The concept of isosterism between relatively simple chemical entities was originally contemplated by James Moir in 1909, a notion further refined by H. G. Grimm’s hydride displacement law and captured more effectively in the ideas advanced by Irving Langmuir based on experimental observations. Langmuir coined the term “isostere” and, 18 years in advance of its actual isolation and characterization, predicted that the physical properties of the then unknown ketene would resemble those of diazomethane. The emergence of bioisosteres as structurally distinct compounds recognized similarly by biological systems has its origins in a series of studies published byHans Erlenmeyer in the 1930s, who extended earlier work conducted by Karl Landsteiner. Erlenmeyer showed that antibodies were unable to discriminate between phenyl and thienyl rings or O, NH, and CH2 in the context of artificial antigens derived by reacting diazonium ions with proteins, a process that derivatized the ortho position of tyrosine, as summarized in Figure 1 The term “bioisostere” was introduced by Harris Friedman in 1950 who defined it as compounds eliciting a similar biological effect while recognizing that compounds may be isosteric but not necessarily bioisosteric. This notion anticipates that the application of bioisosterism will depend on context, relying much less on physicochemical properties as the underlying principle for biochemical mimicry. Bioisosteres are typically less than exact structural mimetics and are often more alike in biological rather than physical properties. Thus, an effective bioisostere for one biochemical application may not translate to another setting, necessitating the careful selection and tailoring of an isostere for a specific circumstance. Consequently, the design of bioisosteres frequently introduces structural changes that can be beneficial or deleterious depending on the context, with size, shape, electronic distribution, polarizability, dipole, polarity, lipophilicity, and pKa potentially playing key contributing roles in molecular recognition and mimicry. In the contemporary practice of medicinal chemistry, the development and application of bioisosteres have been adopted as a fundamental tactical approach useful to address a number of aspects associated with the design and development of drug candidates. The established utility of bioisosteres is broad in nature, extending to improving potency, enhancing selectivity, altering physical properties, reducing or redirecting metabolism, eliminating or modifying toxicophores, and acquiring novel intellectual property. In this Perspective, some contemporary themes exploring the role of isosteres in drug design are sampled, with an emphasis placed on tactical applications designed to solve the kinds of problems that impinge on compound optimization and the long-term success of drug candidates. Interesting concepts that may have been poorly effective in the context examined are captured, since the ideas may have merit in alternative circumstances. A comprehensive cataloging of bioisosteres is beyond the scope of what will be provided, although a synopsis of relevant isosteres of a particular functionality is summarized in a succinct fashion in several sections. Isosterism has also found productive application in the design and optimization of organocatalysts, and there are several examples in which functional mimicry established initially in a medicinal chemistry setting has been adopted by this community.

Synopsis of some recent tactical application of bioisosteres in drug design.

Practical methodologies for the synthesis of indoles.

Jaguar is an ab initio quantum chemical program that specializes in fast electronic structure predictions for molecular systems of medium and large size. Jaguar focuses on computational methods with reasonable computational scaling with the size of the system, such as density functional theory (DFT) and local second-order Moller–Plesset perturbation theory. The favorable scaling of the methods and the high efficiency of the program make it possible to conduct routine computations involving several thousand molecular orbitals. This performance is achieved through a utilization of the pseudospectral approximation and several levels of parallelization. The speed advantages are beneficial for applying Jaguar in biomolecular computational modeling. Additionally, owing to its superior wave function guess for transition-metal-containing systems, Jaguar finds applications in inorganic and bioinorganic chemistry. The emphasis on larger systems and transition metal elements paves the way toward developing Jaguar for its use in materials science modeling. The article describes the historical and new features of Jaguar, such as improved parallelization of many modules, innovations in ab initio pKa prediction, and new semiempirical corrections for nondynamic correlation errors in DFT. Jaguar applications in drug discovery, materials science, force field parameterization, and other areas of computational research are reviewed. Timing benchmarks and other results obtained from the most recent Jaguar code are provided. The article concludes with a discussion of challenges and directions for future development of the program. © 2013 Wiley Periodicals, Inc.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/qua.24481

