Welcome to the
drugs page, where you will learn more about the drugs that you are using in the Bound! card game.
Bound! is the protein-drug matching game that has you match protein cards (targets) with ligand cards (drugs): match the most pairs to be the winner!
The pair selected for this game are chosen at the intersection of two databases of crystal structures:
- The proteins (targets) are from the Protein Data Bank (PDB), a repository of 3D biolmolecular structures central to research and education.
- The ligands (drugs) are from the Cambridge Structural Database (CSD), a database of over 1 million curated small molecule organic and metal-organic structures, curated by the Cambridge Crystallographic Data Centre (CCDC).
In this page you will explore the drug structures from the CSD, if you are looking for the cards deck and the game rules, click on the button to go back to the main page.
The Bound! drugs
In each panel you will find:
- The drug common name.
- The CSD Refcode (what is a refcode?) with a link to the structure entry in the database, via our search tool Access Structure. In each structure page you will find more information and a 3D interactive representation. You can find a quick explainer on how to use the result viewer in Access Structures, if you need help in navigating the visualizer.
- An image of the drug molecule, created with the free version of the CCDC's visualization software Mercury. You will find below a legend reporting the elements colours used in the representation.
- A curiosity on the drug.
- The mechanism of action, which you can find explained on the right.
- The protein the ligand binds to, indicated with its PDB codes linking to the protein (target) entry in the Protein Data Bank.
Atom colours legend
Carbon - Grey, Hydrogen - White,
Nitrogen - Blue, Sulphur - Yellow,
Oxygen - Red, Fluorine - Lime Green,
Bromine - Brown, Chlorine - Green
Erythromycin 1 CSD Entry: QIKFEX 2 
Erythromycin was discovered in 1949 and has been commercially available since 1952 under the brand name Ilosone which refers to the Philippines region where Erythromycin was first isolated.
4 Mechanism of action:
Inhibitor 5 Binds to:
Ribosome (
4V7U)
6
Mechanisms of action
The term mechanism of action refers to the specific interaction through which a drug substance produces its pharmacological effect. The drug cards have a mechanism of action included.
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Inhibitor - A substance that binds to a target to reduce the target’s activity
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Antagonist - A drug that blocks or dampens a biological response by binding to and blocking a receptor rather than activating it (opposite is agonist)
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Agonist - An agonist is a chemical that activates a receptor to produce a biological response
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Activator - A DNA-binding protein that regulates one or more genes by increasing the rate of transcription
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Potentiator - A substance that enhances sensitization of an antigen
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Inducer - A molecule that regulates gene expression
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Modulator - A drug that binds to receptor at a different site from where an agonist binds and influences the function of the receptor
Explore
The drugs from the Bound! game are here! Get ready to explore the structures and learn new things! They are divided into the three categories based on what they are used for.
Or simply scroll through the rest of this webpage to explore all the ligands in the deck!
Antibiotics

Antibiotics are medicines that fight bacterial infections by killing the bacteria or inhibiting bacteria growth. Penicillin is the first class of antibiotics, discovered in 1928 by Alexander Fleming.
Erythromycin CSD Entry: QIKFEX
Erythromycin was discovered in 1949 and has been commercially available since 1952 under the brand name Ilosone which refers to the Philippines region where Erythromycin was first isolated.
Mechanism of action:
Inhibitor Binds to:
Bacterial Ribosome (
4V7U)
Novobiocin CSD Entry: NIVBIO
Novobiocin is a type of coumarin glycoside and is produced by the actinomycete Streptomyces niveus.
Mechanism of action:
Inhibitor Binds to:
DNA gyrase (
6RKW)
Rifapentine CSD Entry: MAFLAI
Despite being first prepared in 1965, Rifapentine was not approved for use by the FDA until 1998.
Mechanism of action:
Inhibitor Binds to:
Bacterial RNA polymerase (
2A69)
Bedaquiline CSD Entry: KIDWAW
Bedaquiline was first reported in 2004 and approved in 2012, making it the first new drug for tuberculosis in more than 40 years! Bedaquiline is marketed as the fumarate salt.
Mechanism of action:
Inhibitor Binds to:
Bacterial ATP synthase (
7JGA)
Piperacillin CSD Entry: PIPCIL
Piperacillin is derived from ampicillin and can be used in combination with other antibiotics such as tazobactam.
Mechanism of action:
Inhibitor Binds to:
Penicillin-binding protein (
6Q9N)
Antivirals

Antiviral medicines are used for treating viral infections. They can be broad-spectrum; targeting a wide range of viruses or specific. Idoxuridine is the first antiviral agent approved in 1962 for the treatment of viral infections.
Acyclovir CSD Entry: RIGDES
For the development of acyclovir, and other drugs, Gertrude B. Elion was awarded the Nobel Prize for Physiology or Medicine in 1988.
Mechanism of action:
Inhibitor Binds to:
Herpesvirus DNA polymerase (
7LUF)
Nevirapine CSD Entry: PABHIJ01
Nevirapine has been approved for use since 1996, it is marketed as the hemihydrate form.
Mechanism of action:
Inhibitor Binds to:
HIV reverse transcriptase (
7KJX)
Ritonavir CSD Entry: YIGPIO03
Production of ritonavir was impacted by the discovery of a less soluble polymorph which decreased bioavailability.
Mechanism of action:
Inhibitor Binds to:
HIV protease (
5V4Y)
Raltegravir CSD Entry: DIRCIS
Raltegravir was approved by the FDA in 2007, becoming the first example of an integrase inhibitor.
Mechanism of action:
Inhibitor Binds to:
HIV integrase (
6L0C)
Ribavirin CSD Entry: VIRAZL01
Ribavirin is a synthetic guanosine nucleoside for which two polymorphs are currently known.
Mechanism of action:
Inhibitor Antagonist Binds to:
RNA-dependent RNA polymerase (
3SFU)
Anticancer
Also known as antineoplastic drugs, they are used to treat cancer. They contain chemicals that kill cells that rapidly divide such as cancer cells. Cisplatin was the first metal based structure approved for cancer treatment.
Sorafenib CSD Entry: AKENOU
Sorafenib is marketed as the tosylate salt.
Mechanism of action:
Inhibitor Binds to:
B-Raf protein kinase (
1UWH)
Pentostatin CSD Entry: DFIMZP01
Pentostatin features a benzodiazepine motif which mimics the purine nucleobase.
Mechanism of action:
Inhibitor Binds to:
Adenosine deaminase (
6N9M)
Tamoxifen CSD Entry: TTAMOX01
Tamoxifen was first prepared by Dora Richardson in 1962 and features a triphenylethylene motif and is marketed at the citrate form.
Mechanism of action:
Agonist Antagonist Binds to:
Estrogen receptor beta (
2FSZ)
Paclitaxel CSD Entry: ARISOK
Paclitaxel was initially isolated from the bark of the Pacific yew tree.
Mechanism of action:
Inhibitor Binds to:
Microtubule (
Tubulin-beta) (
5SYF)
Vorinostat CSD Entry: IQILAW
Vorinostat has been approved for use by the FDA since 2006.
Mechanism of action:
Inhibitor Binds to:
Histone deacetylase 2 (
4LXZ)
Want to explore more?
Try our other fun activities! If you like card games, why not have fun with the Elements in Crystals Battlecards?