Food Byproducts as a New and Cheap Source of Bioactive Compounds: Lignans with Antioxidant and Anti-inflammatory Properties from Crataegus pinnatifida Seeds

During the process of manufacturing hawthorn (Crataegus pinnatifida) juice and jam, a significant quantity of byproducts (leaves, seeds) is generated. The antioxidant and anti-inflammatory bioassay-guided fractionation of the extract of hawthorn seeds has led to the isolation of eight new lignans, hawthornnins A–H (<b>1</b>–<b>8</b>), and seven known analogues (<b>9</b>–<b>15</b>). Their structures were elucidated by spectroscopic techniques, including 1D and 2D NMR and CD spectra. The radical-scavenging effects of all isolated compounds were investigated. <b>1</b>–<b>6</b> and <b>8</b> showed moderate activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH), whereas <b>1</b>–<b>6</b> and <b>14</b> displayed good 2,2′-azinobis­(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical-scavenging activities that were even more potent than that of trolox. In addition, all isolates were evaluated for their anti-inflammatory activities by detecting the nitric oxide (NO) and tumor necrosis factor α (TNF-α) production by the LPS-induced murine macrophage cell line RAW264.7, and compounds <b>1</b>–<b>7</b>, <b>13</b>, and <b>14</b> exhibited potent inhibition of NO and TNF-α production. The structure–activity relationships of isolated lignans were also examined, and the results obtained show that <i>C. pinnatifida</i> seeds can be regarded as a potential new and cheap source of antioxidants and inflammation inhibitors

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

Antioxidant and cytotoxic lignans from the roots of <i>Bupleurum chinense</i>

<p>In the search for biologically active compounds from the roots of <i>Bupleurum chinense</i> D C., phytochemical investigation of its ethanol extract led to the isolation and identification of a new 8-<i>O</i>-4′ neolignan glucoside, saikolignanoside A (<b>1</b>), along with eight known lignans (<b>2–9</b>). Their structures were determined on the basis of IR, UV, HRESIMS, and NMR spectroscopic analyses. The antioxidant and cytotoxic effects of isolated compounds were evaluated <i>in vitro</i>. The isolated compounds (IC₅₀ > 200 μM) did not display 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. Whereas compounds <b>1–2</b>, <b>5</b>, <b>7,</b> and <b>9</b> exhibited potent 2, 2′-azinobis(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) free radical scavenging properties with IC₅₀ values ranging from 8.34 to 15.24 μM, while compounds <b>3–4</b>, <b>6</b>, <b>8</b> showed moderate properties. In addition, all compounds were evaluated for cytotoxicities against A549, HepG2, U251, Bcap-37, and MCF-7 cell lines. Compounds <b>5</b> and <b>9</b> (IC₅₀< 51.62 μM) possessed stronger cytotoxic activities against all the tested tumor cell lines, compared with the positive control 5-Fluorouracil.</p