Thiadiazole inhibitors: a patent review

ABSTRACT

Introduction: Four isomeric structures of thiadiazole motifs have outstanding pharmacological inhibitory applications are reported in this review. Thiadiazole nucleus is present in several biologically active natural products and commercial drugs. Most of thiadiazoles reported herein are emphasized to have broad spectrum of medicinal activities.

Areas covered: This review represents the recent inhibitory activities of thiadiazole isomeric scaffolds and their broad-spectrum biological applications published as full texts during 2010–2016 as well as the patents published during 2005–2016. The inhibition areas covered included anti-inflammatory, antimicrobial, antitumor, antioxidant, antitubercular, antiviral, antileishmanial, anticonvulsant, herbicidal and algicidal activities in addition to enzymes, human platelet aggregation and neuroprotective inhibitors.

Expert opinion: This survey revealed very interesting data about the applications of thiadiazoles, where some synthetic or natural thiadiazole derivatives were components of drugs available in the market. Many thiadiazole derivatives can be considered as lead compounds for drug synthesis. The most inhibitory active 1,3,4-thiadiazole compounds are those incorporating secondary alkyl(aryl)amido- and/or benzylthio(mercapto) groups at positions 2 and 5. Several thiadiazole derivatives demonstrated higher antibacterial, antitumor and antiviral activities than the standard drugs. Some thiadiazole derivatives exhibited high selective enzymes inhibitory activities based on the electronic properties of the substituents at positions 2 or 5.

KEYWORDS:

• Anti-inflammatory
• antimicrobial
• antitumor
• antiviral
• enzymes inhibitors
• thiadiazoles

Article highlights

• The pharmacological inhibitory activities of the four types: 1,2,3-, 1,2,4-, 1,2,5-, and 1,3,4-thiadiazole isomers and their derivatives are collected.

• The bulk of pharmacological publications are related to 1,3,4-thiadiazole derivatives however those of 1,2,5- thiadiazoles are the least reported ones.

• Most of the thiadiazole-based drugs in the market are of 1,3,4-thiadiazole isomer.

• Most of the inhibitory activities of the 1,3,4-thiadiazole derivatives are focused on antitumor activity

• The structure-activity relantionships (SAR) of some pharmacological activities are also reported.

• Thirty nine patents are cited among totally 134 references collected.

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Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Additional information

Funding

This paper was not funded.