Jaguar: A high-performance quantum chemistry software program with strengths in life and materials sciences

A body fluid sampling system for use on a tissue site includes a single drive force generator. A plurality of penetrating members are operatively coupled to the force generator. The force generator moves each of the members along a path out of a housing with a penetrating member exit, into the tissue site, stops in the tissue site, and withdraws out of the tissue site. A flexible support member couples the penetrating members to define a linear array. The support member is movable and configured to move each of the penetrating members to a launch position associated with the force generator.

Method and Apparatus for Penetrating tissue

Invented are novel heterocyclic carboxamide compounds, the use of such compounds as inhibitors of protein kinase B activity and in the treatment of cancer and arthritis

Inhibitors of akt activity

The present invention provides compounds of Formula (I) or a stereoisomer or pharmaceutically acceptable salt or solvate form thereof, wherein the variables A, L, Z, X1, X2, X3, X4, and X5 are as defined herein. The compounds of Formula (I) are useful as selective inhibitors of serine protease enzymes of the coagulation cascade and/or contact activation system; for example thrombin, factor Xa, factor XIa, factor IXa, factor VIIa and/or plasma kallikrein. In particular, it relates to compounds that are selective factor XIa inhibitors. This invention also relates to pharmaceutical compositions comprising these compounds and methods of treating thromboembolic and/or inflammatory disorders using the same.

Five-membered heterocycles useful as serine protease inhibitors

Factor Xa inhibitors: next-generation antithrombotic agents

Azinothricin was isolated from the culture filtrate of Streptomyces sp. X-14950 in crystalline form. It represents a new type of hexadepsipeptide antibiotic as it contains a 19-membered cyclodepsipeptide ring composed of six unusual amino acids and bearing a novel C21 side chain. Azinothricin was identified as [(3S, 4S, 7R(S*), 10S, 17R, 20S, 23R)[2S(2'R*, 5'S*, 6'S*)3S*]]-α-ethyl - 6 -(3-ethyl-1, 5-dimethyl-4-oxo-1, 5-heptadienyl)- N-(1, 8, 14, 15, 18, 21, 27-heptaaza-21-hydroxy- 7-(1-hydroxyethyl) -2, 6, 9, 16, 19, 22-hexaoxo 4-isopropyl-20-(methoxymethyl)-17, 18-dimethyl-5-oxatricyclo[21.4.0.010, 15]heptacosan-3-yl)tetrahydro-α, 2-dihydroxy-5-methyl-2H-pyran-2-acetamide and is primarily active against Gram-positive microorganisms.

https://www.jstage.jst.go.jp/article/antibiotics1968/39/1/39_1_17/_pdf

Microbial products. VIII. Azinothricin, a novel hexadepsipeptide antibiotic.

Antithrombotic agents that are inhibitors of factor XIa (FXIa) have the potential to demonstrate robust efficacy with a low bleeding risk profile. Herein, we describe a series of tetrahydroquinoline (THQ) derivatives as FXIa inhibitors. Compound 1 was identified as a potent and selective tool compound for proof of concept studies. It exhibited excellent antithrombotic efficacy in rabbit thrombosis models and did not prolong bleeding times. This demonstrates proof of concept for the FXIa mechanism in animal models with a reversible, small molecule inhibitor.

Joanne M. Smallheer

Papers

Five-membered heterocycles useful as serine protease inhibitors

Factor Xa inhibitors: next-generation antithrombotic agents

Microbial products. VIII. Azinothricin, a novel hexadepsipeptide antibiotic.

Tetrahydroquinoline Derivatives as Potent and Selective Factor XIa Inhibitors.

Total synthesis of ()-dragmacidin : a cytotoxic bis(indole)alkaloid of marine origin