Three new triterpenoid saponins from <i>Albizia julibrissin</i>

<p>Three new triterpenoid saponins, julibrosides A₅–A₇ (<b>1–3</b>), together with five known saponins (<b>4–8</b>), were isolated from the stem bark of <i>Albizia julibrissin</i>. Their structures were elucidated on the basis of extensive spectroscopic data analysis of MS, 1D and 2D NMR, and chemical methods. Compounds <b>7</b> and <b>8</b> were isolated from the genus <i>Albizia</i> for the first time. The new compounds showed no cytotoxicity and anti-inflammatory activity.</p

Sesquiterpenoids from <i>Pilea cavaleriei</i>

One new cis p-coumaroyl copaborneol-type sesquiterpenoid (1), together with its known trans isomer (2) and six other known p-coumaroyl humulane-type sesquiterpenoids (3–8), were isolated from the whole plants of Pilea cavaleriei. Their structures were determined by spectroscopic data. Compounds 1–4 exhibited moderate antimycobacterial activity against Mycobacterium tuberculosis H37Rv.</p

Triterpenoids from the hook-bearing stems of <i>Uncaria rhynchophylla</i>

An unprescribed nortriterpenoid with an aromatic E ring, uncanortriterpenoid A (1), together with fourteen known triterpenoids (2–15), were isolated from the hook-bearing stems of Uncaria rhynchophylla Miq. Based on extensive spectroscopic analyses, the NMR data of 2, 5, and 10 in CD3OD were assigned for the first time, and the wrongly assigned δC of C-27 and C-29 of 2 were revised. Among the known compounds, 7, 13, and 15 were isolated from this species for the first time, and 15 represents the first lanostane triterpenoid bearing an extra methylidene at C-24 for the Rubiaceae family. Additionally, compounds 6 and 14 exhibited moderate ferroptosis inhibitory activity, with an EC50 value of 14.74 ± 0.20 μM for 6 and 23.11 ± 1.31 μM for 14.</p

Antenna enhanced infrared photoinduced force imaging in aqueous environment with super-resolution and hypersensitivity

Tip enhanced IR spectra and imaging have been widely used in cutting-edge studies for the in-depth understanding of the composition, structure and function of interfaces at the nanoscale. However, molecular monolayer sensitivity has only been demonstrated on solid/gas interfaces. In aqueous environment, the reduced sensitivity due to strong damping of the cantilever oscillation and background IR absorption extremely limits the practical applications of tip enhanced IR nanospectroscopy. Here, we demonstrate hypersensitive nanoscale IR spectra and imaging in aqueous environment with the combination of photoinduced force (PiF) microscopy and resonant antennas. The highly confined electromagnetic field inbetween the tip end and antenna extremely amplifies the photoinduced force to the detectable level, while the excitation via plasmon internal reflection mode minimizes the environmental absorption. A polydimethylsiloxane (PDMS) layer (~1-2 nm thickness) functionalized on the AFM tip has been successfully identified in water with antennas of different sizes. Sampling volume of ~604 chemical bonds from PDMS was demonstrated with sub-10 nm spatial resolution confirmed by electric (E) field distribution mapping on antennas, which strongly suggests the desired requirements for interfacial spectroscopy. This platform demonstrates for the first time the application of photoinduced force microscopy in aqueous environments, providing a brand-new configuration to achieve highly enhanced nanoscale IR signals, which is extremely promising for future research of interfaces and nanosystems in aqueous environments

Prenylated benzoic acid derivatives from the stem of <i>Euodia lepta</i>

Two new prenylated benzoic acid derivatives, leptoic acid A and (+)-S-anodendroic acid (1–2), along with one known compound, 2,2-dimethyl-2H-1-benzopyran-6-carboxylic acid (3) were isolated from the stem of Euodia lepta (spreng.) Merr. Their structures were elucidated on the basis of the chemical and spectroscopic evidence.</p

Neuroprotective Xanthone Glycosides from <i>Swertia punicea</i>

Two new dimeric xanthone O-glycosides, puniceasides A (1) and B (2), a new trimeric O-glycoside, puniceaside C (3), and two new trimeric C-glycosides, puniceasides D (4) and E (5), together with 12 known xanthones were isolated from the entire plant of Swertia punicea. The structures of 1−5 were determined by HRESIMS and NMR spectroscopic methods. Compounds 2, 6, and 7 exhibited potent neuroprotective activity against H2O2-induced PC12 cell damage

Three new compounds from <i>Dictamnus dasycarpus</i> and their anti-inflammatory activities

Three new compounds (1–3), named dasycarine G (1), dasycarether (2), and dasycarester (3), along with seven known compounds (4–10) obtained from the genus Dictamnus for the first time, were isolated from the root bark of Dictamnus dasycarpus. Their structures were elucidated on the basis of spectroscopic data (UV, IR, HR-ESI-MS, 1D and 2D NMR, and CD). In the in vitro assay, compounds 1, 5, 6, 9, and 10 exhibited NO inhibitory effects of LPS-induced BV-2 cells with IC50 values in the range of 10.4 μM to 27.2 μM.</p

3-Hydroxy-3-Methylglutaryl Flavonol Glycosides from <i>Oxytropis falcata</i>

Five new 3-hydroxy-3-methylglutaryl (HMG) flavonol 3-<i>O</i>-glycosides, named oxytroflavosides A–E (<b>1</b>–<b>5</b>), and two new rhamnocitrin 3-<i>O</i>-glycosides, oxytroflavosides F and G (<b>6</b> and <b>7</b>) were isolated from the n-BuOH-soluble fraction of an EtOH extract of <i>Oxytropis falcata</i> together with seven known kaempferol glycosides (<b>8</b>–<b>14</b>), of which six were isolated from the genus <i>Oxytropis</i> for the first time. The structures of these compounds were elucidated by spectroscopic techniques and chemical methods. The absolute configuration of HMG in compounds <b>1</b>–<b>5</b> was determined to be <i>S</i> through spectroscopic analysis of the mevalonamide obtained by amidation and reduction of the HMG moiety. Compounds <b>1</b>–<b>10</b> were evaluated for anti-inflammatory activities using lipopolysaccharide-induced RAW 264.7 cells, but none of them showed inhibitory effects on NO production

Additional file 7 of Whole-genome resequencing of wild and cultivated cannabis reveals the genetic structure and adaptive selection of important traits

Additional file 7: Fig. S1. Analysis of the differences in the main phenotypic characteristics between wild cannabisand cultivated cannabis. The data represent the means ± SDs. Significant differences were determined using GraphPad Prism 8 software (* indicates P <0.05; ** indicates P < 0.01; *** indicates P < 0.001; **** indicates P< 0.0001)

Additional file 2 of Whole-genome resequencing of wild and cultivated cannabis reveals the genetic structure and adaptive selection of important traits

Additional file 2: Table S2. Sequencing reads and mapping rate of 21 cannabis accessions