesquinins K and L (<b>1</b> and <b>2</b>), were isolated from the seeds of <i>Crataegus pinnatifida</i>. Their structures were determined by spectroscopic analyses, including 1D, 2D NMR and HRESIMS data. All isolated compounds were tested for their <i>β</i>-amyloid aggregation inhibitory activity and neuroprotective effects against H₂O₂-induced damage in SH-SY5Y cells. The results indicated that compound <b>1</b> showed prominent inhibition of A<i>β</i>_1–42 aggregation and significant neuroprotective effect on H₂O₂-induced cellular damage in SH-SY5Y cells.</p

Molecular properties, structure and chiral resolution of secondary metabolites from the leaves of <i>Viburnum chingii</i>

A chemical investigation of leaves of Viburnum chingii afforded eleven compounds, including one undescribed lignan (1), a pair of known phenylpropanoid enantiomers (2a/2b), and eight known lignans (3-10). Their structures were elucidated by detailed spectroscopic and comparative literature data analysis. The absolute configurations of compounds 1 was determined by comparing the experimental ECD data with the calculated values. The compounds 2a/2b were separated successfully by a chiral chromatographic column. In addition, the acetylcholinesterase (AChE) inhibitory activities of described compounds were evaluated.</p

Expanded Application of Piper nigrum: Guided Isolation of Alkaloids with Inhibitory Activities of AChE/BuChE and Aβ Aggregation

Piper nigrum is a popular crop that can be used as seasoning or as an additive but its active ingredients also have an effect on the nervous system. Nineteen new amide alkaloids (1a/1b, 2–5, 6a/6b, 7, 8a/8b, 9, 10a/10b, 11a–11b, 12–14) were isolated from P. nigrum, guided by inhibitory activity of AChE and LC–MS/MS based on GNPS. The configurations were determined by extensive spectral analysis, Bulkiness rule, and NMR calculations. The inhibitory activities of AChE/BuChE and Aβ aggregation were tested, and the results showed compounds 2, 7, and 12 had significant inhibitory activities. These components were identified in the crude fraction and their relative quantities were tested, which suggested that compound 2 was the index component in the active site from P. nigrum

<i>ent</i>-Kaurane Diterpenoids with Neuroprotective Properties from Corn Silk (<i>Zea mays</i>)

Thirteen new <i>ent</i>-kaurane diterpenoids, stigmaydenes A–M (<b>1</b>-<b>13</b>), together with two known compounds (<b>14</b>, <b>15</b>), were isolated from the crude extract of corn silk (<i>Zea mays</i>). The structures of the compounds were confirmed by comprehensive spectroscopic analyses. The absolute configuration of compound <b>1</b> was defined by single-crystal X-ray diffraction. The absolute configurations of the compounds were also confirmed by comparison of experimental and calculated specific rotations. The compounds were evaluated for their neuroprotective effects against H₂O₂-induced SH-SY5Y cell injury, and compound <b>8</b> was active at 100 μM, as determined by flow cytometry (annexin V-FITC/PI staining) and Hoechst 33258 staining. The results suggested that compound <b>8</b> could protect neuronal cells from H₂O₂-induced injury by inhibiting apoptosis in SH-SY5Y cells

<i>ent</i>-Kaurane Diterpenoids with Neuroprotective Properties from Corn Silk (<i>Zea mays</i>)

Thirteen new <i>ent</i>-kaurane diterpenoids, stigmaydenes A–M (<b>1</b>-<b>13</b>), together with two known compounds (<b>14</b>, <b>15</b>), were isolated from the crude extract of corn silk (<i>Zea mays</i>). The structures of the compounds were confirmed by comprehensive spectroscopic analyses. The absolute configuration of compound <b>1</b> was defined by single-crystal X-ray diffraction. The absolute configurations of the compounds were also confirmed by comparison of experimental and calculated specific rotations. The compounds were evaluated for their neuroprotective effects against H₂O₂-induced SH-SY5Y cell injury, and compound <b>8</b> was active at 100 μM, as determined by flow cytometry (annexin V-FITC/PI staining) and Hoechst 33258 staining. The results suggested that compound <b>8</b> could protect neuronal cells from H₂O₂-induced injury by inhibiting apoptosis in SH-SY5Y cells

