Generation of vector beams of Bell-like states by manipulating vector vortex modes with plasmonic metasurfaces.

Metasurfaces with orthogonal nano-slit pairs arranged on spirals are proposed to generate vector beams (VBs) of Bell-like states and slanted polarizations. The design of the metasurfaces is based on the theoretically derived parameter condition for manipulation of the two vector vortex modes, which is satisfied by matching the three parameters of rotation order m, the spiral order n, and incident polarization helicity σ. The linear polarization states of the VBs are controlled by the initial orientation angle φ0 of slit pairs. VBs of satisfying quality are experimentally obtained, with the analytical and simulated results validated.

A hydrogen peroxide-activated Cu(II) pro-ionophore strategy for modifying naphthazarin as a promising anticancer agent with high selectivity for generating ROS in HepG2 cells over in L02 cells.

Targeting redox vulnerability of cancer cells by pro-oxidants capable of generating reactive oxygen species (ROS) has surfaced as an important anticancer strategy. Due to the intrinsic narrow therapeutic window and other dangerous side effects of ROS generation, it is highly needed and challenging to develop pro-oxidative anticancer agents (PAAs) with high selectivity for generating ROS in cancer cells. Herein we report a hydrogen peroxide (H2O2)-activated Cu(II) pro-ionophore strategy to develop naphthazarin (Nap) as such type of PAAs based on the H2O2-mediated conversion of boronate to free phenol. The boronate-protected Nap (PNap) can exploit increased levels of H2O2 in HepG2 cells to in situ release Nap followed by its efflux via conjugation with reduced glutathione (GSH), allowing that the Nap-GSH adduct works as a Cu(II) ionophore to induce continuously GSH depletion via a reduction-dependent releasing of Cu(I) by GSH. This strategy endows PNap with the unprecedented ability to hit multi-redox characteristics (increased levels of H2O2, GSH and copper) of HepG2 cells, leading to ROS generation preferentially in HepG2 cells along with their selective death.

Mechanistic Study on Gold-Catalyzed Highly Selective Hydroamination of Alkylidenecyclopropanes.

Density functional theory calculations have been carried out to study the mechanism of the gold-catalyzed highly selective hydroamination of alkylidenecyclopropanes. Two main mechanisms (i.e., double-bond activation-first and three-membered-ring activation-first mechanisms) have been examined. The double-bond activation-first mechanism results in the alkene hydroamination product, and it mainly consists of three steps: C-N bond formation, C-C bond rotation, and protodeauration (rate-determining step). Meanwhile, the three-membered-ring activation-first mechanism finally produces allylic amines, and it occurs via the ring-opening (rate-determining step), C-N bond formation, and protodeauration steps. The calculation results show good agreement with the experimental outcomes on the chemo-, regio-, and diastereoselectivity. On this basis, we found that the regioselectivity is caused by the C-C bond rotation step, while the diastereoselectivity is determined by both the C-C bond rotation and the protodeauration steps in the double-bond activation-first mechanism.

Influence of side chain structure changes on antioxidant potency of the [6]-gingerol related compounds.

[6]-Gingerol and [6]-shogaol are the major pungent components in ginger with a variety of biological activities including antioxidant activity. To explore their structure determinants for antioxidant activity, we synthesized eight compounds differentiated by their side chains which are characteristic of the C1-C2 double bond, the C4-C5 double bond or the 5-OH, and the six- or twelve-carbon unbranched alkyl chain. Our results show that their antioxidant activity depends significantly on the side chain structure, the reaction mediums and substrates. Noticeably, existence of the 5-OH decreases their formal hydrogen-transfer and electron-donating abilities, but increases their DNA damage- and lipid peroxidation-protecting abilities. Additionally, despite significantly reducing their DNA strand breakage-inhibiting activity, extension of the chain length from six to twelve carbons enhances their anti-haemolysis activity.

Tailoring 3,3'-dihydroxyisorenieratene to hydroxystilbene: finding a resveratrol analogue with increased antiproliferation activity and cell selectivity.

