Li-Jun Wang

A Biocompatible Fluorescent Ink Based on Water‐Soluble Luminescent Carbon Nanodots

Carbon nanodots (C-dots) are fascinating carbon materialsthat are attracting increasing interest because they possessdistinct benefits, such as chemical inertness, a lack of opticalblinking, low photobleaching, low cytotoxicity, and excellentbiocompatibility, compared with organic dyes and othersemiconductor nanodots with heavy metal cores.

Anti‐Hepatitis B Virus Active Lactones from the Traditional Chinese Herb: Swertia mileensis

Swerilactonesu2005H-K (1-4), which are four novel lactones with an unprecedented C29 skeleton, were isolated from Swertia mileensis (Qing-Ye-Dan), an endemic Chinese herb used for treating viral hepatitis. Their structures were determined by extensive spectroscopic and X-ray crystallographic diffraction analyses. Swerilactonesu2005H-K exhibit potent anti-hepatitis B virus activity against HBV DNA replication with IC(50) values ranging from 1.53 to 5.34u2005μM. For the first time, a plausible biogenetic pathway for swerilactonesu2005H-K, together with the previously reported swerilactonesu2005A-D is proposed. From a biogenetic point of view, swerilactonesu2005A-D are ascribed as secoiridoid dimers, and swerilactonesu2005H-K as secoiridoid trimers.

Evolution from Lyotropic Liquid Crystal to Helical Fibrous Organogel of an Achiral Fluorescent Twin-Tapered Bi-1,3,4-oxadiazole Derivative

We report an unprecedented hierarchical self-assembly of an achiral twin-tapered bi-1,3,4-oxadiazole derivative (2,2-bis(3,4,5-trioctanoxyphenyl)-bi-1,3,4-oxadiazole, BOXD-T8). This molecule can form a layer-structured lyotropic liquid crystal and further forms a helical fibrous organogel in DMF at concentrations above 0.6 wtu2009%. The self-assembly process of BOXD-T8 in DMF is accompanied by a change in its fluorescence. The pitches of the helical fibers are non-uniform, and both left- and right-handed helical fibers are observed in equal quantities. Intermolecular π-π interactions between aromatic segments have been demonstrated to be the driving force for aggregate formation. This helical structure of BOXD-T8 is dependent on the solvent, concentration, and the layer-structured intermediate liquid-crystalline state.

Synthesis, structure-activity relationships and biological evaluation of dehydroandrographolide and andrographolide derivatives as novel anti-hepatitis B virus agents

Dehydroandrographolide and andrographolide, two natural diterpenoids isolated from Andrographis paniculata possessed activity against HBV DNA replication with IC50 values of 22.58 and 54.07μM and low SI values of 8.7 and 3.7 in our random assay. Consequently, 48 derivatives of dehydroandrographolide and andrographolide were synthesized and evaluated for their anti-HBV properties to yield a series of active derivatives with lower cytotoxicity, including 14 derivatives against HBsAg secretion, 19 derivatives against HBeAg secretion and 38 derivatives against HBV DNA replication. Interestingly, compound 4e could inhibit not only HBsAg and HBeAg secretions but also HBV DNA replication with SI values of 20.3, 125.0 and 104.9. Furthermore, the most active compound 2c with SI value higher than 165.1 inhibiting HBV DNA replication was revealed with the optimal logP value of 1.78 and logD values. Structure-activity relationships (SARs) of the derivatives were disclosed for guiding the future research toward the discovery of new anti-HBV drugs.

Design, synthesis, and molecular hybrids of caudatin and cinnamic acids as novel anti-hepatitis B virus agents

n Abstractn n Forty-six conjugated derivatives of caudatin with substituted cinnamic acids were synthesized, and their anti-hepatitis B virus (HBV) activity was evaluated in HepG 2.2.15 cells. Most of the derivatives exhibited potent anti-HBV activity, especially inhibiting the HBV DNA replication with the IC50 values from 2.44 to 22.89 μΜ. Compound 18 showed significant activity against the secretion of HBsAg, HBeAg, and HBV DNA replication with IC50 values of 5.52, 5.52, 2.44 μΜ, respectively, and had good safety (LD50xa0>xa01250xa0mg/kg) according to the acute toxicity study. Preliminary mechanism investigation suggested that compound 18 exerted antivirus effects via interfering HBV X promoter and enhancer I to influence HBV transcriptions.n n

