Reactive Spreading Dynamics of Molten Polymer Liquids

Despite the key to the adhesion between polymers and a plethora of materials, our understanding of reactive wetting is still rudimentary. In the present work, we report the reactive wetting dynamics of molten maleic anhydride-grafted polypropylene (MA-g-PP) liquids modeled by molecular-kinetic theory (MKT). The dependencies of the contact line friction (ζ) and viscosity (η) were compared for reactive and nonreactive wetting polymer systems. Compared with linear dependencies of ζ and η for the nonreactive wetting systems, the reactive wetting system presented a nonlinear relationship. In the capillary regime, the chemistry-affected regime is followed by a regime that is nearly not affected by chemical reactions, which is identified by the linear MKT. The formation of a new interface and the resulting entanglements of polymer chains in the chemistry-affected regime contribute to the dependence of ζ on η in the capillary regime

Rhodomollacetals A–C, PTP1B Inhibitory Diterpenoids with a 2,3:5,6-Di-<i>seco</i>-grayanane Skeleton from the Leaves of <i>Rhododendron molle</i>

Three novel diterpenoids with an unprecedented 2,3:5,6-di-<i>seco</i>-grayanane carbon skeleton, rhodomollacetals A–C (<b>1</b>–<b>3</b>), are isolated from the leaves of <i>Rhododendron molle</i>. Their structures are elucidated by comprehensive spectroscopic techniques and single-crystal X-ray diffraction. Rhodomollacetal A (<b>1</b>) possesses a novel <i>cis/cis/cis/cis</i>-fused 6/6/6/6/5 pentacyclic ring system, featuring an unprecedented 11,13,18-trioxa-pentacyclo [8.7.1.1^5,8.0^2,8.0^12,17]­nonadecane scaffold. Compounds <b>2</b> and <b>3</b> have a rare 4-oxatricyclo­[7.2.1.0^1,6]­dodecane moiety and a 2,3-dihydro-4<i>H</i>-pyran-4-one unit. Compounds <b>1</b>–<b>3</b> showed moderate PTP1B inhibitory activities, and their molecular dockings were investigated

Rhodomollanol A, a Highly Oxygenated Diterpenoid with a 5/7/5/5 Tetracyclic Carbon Skeleton from the Leaves of <i>Rhododendron molle</i>

A novel diterpenoid with an unprecedented carbon skeleton, rhodomollanol A (<b>1</b>), and a new grayanane diterpenoid, rhodomollein XXXI (<b>2</b>), were isolated from the leaves of <i>Rhododendron molle</i>. Their structures were elucidated using comprehensive spectroscopic methods and single-crystal X-ray diffraction. Compound <b>1</b> possesses a unique <i>cis</i>/<i>trans</i>/<i>trans</i>/<i>cis</i>/<i>cis</i>-fused 3/5/7/5/5/5 hexacyclic ring system featuring a rare 7-oxabicyclo[4.2.1]­nonane core decorated with three cyclopentane units. The plausible biosynthetic pathway for <b>1</b> was proposed. Compound <b>1</b> exhibited moderate PTP1B inhibitory activity

Acetylcholinesterase Inhibitory Alkaloids from the Whole Plants of <i>Zephyranthes carinata</i>

Eleven new alkaloids (<b>1</b>–<b>11</b>), classified as the 12-acetylplicamine (<b>1</b>), <i>N-</i>deformyl-<i>seco</i>-plicamine (<b>2</b>), plicamine (<b>3</b>–<b>6</b>), 4a-<i>epi</i>-plicamine (<b>7</b>), <i>seco</i>-plicamine (<b>8</b>), and lycorine (<b>9</b>–<b>11</b>) framework types, along with 15 known alkaloids (<b>12</b>–<b>26</b>) were isolated from the whole plants of <i>Zephyranthes carinata</i>. The structures of the new alkaloids <b>1</b>–<b>11</b> were established by extensive spectroscopic data interpretation. The absolute configurations of <b>9</b> and <b>10</b> were defined by single-crystal X-ray diffraction analysis. Zephycarinatines A (<b>1</b>), B (<b>2</b>), and G (<b>7</b>) represent the first examples of 12-acetylplicamine, <i>N-</i>deformyl-<i>seco</i>-plicamine, and 4a-<i>epi</i>-plicamine alkaloids, respectively. Alkaloids <b>6</b>, <b>11</b>, <b>17</b>, and <b>20</b>–<b>23</b> exhibited AChE inhibitory activities with IC₅₀ values ranging from 1.21 to 184.05 μM, and a preliminary structure–activity relationship is discussed