Four novel compounds were designed by "tailoring" 3,3'-dihydroxyisorenieratene (a natural carotenoid) based on an isoprene unit retention truncation strategy. Among them, the smallest molecule 1 (2,3,6,2',3',6'-hexamethyl-4,4'-dihydroxy-trans-stilbene) was concisely synthesized in a one-pot Stille-Heck tandem sequence, and surfaced as a promising lead molecule in terms of its selective antiproliferative activity mediated by blocking the NCI-H460 cell cycle in G1 phase. Additionally, theoretical calculations and cell uptake experiments indicate that the unique polymethylation pattern of compound 1 significantly induces a conformational change shift out of planarity and increases its cell uptake and metabolic stability. The observation should be helpful to rationally design resveratrol-inspired antiproliferative agents.

An effective strategy to develop active cinnamic acid-directed antioxidants based on elongating the conjugated chains.

To optimize antioxidant activity and lipophilicity of cinnamic acid derivatives (CAs) including ferulic acid, sinapic acid, 3,4-dimethoxycinnamic acid, and p-hydroxycinnamic acid, four analogs bearing an additional double bond between their aromatic ring and propenoic acid moiety were designed and synthesized based on the conjugated chain elongation strategy. The antioxidant performance of the CAs were investigated by 2,2'-diphenyl-1-picrylhydrazyl (DPPH)-scavenging, ferric reducing/antioxidant power, cyclic voltammetry, DNA strand breakage-inhibiting and anti-haemolysis activity assays. It was found that CAs with elongation of conjugated chains display increased DPPH-scavenging, DNA strand breakage-inhibiting and anti-haemolysis activities as compared to their parent molecules, due to their improved hydrogen atom-donating ability and lipophilicity. Overall, this work highlights an effective strategy to develop potential CA-directed antioxidants by elongating their conjugated chain.

[Suppression of murine EAE by triptolide is related to downregulation of INF-gamma and upregulation of IL-10 secretion in splenic lymphocytes].

AIM: To explore the therapeutic effectivity and the possible mechanism of triptolide (Tri) on experimental autoimmune encephalomyelitis (EAE). METHODS: All female C57BL/6 mice were randomly divided into EAE group (28), Tri treated group (20) and adjuvant group (18). Mice in EAE and treated groups were immunized with myelin oligodendrocyte glycoprotein peptides 35-55 (MOG(35-55);), adjuvant group was injected at the same time, but instead of MOG(35-55); with normal saline. Tri was intraperitoneally injected in the dosage of 100 microg/(kg.d) in treated group on day 5 post-immunization (p.i.), and mice in EAE and adjuvant group injected with normal saline as control. The clinical feature and pathological changes were observed and the splenic lymphocytes were prepared on days 18-20 p.i. The cell cultures were divided into the control group (only 200 microL of cell suspension) and the experimental group (cell suspension in the presence of 10 mg/L MOG(35-55);). Then all of them were inoculated in 96-well flat-bottom plates under 37 degrees Celsius, 50 mL/L CO(2);. After 48 h, the proliferation assay was determined by MTT, and the supernatants were harvested for the detection of INF-gamma, IL-17, IL-10 and IL-4 by ELISA. RESULTS: Tri treatment showed an significantly protective action on EAE. After the intervention of Tri, the levels of IL-10 were increased (P<0.05), but the secretion of INF-gamma and proliferation response of splenic lymphocytes induced by MOG(35-55); were statistically significantly inhibited(P<0.05 and P<0.01, respectively). There were no influences on the amount of IL-17 and IL-4 by Tri. CONCLUSION: Tri is an effective drug in suppressing murine EAE. This suppression is supposed to be related to downregulation of INF-gamma and upregulation of IL-10 secretion in splenic lymphocytes.

A novel mutation in the second half of the keratin 17 1A domain in a large pedigree with delayed-onset pachyonychia congenita type 2.

Pachyonychia congenita type 2 (PC-2), also known as Jackson-Lawler type PC, is an autosomal dominant disorder characterized by hypertrophic nail dystrophy associated with focal keratoderma and multiple pilosebaceous cysts. We report a large Chinese pedigree of typical delayed-onset PC-2 that includes 19 affected members. Direct sequencing of PCR products revealed a novel heterozygous 325A-->G mutation in the affected members. This mutation predicts the substitution of asparagine by aspartic acid in codon 109 (N109D) located in the second half of the keratin 17 1A domain, where similar mutation in keratin 5 is associated with the mild Weber-Cockayne form of epidermolysis bullosa simplex.