α‑Glucosidase Inhibitory Hydrolyzable Tannins from <i>Eugenia jambolana</i> Seeds

Three new hydrolyzable tannins including two gallotannins, jamutannins A (<b>1</b>) and B (<b>2</b>), and an ellagitannin, iso-oenothein C (<b>3</b>), along with eight known phenolic compounds were isolated from the seeds of <i>Eugenia jambolana</i> fruit. The structures were elucidated on the basis of spectroscopic data analysis. All compounds isolated were evaluated for α-glucosidase inhibitory effects compared to the clinical drug acarbose

Anti-Ferroptotic Effect of Cannabidiol in Human Skin Keratinocytes Characterized by Data-Independent Acquisition-Based Proteomics

Skin cells are susceptible to oxidative stress and various types of cell death, including an iron-dependent form known as ferroptosis. Cannabidiol (CBD) can protect skin cells against oxidative stress, but whether this is attributed to the inhibition of ferroptosis is unknown. Herein, we evaluated the anti-ferroptotic effect of CBD in human keratinocytes using biochemical assays (radical scavenging and iron chelating) and cell-based models (for lipid peroxidation and intracellular iron). CBD’s anti-ferroptotic effect was further characterized by proteomic analysis. This study identifies anti-ferroptosis as a mechanism of CBD’s skin protective effects

Skrip_et_al-JEB-zebra_finch_data

This file contains data used to perform statistical analyses: circulating oxidative damage data from adult zebra finches for repeated measures ANOVA; circulating antioxidant capacity data from zebra finches for repeated measures ANOVA; liver antioxidant enzyme data from adult zebra finches for ANOVA; yolk antioxidant and egg size data from zebra finch eggs for mixed general linear models

Isolation, Identification, and Biological Evaluation of Phenolic Compounds from a Traditional North American Confectionery, Maple Sugar

Maple sap, collected from the sugar maple (Acer saccharum) tree, is boiled to produce the popular plant-derived sweetener, maple syrup, which can then be further evaporated to yield a traditional North American confectionery, maple sugar. Although maple sap and maple syrup have been previously studied, the phytochemical constituents of maple sugar are unknown. Herein, 30 phenolic compounds, <b>1</b>–<b>30</b>, primarily lignans, were isolated and identified (by HRESIMS and NMR) from maple sugar. The isolates included the phenylpropanoid-based lignan tetramers (<i>erythro</i>,<i>erythro</i>)-4″,4‴-dihydroxy-3,3′,3″,3‴,5,5′-hexamethoxy-7,9′;7′,9-diepoxy-4,8″;4′,8‴-bisoxy-8,8′-dineolignan-7″,7‴,9″,9‴-tetraol, <b>29</b>, and (<i>threo</i>,<i>erythro</i>)-4″,4‴-dihydroxy-3,3′,3″,3‴,5,5′-hexamethoxy-7,9′;7′,9-diepoxy-4,8″;4′,8‴-bisoxy-8,8′-dineolignan-7″,7‴,9″,9‴-tetraol, <b>30</b>, neither of which have been identified from maple sap or maple syrup before. Twenty of the isolates (selected on the basis of sample quantity available) were evaluated for their potential biological effects against lipopolysaccharide-induced inflammation in BV-2 microglia in vitro and juglone-induced oxidative stress in Caenorhabditis elegans in vivo. The current study increases scientific knowledge of possible bioactive compounds present in maple-derived foods including maple sugar

Indazole-Type Alkaloids from <i>Nigella sativa</i> Seeds Exhibit Antihyperglycemic Effects via AMPK Activation in Vitro