Anti-inflammatory Grayanane Diterpenoids from the Leaves of <i>Rhododendron molle</i>

Thirteen new grayanane diterpenoids (<b>1</b>–<b>13</b>), a new dimeric grayanane diterpenoid, bimollfoliagein A (<b>14</b>), and 15 known analogues (<b>15</b>–<b>29</b>) were isolated from the leaves of <i>Rhododendron molle</i>. The structures of the new compounds (<b>1</b>–<b>14</b>) were determined by extensive spectroscopic data interpretation. The absolute configurations of <b>1</b>–<b>3</b>, <b>7</b>, <b>8</b>, <b>16</b>, <b>18</b>, and <b>24</b> were defined by single-crystal X-ray diffraction analysis. Mollfoliagein A (<b>1</b>) represents the first example of a 2,3:11,16-diepoxy grayanane diterpenoid, featuring a <i>cis/trans/cis/cis/trans</i>-fused 3/5/7/6/5/5 hexacyclic ring system with a 7,13-dioxahexacyclo­[10.3.3.0^1,11.0^4,9.0^6,8.0^14,17]­octadecane scaffold. Diterpenoids <b>1</b>–<b>29</b> were evaluated for their anti-inflammatory activities in vitro, and <b>15</b>, <b>16</b>, <b>18</b>, <b>19</b>, <b>23</b>–<b>26</b>, <b>28</b>, and <b>29</b> exhibited significant inhibitory activities against nitric oxide production in lipopolysaccharide-induced RAW264.7 mouse macrophages with IC₅₀ values ranging from 2.8 to 35.4 μM. A preliminary structure–activity relationship for the anti-inflammatory activity of diterpenoids <b>1</b>–<b>29</b> is discussed

Acetylcholinesterase Inhibitory Alkaloids from the Whole Plants of <i>Zephyranthes carinata</i>

Eleven new alkaloids (<b>1</b>–<b>11</b>), classified as the 12-acetylplicamine (<b>1</b>), <i>N-</i>deformyl-<i>seco</i>-plicamine (<b>2</b>), plicamine (<b>3</b>–<b>6</b>), 4a-<i>epi</i>-plicamine (<b>7</b>), <i>seco</i>-plicamine (<b>8</b>), and lycorine (<b>9</b>–<b>11</b>) framework types, along with 15 known alkaloids (<b>12</b>–<b>26</b>) were isolated from the whole plants of <i>Zephyranthes carinata</i>. The structures of the new alkaloids <b>1</b>–<b>11</b> were established by extensive spectroscopic data interpretation. The absolute configurations of <b>9</b> and <b>10</b> were defined by single-crystal X-ray diffraction analysis. Zephycarinatines A (<b>1</b>), B (<b>2</b>), and G (<b>7</b>) represent the first examples of 12-acetylplicamine, <i>N-</i>deformyl-<i>seco</i>-plicamine, and 4a-<i>epi</i>-plicamine alkaloids, respectively. Alkaloids <b>6</b>, <b>11</b>, <b>17</b>, and <b>20</b>–<b>23</b> exhibited AChE inhibitory activities with IC₅₀ values ranging from 1.21 to 184.05 μM, and a preliminary structure–activity relationship is discussed

Dispersive Micro-Solid-Phase Extraction of Herbicides in Vegetable Oil with Metal–Organic Framework MIL-101

Dispersive microsolid-phase extraction based on metal–organic framework has been developed and applied to the extraction of triazine and phenylurea herbicides in vegetable oils in this work. The herbicides were directly extracted with MIL-101 from diluted vegetables oils without any further cleanup. The separation and determination of herbicides were carried out on high performance liquid chromatography. The effects of experimental parameters, including volume ratio of <i>n</i>-hexane to oil sample, mass of MIL-101, extraction time, centrifugation time, eluting solvent, and elution time were investigated. The Student’s <i>t</i> test was applied to evaluate the selected experimental conditions. The limits of detection for the herbicides ranged from 0.585 to 1.04 μg/L. The recoveries of the herbicides ranged from 87.3 to 107%. Our results showed that the present method is rapid, simple, and effective for extracting herbicides in vegetable oils