InChIs and SMILES from Erectile Dysfunction Drug Searches at ChemSpider

07 May

WARNING: This is an R-rated blog post and deals with issues related to sexual dysfunction. Do not read further if you are easily offended. If you choose to read from this point forward please do not raise objections later. You have been warned.

We’ve only had it up for six weeks but already it’s clear that sex is of interest on the ChemSpider website. Excuse me you say???

Yes indeed…as with the rest of the web the subject of the birds and the bees proliferates even onto the ChemSpider website. We expected to have people submitting crude comments to the blog, sending inappropriate emails to the domain and even attempting to flirt on the ChemSpider skype number. All happened. (Layla from Belgium..if you are reading I am happily married and you have been blocked). The interest in erectile dysfunction drugs at ChemSpider itself seems to actually be scientific in nature (well maybe).

One of the most common searches in the domain on erectile dysfunction (ED) chemicals is, in many ways to be expected, for Viagra. The searches have generally been by trade name but also structure-based searches of sildenafil. Viagra is not the only chemical of interest. Both Cialis and Levitra are also showing a number of hits. We’ve also seen inquiries for Yohimbine and Ginseng and we’re now waiting for a search on powdered rhino horn. Okay, so how many of these searches are by lay people and how many by chemists? If these searches are by non-chemists what are they trying to find out about these chemicals at ChemSpider? Are they looking for side effects, consumer reports, suppliers or prices? We certainly don’t advertise for the big drug companies so they are not being drawn to our site in this manner.

It’s unlikely that they have interest in the physicochemical properties. Maybe they are instead interested in the trade names, synonyms and systematic identifiers. It appears this may be so since a recent submission to the data curation section of ChemSpider commented that we were actually lacking certain synonyms for Viagra.


Maybe these searches were actually performed by chemists comparing what types of SMILES each of the erectile dysfunction drugs would deliver or even how big an InChI each had. Below are listed three of the most common ED drugs with their relative SMILES and InChIs. It is clear that Viagra gives bigger SMILES than either Levitra or Cialis and that Viagra also delivers more InChI than its competitors. This is a common situation for these systematic identifiers…the bigger the InChI the bigger the SMILES. There is no situation we are aware of where a small InChI doesn’t give rise to at least a little SMILES.


We have also noticed some combined searches occurring on ChemSpider :“ generally combinations of common drugs with erectile dysfunction drugs. For example, a) Viagra with Aspirin, b) Levitra with Glucosamine and c) Cialis with Atorvastatin. The purpose of such combinations is clear: For a) performance without a headache, b) the possibility of sexual enhancement while simultaneously preventing stiffness in the joints (isn’t that an oxymoron) and c) improved sexual performance combined with anti-stroke (personally I believe pro-stroke makes more sense in this case).

It was recently brought to our attention that Bremelanotide, a derivative of Melanotan, is about to go into a phase III clinical trial. Originally, the peptide Melanotan II that bremelanotide was developed from was tested as a sunless tanning agent. In initial testing, Melanotan II did induce tanning but additionally caused sexual arousal and spontaneous erections as unexpected side effects in eight out of the ten original male volunteer test subjects. Clearly this caused concern on the beaches and likely gave rise to a few SMILES as a result (excuse the pun). As shown below this complex structure is far more complex in nature than the other commercial ED treatments and may have the side benefit of providing a tan!



A Large InChI from Bremelanotide Clearly Also Gives Large SMILES

With the ongoing surge of interest in the erectile dysfunction chemistry exposed at ChemSpider the team is presently considering the formation of a subset database for submission to PubChem. This will likely get submitted as the NAKED Chemicals database since the database will contain the Nomenclature, Acronyms and Knowledge of Erectile Dysfunction drugs, metabolites and related materials. Considering the usage of these materials the NAKED Chemicals database will likely arouse a lot of interest.


About tony

Antony (Tony) J. Williams received his BSc in 1985 from the University of Liverpool (UK) and PhD in 1988 from the University of London (UK). His PhD research interests were in studying the effects of high pressure on molecular motions within lubricant related systems using Nuclear Magnetic Resonance. He moved to Ottawa, Canada to work for the National Research Council performing fundamental research on the electron paramagnetic resonance of radicals trapped in single crystals. Following his postdoctoral position he became the NMR Facility Manager for Ottawa University. Tony joined the Eastman Kodak Company in Rochester, New York as their NMR Technology Leader. He led the laboratory to develop quality control across multiple spectroscopy labs and helped establish walk-up laboratories providing NMR, LC-MS and other forms of spectroscopy to hundreds of chemists across multiple sites. This included the delivery of spectroscopic data to the desktop, automated processing and his initial interests in computer-assisted structure elucidation (CASE) systems. He also worked with a team to develop the worlds’ first web-based LIMS system, WIMS, capable of allowing chemical structure searching and spectral display. With his developing cheminformatic skills and passion for data management he left corporate America to join a small start-up company working out of Toronto, Canada. He joined ACD/Labs as their NMR Product Manager and various roles, including Chief Science Officer, during his 10 years with the company. His responsibilities included managing over 50 products at one time prior to developing a product management team, managing sales, marketing, technical support and technical services. ACD/Labs was one of Canada’s Fast 50 Tech Companies, and Forbes Fast 500 companies in 2001. His primary passions during his tenure with ACD/Labs was the continued adoption of web-based technologies and developing automated structure verification and elucidation platforms. While at ACD/Labs he suggested the possibility of developing a public resource for chemists attempting to integrate internet available chemical data. He finally pursued this vision with some close friends as a hobby project in the evenings and the result was the ChemSpider database ( Even while running out of a basement on hand built servers the website developed a large community following that eventually culminated in the acquisition of the website by the Royal Society of Chemistry (RSC) based in Cambridge, United Kingdom. Tony joined the organization, together with some of the other ChemSpider team, and became their Vice President of Strategic Development. At RSC he continued to develop cheminformatics tools, specifically ChemSpider, and was the technical lead for the chemistry aspects of the Open PHACTS project (, a project focused on the delivery of open data, open source and open systems to support the pharmaceutical sciences. He was also the technical lead for the UK National Chemical Database Service ( and the RSC lead for the PharmaSea project ( attempting to identify novel natural products from the ocean. He left RSC in 2015 to become a Computational Chemist in the National Center of Computational Toxicology at the Environmental Protection Agency where he is bringing his skills to bear working with a team on the delivery of a new software architecture for the management and delivery of data, algorithms and visualization tools. The “Chemistry Dashboard” was released on April 1st, no fooling, at, and provides access to over 700,000 chemicals, experimental and predicted properties and a developing link network to support the environmental sciences. Tony remains passionate about computer-assisted structure elucidation and verification approaches and continues to publish in this area. He is also passionate about teaching scientists to benefit from the developing array of social networking tools for scientists and is known as the ChemConnector on the networks. Over the years he has had adjunct roles at a number of institutions and presently enjoys working with scientists at both UNC Chapel Hill and NC State University. He is widely published with over 200 papers and book chapters and was the recipient of the Jim Gray Award for eScience in 2012. In 2016 he was awarded the North Carolina ACS Distinguished Speaker Award.
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Posted by on May 7, 2007 in ChemSpider Chemistry


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