Synthesis, biological evaluation and structure–activity relationships of glycyrrhetinic acid derivatives as novel anti-hepatitis B virus agents

Fifty-seven derivatives of glycyrrhetinic acid (GA) were synthesized, and their anti-hepatitis B virus (HBV) activity was evaluated in HepG 2.2.15 cells. Among them, sixteen compounds showed greater anti-HBV activity than GA, especially, compounds 29, 32, 35, 41 exhibited significantly inhibitory activities against HBV DNA replication with IC(50) values of 5.71, 5.36, 8.90 and 9.08 μM, respectively. The structure-activity relationships (SARs) of GA derivatives were discussed for exploring novel anti-HBV agents.

Two dimensional directed π–π interactions in a linear shaped bi-1,3,4-oxadiazole derivative to achieve organic single crystal with highly polarized fluorescence and amplified spontaneous emissions

We report the role of the molecular structure and molecular interactions of linear shaped bi-1,3,4-oxadiazole derivatives (BOXD-n) on their self-assembly behaviors and optical properties. The terminal chains of BOXD-n (n = 1, 4) play an important role in molecular self-assembling and their optical properties. High fluorescence efficiency (ΦF = 56%) was observed in BOXD-4 single crystal, while relatively low fluorescence efficiency (ΦF = 21%) was observed in BOXD-1 single crystal. Highly polarized fluorescence (Imax/Imin of 23) and deep blue ASE (λ = 403 nm, threshold of about 20 kW cm−2) were observed in BOXD-4 single crystal, in which molecules uniaxially J-type aggregate through both face-to-face and edge-to-edge π–π interactions between 1,3,4-oxadiazole rings and phenyl rings. No polarized fluorescence or ASE phenomenon was observed in BOXD-4 vacuum evaporated films.

Synthesis, structure-activity relationships and biological evaluation of caudatin derivatives as novel anti-hepatitis B virus agents.

A series of caudatin derivatives were synthesized, and their anti-hepatitis B virus (HBV) activity was evaluated in HepG 2.2.15 cells. Most of the 3-O-substituted caudatin derivatives showed effective anti-HBV activity. Among the tested compounds, six compounds (2e-2h, 2l, 2r) exhibited significantly inhibitory activity against HBV DNA replication with IC(50) values in the range of 2.82-7.48 μM. Interestingly, two compounds (2e, 2f) had potent activity inhibiting not only the secretion of HBsAg (IC(50)=18.68 μM, 21.71 μM), HBeAg (IC(50)=13.16 μM, 33.73 μM), but also HBV DNA replication (IC(50)=7.48 μM, 3.63 μM). The structure-activity relationships (SARs) of caudatin derivatives had been discussed, which were useful for caudatin derivatives to be explored and developed as novel anti-HBV agents.

Waveguide and ultralow-threshold amplified spontaneous emission in an aligned ordered solid state based on a highly fluorescent twin-tapered bi-1,3,4-oxadiazole derivative.

Strong fluorescence and amplified spontaneous emissions (ASE) both in solution and aligned ordered solid state were observed from a twin-tapered bi-1,3,4-oxadiazole derivative, which could be used in preparing functional supramolecular architectures with ultralow-threshold ASE.

Synthesis of hemslecin A derivatives: a new class of hepatitis B virus inhibitors.

A series of hemslecin A derivatives were synthesized and evaluated for their anti-hepatitis B virus (HBV) activities, namely, inhibiting the secretion of hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), and HBV DNA replication on HepG 2.2.15 cells. Most of the derivatives showed enhanced anti-HBV activities, of which compounds A1-A7, B5, C and E exhibited significant activities inhibiting HBV DNA replication with IC(50) values of 2.8-11.6 μM, comparable to that of the positive control, tenofovir. Compounds A1-A3, A5, B5, and C displayed low cytotoxicities, which resulted in high SI values of 89.7, 55.6, 77.8, >83.4, >55.8, and >150.5, respectively.