Current Medicinal Chemistry (v.23, #1)

Meet Our Editorial Board Member by Vito Ferro (1-1).

Foreword by Atta- ur- Rahman (2-2).

Engineering Nanomedicines to Overcome Multidrug Resistance in Cancer Therapy by Giovanni L. Beretta, Francesca Cavalieri (3-22).
Drug resistance to conventional antitumor drugs represents one of the major causes of treatment failure in patients affected by tumors. Two main types of drug resistance to anticancer drugs are found in tumors, namely intrinsic resistance, in which tumor cells are inherently resistant to chemotherapy, and acquired resistance, which results from previous drug exposure. Tumor cells resistant to a chemotherapeutic agent become cross-resistant to both similar and structurally unrelated classes of antitumor drugs, a biological mechanism known as multi drug resistance (MDR). Among the strategies considered to overcome MDR, nanovector-mediated drug administration represents an innovative and promising alternative. In this review, we report a number of nanovectors including polymer-drug conjugates, polymeric micelles, nanotubes, LbL nanocapsules, and silica and gold nanoparticles. These systems are designed for the efficient delivery of anthracyclines, vinca alkaloids, taxanes, and others drugs. The development of these nanovectos to specifically overcome MDR and their mechanisms of action are covered and discussed. Finally, we discuss challenges and opportunities for further development of nanodevices-based chemotherapies to circumvent MDR through the design of nanovectors for the delivery of multiple cargoes.

Macrocyclic trichothecenes as antifungal and anticancer compounds by Maira Peres de Carvalho, Herbert Weich, Wolf-Rainer Abraham (23-35).
Trichothecenes are sesquiterpenoid metabolites produced by fungi and species of the plant genus Baccharis, family Asteraceae. They comprise a tricyclic core with an epoxide at C-12 and C-13 and can be grouped into non-macrocyclic and macrocyclic compounds. While many of these compounds are of concern in agriculture, the macrocyclic metabolites have been evaluated as antiviral, anti-cancer, antimalarial and antifungal compounds. Some known cytotoxic responses on eukaryotic cells include inhibition of protein, DNA and RNA syntheses, interference with mitochondrial function, effects on cell division and membranes. These targets however have been elucidated essentially employing non-macrocyclic trichothecenes and only one or two closely related macrocyclic compounds. For several macrocyclic trichothecenes high selectivity against fungal species and against cancer cell lines have been reported suggesting that the macrocycle and its stereochemistry are of crucial importance regarding biological activity and selectivity. This review is focused on compounds belonging to the macrocyclic type, where a cyclic diester or triester ring binds to the trichothecane moiety at C-4 and C- 15 leading to natural products belonging to the groups of satratoxins, verrucarins, roridins, myrotoxins and baccharinoids. Their biological activities, cytotoxic mechanisms and structure-activity relationships (SAR) are discussed. From the reported data it becomes evident that even small changes in the molecules can lead to pronounced effects on biological activity or selectivity against cancer cells lines. Understanding the underlying mechanisms may help to design highly specific drugs for cancer therapy.

Leveraging NMR and X-ray Data of the Free Ligands to Build Better Drugs Targeting Angiotensin II Type 1 G-Protein Coupled Receptor by Tahsin F. Kellici, Dimitrios Ntountaniotis, Eftichia Kritsi, Maria Zervou, Panagiotis Zoumpoulakis, Constantinos Potamitis, Serdar Durdagi, Ramin Ekhteiari Salmas, Gizem Ergun, Ebru Gokdemir, Maria Halabalaki, Ioannis P. Gerothanassis, George Liapakis, Andreas Tzakos, Thomas Mavromoustakos (36-59).
The angiotensin II type 1 receptor (AT1R) has been recently crystallized. A new era has emerged for the structure-based rational drug design and the synthesis of novel AT1R antagonists. In this critical review, the X-ray crystallographic data of commercially available AT1R antagonists in free form are analyzed and compared with the conformational analysis results obtained using a combination of NMR spectroscopy and Molecular Modeling. The same AT1R antagonists are docked and compared in terms of their interactions in their binding site using homology models and the crystallized AT1R receptor. Various aspects derived from these comparisons regarding rational drug design are outlined.

Familial Mediterranean Fever (FMF) is a rare autosomal recessive autoinflammatory disorder involving the innate immunity and affecting almost exclusively populations with Mediterranean origin. Clinical features include recurrent episodes of fever, leukocitosis, serositis (peritonitis or pleuritis, arthritis), myalgia or erysipelas-like skin lesions, lasting 12-72 hrs. The MEFV gene mutations on chromosome 16p13.3 encodes the abnormal pyrin (marenostrin), a protein expressed in granulocytes, monocytes, serosal and synovial fibroblasts and involved in the activation of caspase-1 and the processing and release of active pro-inflammatory IL-1?. Since the first report in 1972, maintenance therapy with colchicine, a tricyclic neutral alkaloid, remains the mainstay of treatment in symptomatic FMF patients since it reduces the disease activity and prevents the development of secondary amyloidosis and renal damage. Adjunctive symptomatic therapy to colchicine includes nonsteroideal antinflammatory drugs and corticosteroids. In a small group of colchicine-intolerant or colchicine-resistant FMF patients, alternative treatments must be considered. Evolving experiences have focussed on the potential effectiveness of biologic agents working as TNF-? inhibitors (etanercept, infliximab), IL-1 trap (Rilonacept), IL-1 inhibitors (Anakinra, Canakinumab) and IL-6 receptor antibody (Tocilizumab). Interferon-? and thalidomide have also been employed in FMF patients. Still, clinical trials are mainly uncontrolled and restricted to few cases, thus requiring definitive conclusions. Old, and new treatments are discussed in the rare FMF disease, with the concept that any ideal treatment has to stand the test of time.

Vascular effects of flavonoids by Bruno Almeida Rezende, Aline Carvalho Pereira, Steyner F. Cortes, Virginia Soares Lemos (87-102).
Flavonoids are natural plant-derived polyphenolic compounds with various biological properties particularly in the cardiovascular system, including antiatherogenic, antioxidant, vasodilation, antihypertensive, and antiplatelet activities. These biological properties have been evaluated in several experimental and clinical studies. In addition, extensive reviews have discussed the antiatherogenic effect of these polyphenols. However, limited studies have investigated the potential therapeutic vascular effects of these compounds. This review brings together some recent studies, to establish the different signaling pathways involved in the molecular mechanisms that underlie the vasodilation induced by flavonoids.