Bioactive Asarone-Derived Phenylpropanoids from the Rhizome of <i>Acorus tatarinowii</i> Schott

Eight new (<b>1a</b>/<b>1b</b>, <b>2a</b>, <b>3a</b>, <b>4a</b>/<b>4b</b>, and <b>5a</b>/<b>5b</b>) and seven known (<b>2b</b>, <b>3b</b>, and <b>6</b>–<b>10</b>) asarone-derived phenylpropanoids, a known asarone-derived lignan (<b>12</b>), and four known lignan analogues (<b>11</b> and <b>13</b>–<b>15</b>) were isolated from the rhizome of <i>Acorus tatarinowii</i> Schott. The structures were elucidated via comprehensive spectroscopic analyses, modified Mosher’s method, and quantum chemical calculations. Compounds <b>1</b>–<b>8</b> were present as enantiomers, and <b>1</b>–<b>5</b> were successfully resolved via chiral-phase HPLC. Compounds <b>1a</b>/<b>1b</b> were the first cases of asarone-derived phenylpropanoids with an isopropyl C-3 side-chain tethered to a benzene core from nature. Hypoglycemic, antioxidant, and AChE inhibitory activities of <b>1</b>–<b>15</b> were assessed by the α-glucosidase inhibitory, ORAC, DPPH radical scavenging, and AChE inhibitory assays, respectively. All compounds except <b>3a</b> showed α-glucosidase inhibitory activity. Compound <b>3b</b> has the highest α-glucosidase inhibitory effect with an IC₅₀ of 80.6 μM (positive drug acarbose IC₅₀ of 442.4 μM). In the antioxidant assays, compounds <b>13</b>–<b>15</b> exhibited ORAC and DPPH radical scavenging activities. The results of the AChE inhibitory assay indicated that all compounds exhibited weak AChE inhibitory activities

Lycibarbarspermidines A–O, New Dicaffeoylspermidine Derivatives from Wolfberry, with Activities against Alzheimer’s Disease and Oxidation

Fifteen new dicaffeoylspermidine derivatives, lycibarbarspermidines A–O (<b>1</b>–<b>15</b>), were isolated from the fruit of Lycium barbarum (wolfberry). The structures were unambiguously determined by spectroscopic analyses and chemical methods. Dicaffeoylspermidine derivatives, a rare kind of plant secondary metabolites, are primarily distributed in the family of Solanaceae. Only six compounds were structurally identified, and all of them are acyclic aglycones. Compounds <b>1</b>–<b>15</b> are the first glycosidic products of dicaffeoylspermidine derivatives, and compounds <b>14</b>–<b>15</b> are the first cyclization products of dicaffeoylspermidine derivatives. Moreover, dicaffeoylspermidine derivatives were first isolated and identified from wolfberry. The short-term memory assay on a transgenic fly Alzheimer’s disease (AD) model showed that <b>1</b>–<b>15</b> exhibited different levels of anti-AD activity. The oxygen radical absorbance capacity assay revealed that <b>1</b>–<b>15</b> all displayed antioxidant capacity. Both anti-AD and antioxidant functions are related to the effects of wolfberry. Therefore, dicaffeoylspermidine derivatives are considered beneficial constituents responsible for the antiaging, neuroprotective, anti-AD, and antioxidant effects of wolfberry

Houttuynoid M, an Anti-HSV Active Houttuynoid from <i>Houttuynia cordata</i> Featuring a Bis-houttuynin Chain Tethered to a Flavonoid Core

Houttuynoid M (<b>1</b>), a new houttuynoid, and the related known compound houttuynoid A (<b>2</b>) were isolated from <i>Houttuynia cordata</i>. Their structures were defined using NMR data analysis, HR-MS^<i>n</i> experiment, and chemical derivatization. Houttuynoid M is the first example of a houttuynoid with a bis-houttuynin chain tethered to a flavonoid core. A putative biosynthetic pathway of houttuynoid M (<b>1</b>) is proposed. The anti-herpes simplex virus (anti-HSV) activities of <b>1</b> and <b>2</b> (IC₅₀ values of 17.72 and 12.42 μM, respectively) were evaluated using a plaque formation assay with acyclovir as the positive control

A microbial model of mammalian metabolism: biotransformation of 4,5-dimethoxyl-canthin-6-one using <i>Cunninghamella blakesleeana</i> CGMCC 3.970

<p>1. A filamentous fungus, <i>Cunninghamella blakesleeana</i> CGMCC 3.970, was applied as a microbial system to mimic mammalian metabolism of 4,5-dimethoxyl-canthin-6-one (<b>1</b>). Compound <b>1</b> belongs to canthin-6-one type alkaloids, which is a major bioactive constituent of a traditional Chinese medicine (the stems of <i>Picrasma quassioides</i>).</p> <p>2. After 72 h of incubation in potato dextrose broth, <b>1</b> was metabolized to seven metabolites as follows: 4-methoxyl-5-hydroxyl-canthin-6-one (<b>M1</b>), 4-hydroxyl-5-methoxyl-canthin-6-one (<b>M2</b>), canthin-6-one (<b>M3</b>), canthin-6-one <i>N</i>-oxide (<b>M4</b>), 10-hydroxyl-4,5-dimethoxyl-canthin-6-one (<b>M5</b>), 1-methoxycarbonl-<i>β</i>-carboline (<b>M6</b>), and 4-methoxyl-5-<i>O</i>-<i>β</i>-D-glucopyranosyl-canthin-6-one (<b>M7</b>).</p> <p>3. The structures of metabolites were determined using spectroscopic analyses, chemical methods, and comparison of NMR data with those of known compounds. Among them, <b>M7</b> was a new compound.</p> <p>4. The metabolic pathways of <b>1</b> were proposed, and the metabolic processes involved phase I (<i>O</i>-demethylation, dehydroxylation, demethoxylation, <i>N</i>-oxidation, hydroxylation, and oxidative ring cleavage) and phase II (glycosylation) reactions.</p> <p>5. This was the first research on microbial transformation of canthin-6-one alkaloid, which could be a useful microbial model for producing the mammalian phase I and phase II metabolites of canthin-6-one alkaloids.</p> <p>6. <b>1</b>, <b>M1</b>−<b>M5</b>, and <b>M7</b> are canthin-6-one alkaloids, whereas <b>M6</b> belongs to <i>β</i>-carboline type alkaloids. The strain of <i>Cunninghamella blakesleeana</i> can supply an approach to transform canthin-6-one type alkaloids into <i>β</i>-carboline type alkaloids.</p