Six rare naturally occurring indazole-type alkaloids including two new compounds, 17-<i>O</i>-(β-d-glucopyranosyl)-4-<i>O</i>-methylnigellidine (<b>1</b>) and nigelanoid (<b>2</b>), and four known compounds (<b>3</b>–<b>6</b>) were isolated from a defatted extract of <i>Nigella sativa</i> (black cumin) seeds. 17-<i>O</i>-(β-d-Glucopyranosyl)-4-<i>O</i>-methylnigellidine (<b>1</b>) increased glucose consumption by liver hepatocytes (HepG2 cells) through activation of AMP-activated protein kinase (AMPK). Also, this is the first report of compounds <b>4</b> and <b>6</b> from a natural source

Antidiabetic Ellagitannins from Pomegranate Flowers: Inhibition of α‑Glucosidase and Lipogenic Gene Expression

Two new ellagitannins containing a rare 3-oxo-1,3,3a,8b-tetrahydrofuro[3,4-<i>b</i>]benzofuran moiety, namely punicatannins A (<b>1</b>) and B (<b>2</b>), were isolated from pomegranate (<i>Punica granatum</i>) flowers. Their structures with absolute configuration were determined by detailed analysis of spectroscopic data, electronic circular dichroism (ECD) calculation, and chemical hydrolysis. A plausible biogenetic route involving a key enzymatic 1,4-Michael addition is proposed. Punicatannin A showed potent inhibition of α-glucosidase and lipogenic gene expression

Fluvirosaones A and B, Two Indolizidine Alkaloids with a Pentacyclic Skeleton from <i>Flueggea virosa</i>

Fluvirosaones A (<b>1</b>) and B (<b>2</b>), together with virosecurinine (<b>3</b>), were isolated from <i>Flueggea virosa</i>. Their structures were determined by physical, spectroscopic, and X-ray analysis and confirmed through comparison of the calculated and experimental ¹³C NMR and electronic circular dichroism (ECD) data. Compounds <b>1</b> and <b>2</b> represent the first examples of a pentacyclic <i>Securinega</i> alkaloid containing a pentacyclic system and an α,β-unsaturated ketone. Plausible biogenetic pathways of compounds <b>1</b> and <b>2</b> are proposed

New Sesquiterpenoids from <i>Eugenia jambolana</i> Seeds and Their Anti-microbial Activities

Twenty four sesquiterpenoids, <b>1</b>–<b>24</b>, including 11 new sesquiterpenoids, jambolanins A–K, and two new norsesquiterpenoids, jambolanes A and B, along with six known triterpenoids, were isolated from the seeds of <i>Eugenia jambolana</i> fruit. Their structures were elucidated on the basis of NMR and MS spectrometry data analysis. Among the isolates, compound <b>13</b> possessed a rare 6,7-<i>seco</i>-guaiene skeleton, and compounds <b>14</b> and <b>15</b> were norsesquiterpenoids containing a spiro[4.4]­nonane skeleton. Antimicrobial assay evaluation revealed that sesquiterpenoids, <b>4</b>, <b>5</b>/<b>6</b>, <b>17</b>, <b>19</b>, <b>21</b>, <b>23</b>, and <b>24</b> inhibited the growth of the Gram-positive bacterium, <i>Staphylococcus aureus</i>. The current study advances scientific knowledge of <i>E. jambolana</i> phytochemicals and suggests that its sesquiterpenoids may contribute, in part, to the anti-infective effects attributed to the edible fruit of this plant

Phloroglucinol Derivatives with Protein Tyrosine Phosphatase 1B Inhibitory Activities from <i>Eugenia jambolana</i> Seeds

Fifteen new phloroglucinol derivatives, jamunones A–O (<b>1–8</b> and <b>10–16</b>, respectively), along with one known analogue spiralisone C (<b>9</b>), were isolated from <i>Eugenia jambolana</i> seeds. Their structures were elucidated by detailed nuclear magnetic resonance and mass spectrometry spectroscopic data interpretation. Compounds <b>1–9</b>, <b>11</b>, <b>12</b>, and <b>14–16</b> inhibited protein tyrosine phosphatase 1B activity with IC₅₀ values ranging from 0.42 to 3.2 μM