Neuroprotective Effects of 1,2-Diarylpropane Type Phenylpropanoid Enantiomers from Red Raspberry against H₂O₂‑Induced Oxidative Stress in Human Neuroblastoma SH-SY5Y Cells

Red raspberry (<i>Rubus idaeus</i> L.) is an edible fruit-producing species belonging to the Rosaceae family. In our search for the health-promoting constituents from this fruit, four pairs of enantiomeric phenylpropanoids (<b>1a</b>/<b>1b</b>–<b>4a</b>/<b>4b</b>), including three new compounds (<b>1a</b> and <b>2a</b>/<b>2b</b>), were isolated from red raspberry. Their structures were elucidated by a combination of the extensive NMR spectroscopic data analyses, high-resolution electrospray ionization mass spectrometry and comparison between the experimental measurements of electronic circular dichroism (ECD) and calculated ECD spectra by time-dependent density functional theory (TDDFT). In addition, their neuroprotective effects against H₂O₂-induced oxidative stress in human neuroblastoma SH-SY5Y cells were investigated, and the results showed enantioselectivity, in which that <b>3a</b> exhibited noticeable neuroprotective activity, while its enatiomer <b>3b</b> exhibited no obvious protective effect. Further study demonstrated that <b>3a</b> could selectively inhibit the apoptosis induction and reactive oxygen species (ROS) accumulation by enhancing the activity of catalase (CAT) in H₂O₂-treated human neuroblastoma SH-SY5Y cells. These findings shed much light on a better understanding of the neuroprotective effects of these enantiomers and provide new insights into developing better treatment of neurodegenerative diseases in the future

A new coumarin from <i>Juglans mandshurica</i> Maxim induce apoptosis in hepatocarcinoma cells

<p>In this study, a new coumarin, juglansoside C (<b>1</b>) was isolated from the bark of <i>Juglans mandshurica</i>. Its chemical structure was identified by comprehensive spectroscopic analyses. The <i>in vitro</i> cytotoxicity assay showed that <b>1</b> exhibited moderate cytotoxicity against human hepatocellular carcinoma Hep3B cells with an IC₅₀ value of 70.9 μM. Furthermore, Annexin V-FITC/PI staining assay indicated that <b>1</b> markedly induced apoptosis in Hep3B cells.</p

Antioxidant and Anti-inflammatory Active Dihydrobenzofuran Neolignans from the Seeds of Prunus tomentosa

Prunus tomentosa seeds were researched for antioxidant and anti-inflammatory constituents. By activity-guided fractionation of <i>P. tomentosa</i> seed extract, six new dihydrobenzofuran neolignans, prunustosanans AI-IV (<b>1</b>–<b>4</b>) and prunustosanansides AI and AII (<b>5</b> and <b>6</b>), together with 10 known compounds (<b>7</b>–<b>16</b>) were isolated from bioactive fraction. The structures were determined by spectroscopic analyses, especially NMR, HRESIMS, and CD spectra. The antioxidant activity was greatest for <b>5</b>, <b>10</b>, and <b>12</b> against DPPH radical and for <b>8</b>, <b>9</b>, and <b>13</b> against ABTS radical. Moreover, compounds <b>7</b> and <b>11</b> exhibited much stronger inhibitory activity on nitric oxide (NO) production in murine microglia BV-2 compared with positive control minocycline (IC₅₀ = 19.7 ± 1.5 μM). The results show that <i>P. tomentosa</i> seeds can be regarded as a potential source of antioxidants and inflammation inhibitors