Publications

There is an urgent unmet medical need for novel human immunodeficiency virus type 1 (HIV-1) inhibitors that are effective against a variety of NNRTI-resistance mutations. We report our research efforts aimed at discovering a novel chemotype of anti-HIV-1 agents with improved potency against a variety of NNRTI-resistance mutations in this paper. Structural modifications of the lead <b>K-5a2</b> led to the identification of a potent inhibitor <b>16c</b>. <b>16c</b> yielded highly potent anti-HIV-1 activities and improved resistance profiles compared with the approved drug etravirine. The co-crystal structure revealed the key role of the water networks surrounding the NNIBP for binding and for resilience against resistance mutations, while suggesting further extension of <b>16c</b> toward the NNRTI-adjacent site as a lead development strategy. Furthermore, <b>16c</b> demonstrated favorable pharmacokinetic and safety properties, suggesting the potential of <b>16c</b> as a promising anti-HIV-1 drug candidate.

This paper provides new insights into the fatigue properties of Selective Laser Molten components made from Ti6Al4V powder particles. The SLM-process parameters are optimized and high quality SLM-parts with a relative density of 99.7% are produced. Uniaxial fatigue experiments are then performed on notched and unnotched specimens and the endurance limits are determined using the staircase method and the theory of Dixon and Mood. The presented results indicate inferior fatigue strength in comparison with conventionally produced components from Ti6Al4V. Microstructural analysis shows that this is mainly due to the anisotropy in the microstructure and the weak grain boundaries between epitaxial grains. However, the failure mechanism is consistant leading to low statistical scatter in the fatigue data. Furthermore, the critical volume method and the critical distance theory have proven to be accurate and efficient design tools to account for the notch-effect in SLM-Ti6Al4V.

Currently, there has been considerable interest in the discovery of original molecules with broad-spectrum anti-HIV activity and favourable pharmacokinetic profiles, to be used as an alternative to the approved anti-HIV/AIDS drugs, should they fail as therapeutics. Five-membered azole heterocycles represent an important class of lead structures for novel anti-HIV drug development. They can serve as versatile building blocks to introduce different new functional groups, (i) as scaffolds to anchor these groups into the optimal space for interactions with the target, (ii) as basic pharmacophore elements to make hydrogen bonds or hydrophobic interaction for facilitating the spatial filling at the binding site, (iii) as ester surrogates to improve metabolic stability, or (iv) as pharmacophoric motif of metal coordination to coordinate metal ions (i.e. magnesium) within the active site of target (i.e. integrase). This article will summarize recent progress in the development of some azoles derivatives that inhibit the replication of HIV-1 and will illustrate the possible functional role(s) of the azole motif in the search for new anti-HIV drugs.

No abstract is provided for this article.

A series of polyoxometalates have been synthesized and evaluated for their inhibitory effects on HIV-1(III(B)) and HIV-1(ROD) replication in MT-4 cells. All compounds showed activity against HIV-1 and HIV-2, but the antiviral potency of the heteropolytungstates varied considerably depending on their chemical structure. The antiviral activity of single, double, and triple Keggin-type of compounds against HIV-1(III(B)) replication was comparable (IC(50): 0.4-0.5 microgram/mL), whereas HIV-2(ROD) appeared to become less sensitive with the increasing number of Keggin structures per compound. The same trend was observed for single and double Dawson structures. Some of these compounds were examined for their inhibitory effect on the replication of HIV-1(RF) and SIV(MAC(251)) in MT-4 cells. Their anti-HIV-1(RF) and anti-SIV(MAC(251)) potencies were comparable to those for the HIV-1(III(B)) or HIV-2(ROD) strain, respectively. The polyoxometalates represent a class of polyanionic compounds, which block the binding of the envelope glycoprotein gp120 of HIV to CD4(+) cells. The compounds interfered with the binding of anti-CD4 mAb to the OKT4A/Leu3a epitope of the CD4 receptor, compound 24 being the most active in this regard, and inhibited the binding of anti-gp120 mAb to infected MT-4 cells. None of the polyoxometalates inhibited the binding of a specific CXCR4 mAb to SUP-T1 cells, suggesting that they do not interact with CXCR4, the main co-receptor for T-tropic HIV strains, and thus act as virus binding, and not as fusion, inhibitors.