3 research outputs found
C<sub>14</sub>-Polyacetylene glucosides from <i>Codonopsis pilosula</i>
<div><p>Seven new C<sub>14</sub>-polyacetylene glucosides codonopilodiynosides A–G (<b>1</b>–<b>7</b>) were isolated from an aqueous extract of the <i>Codonopsis pilosula</i> roots. Their structures were determined by spectroscopic and chemical methods as (–)-(5<i>S</i>,6<i>E</i>,12<i>E</i>)-tetradeca-6,12-dien-8,10-diyn-1,5,14-triol 5-<i>O</i>-β-d-glucopyranoside (<b>1</b>), (–)-(5<i>S</i>,6<i>E</i>,12<i>E</i>)-tetradeca-6,12-dien-8,10-diyn-1,5,14-triol 5-<i>O</i>-β-d-glucopyranosyl-(1″ → 2′)-β-d-glucopyranoside (<b>2</b>), (–)-(5<i>S</i>,6<i>E</i>,12<i>E</i>)-tetradeca-6,12-dien-8,10-diyn-1,5,14-triol 5,14-di-<i>O</i>-β-d-glucopyranoside (<b>3</b>), (–)-(5<i>S</i>,6<i>E</i>)-tetradeca-6-en-8,10-diyn-1,5,14-triol 5-<i>O</i>-β-d-glucopyranoside (<b>4</b>), (–)-(5<i>S</i>,6<i>E</i>,12<i>E</i>)-tetradeca-6,12-dien-8,10-diyn-1,5-diol 5-<i>O</i>-β-d-glucopyranosyl-(1″ → 2′)-β-d-glucopyranoside (<b>5</b>), (–)-(6<i>S</i>,4<i>E</i>,12<i>E</i>)-tetradeca-4,12-dien-8,10-diyn-1,6-diol 6-<i>O</i>-β-d-glucopyranosyl-(1″ → 2′)-β-d-glucopyranoside (<b>6</b>), and (–)-(5<i>S</i>,6<i>E</i>)-tetradeca-6-en-1,5-epoxy-8,10-diyn-14-ol 14-<i>O</i>-β-d-glucopyranosyl-(1″ → 2′)-β-d-glucopyranoside (<b>7</b>), respectively. The absolute configurations of <b>1</b>–<b>7</b> were assigned by enzymatic hydrolysis followed by isolation of glucose and aglycones (<b>1a</b> and <b>4a</b>–<b>7a</b>), and subsequent comparison of specific rotation, TLC, and <sup>1</sup>H NMR data of the glucose with an authentic sugar sample and application of modified Mosher's method based on the MPA determination rule of Δδ<sup><i>RS</i></sup> values for <b>1a</b> and <b>4a,</b> and Δδ<sup><i>S</i></sup> values for <b>6a</b>. The configuration of <b>7</b> was assigned by electronic circular dichroism calculations based on the quantum-mechanical time-dependent density functional theory.</p></div
Diglycosidic indole alkaloid derivatives from an aqueous extract of <i>Isatis indigotica</i> roots
<p>Six new indole alkaloid diglycosides named isatigotindolediosides A-F (<b>1–6</b>), along with three known analogs (<b>7–9</b>), were isolated from an aqueous extract of the <i>Isatis indigotica</i> roots (ban lan gen). Their structures including the absolute configurations were determined by comprehensive spectroscopic data analysis, combined with enzyme or acid hydrolysis, and comparison of experimental circular dichroism (CD) and calculated electronic circular dichroism (ECD) spectra. In the preliminary assays, compounds <b>3</b>, <b>5</b>, and <b>8</b> showed antiviral activity against Coxsackie virus B3.</p
4-Hydroxybenzyl-substituted glutathione derivatives from <i>Gastrodia elata</i>
<div><p>Seven new 4-hydroxybenzyl-substituted glutathione derivatives (<b>2</b>–<b>8</b>), together with a known analogue (<b>1</b>), were isolated from the aqueous extract of <i>Gastrodia elata</i> Blume rhizomes. Their structures were determined by using spectroscopic and chemical methods. The absolute configurations of <b>1</b>–<b>8</b> were assigned by using Marfey's method, combined with comparing the NMR and CD spectroscopic data of sulfoxide moieties in <b>3</b>–<b>6</b> with those of <i>S</i>-(4-hydroxybenzyl)cysteine sulfoxide stereoisomers (<b>9</b>–<b>12</b>) synthesized as authentic samples. The configurations of <b>9</b>–<b>12</b> were confirmed by electronic CD calculations based on the quantum-mechanical time-dependent density functional theory. Furthermore, the structures of <b>1</b>, <b>3</b>, <b>5</b>, <b>7</b>, and <b>8</b> were verified by synthesis. Compound <b>3</b> was active against serum deprivation-induced PC12 cell damage and synthetic <b>9</b>–<b>14</b> exhibited activity against Fe<sup>2+</sup>-cysteine induced rat liver microsomal lipid peroxidation.</p></div