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SymeGold: Compound library and screening
A structurally distinctive library for high-quality hit discovery
A 78,000-compound screening library engineered for structural diversity, synthetic tractability and medicinal chemistry relevance, SymeGold delivers what conventional commercial libraries can’t.
Designed for discovery impact
SymeGold was built on six core design principles: Novelty, chemical tractability, structural integrity, physicochemical robustness, innovation and diversification potential. These pillars ensure a high-quality collection optimized for real-world screening success.
Medicinal chemistry-driven properties
Each compound is enumerated to align with key medicinal chemistry parameters, including polar surface area, molecular weight, aromatic character and MPO score, supporting screening libraries that balance diversity with developability.
SymeCycle macrocyclic subset
SymeCycle extends the collection with a growing set of macrocyclic structures designed to explore biologically relevant 3D space. Currently comprising 1,900 compounds and continually expanding, these molecules span molecular weights up to 640 Da with lipophilicity values from –2.5 to 5.2.
High-throughput screening with Axxam
SymeGold compounds can be screened through our strategic partner, Axxam S.p.A., a leader in assay development and high-throughput screening. Flexible screening options include:
- Transfer of validated assays to Axxam’s platform
- Use of existing assay formats
- Integration with Axxam collections such as AXXDiversity and RNA-targeted libraries
Validated hits can be rapidly accessed as powder aliquots or resynthesized using SymeGold’s core building blocks.
Rapid compound access and follow-up
All SymeGold powders are stored at –20 °C and shipped with a two-week turnaround. Key building blocks enable fast resynthesis and analogue expansion, ensuring seamless progression from screening to medicinal chemistry.
Built for scalability and continuity
SymeGold is managed for ease of access, reuse and scale-up — empowering your teams to validate hits quickly and transition smoothly into optimization workflows.
Related services
SymeGold modalities
Spirocyclic molecules
Limit the number of sp2 rich molecules. The SymeGold library addresses this by featuring 27,000 spirocyclic scaffolds, to avoid ‘molecular flatland’.
Pseudo natural compounds
SymeGold includes 4,000 pseudo-natural compounds, which utilize natural products as starting points for the generation of novel scaffolds.
Macrocyclic molecules
SymeGold incorporates 1,900 macrocyclic molecules that are now also available as a separate subset named SymeCycle.
Connected chemistry expertise
We combine medicinal chemistry, flexible synthetic chemistry, computational insights and specialty chemistry expertise to turn library data into clear next steps.
Early design and scalable synthesis are guided by real-time analysis, ensuring each compound series is purposeful and progression-ready.
The result is faster, more informed movement from discovery ideas to viable candidate molecules.
What do our partners say?
“I would like to extend my thanks for the excellent work Symeres has done in synthesizing the API for Part 1 of our project. Your communication throughout the process was outstanding, and the sense of urgency with which you operated allowed us to complete this phase promptly and efficiently.”
Leader
Large biotech
“They’ve always met or exceeded my expectations - that’s why I continue to come back, company after company, year after year.”
Allen Horhota, Vice-President Platform & Delivery
Seamless Therapeutics
“We’ve been with them…over 10 years. The cost, the flexibility - the value is just so strong. That’s why we’ve stuck with them.”
Senior Director, CMC
Biotech
“The progression was really phenomenal. I am truly impressed. There is a world of difference between you and other CROs.”
Start-up Founder
Biotech
“If the compound can be made, Symeres will undoubtedly find out a good way to make it.”
Dooyoung Jung, CEO
Pinotbio
“The team is making short work of these targets, so we will have to start thinking of some additional targets!”
Director
Biotech
“We are developing the most complex molecule that is built at this time in the world…We work with a lot of CROs, also chemistry CROs, and so far Symeres has done the best job with respect to transparency and also to troubleshoot the problems and find a solution. Over the years we have been really impressed with the work that Symeres has done.”
Founder
Biotech
“Through our dedicated FTE resource at Symeres we have achieved remarkable results, not only by developing a new “aspirational” synthetic route but also by significantly improving the current one to deliver a sustainable route for commercial production and giving us two options for late development.”
Associate Director
Large pharma, Europe
“A sign that things are going well - we keep coming to you. We’ve given Symeres five or six different projects already. That’s almost unheard of for us.“
Senior Director, Manufacturing
Top 10 global pharma
Your discovery and development partner
Symeres supports small-molecule programs from discovery through IND with openness, agility and scientific depth.
Our connected teams in Europe and North America have expertise across chemistry, biology, ADME and development and share data transparently, adapt quickly to new results, and stay accountable from first experiments to IND, to keep your progress clear, connected and continuous.
Resources we think you'll love
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CDMO red flags you can’t ignore: Undefined or shifting project scope
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Accelerating chemical innovation: Unveiling Symeres’ parallel chemistry
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Optimizing solid-state properties and enhancing API bioavailability through physicochemical prediction
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Stable isotope-labeled compounds
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Unlocking the potential of high-throughput screening: Symegold library design and expansion insights
Interviews
Insights into drug discovery and development 2025
Interviews
Interview with the computer-aided drug design (CADD) department
Interviews
Meet the Organix Director, Mario Gonzalez
Interviews
Interview with the new Managing Director of Symeres Groningen
Interviews
An interview with Yadan Chen and Paul O’Shea
Interviews
An interview with Anu Mahadevan and Paul Blundell
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Crystalline and liquid crystalline 25-hydroxy-cholest-5-en-3-sulfate sodium and methods for preparing same
Webinar | On-demand
In vivo pharmacokinetic experiments in preclinical drug development
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Accelerating medicinal chemistry by rapid analoging
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Solid-state chemistry part II: Optimal form selection by controlled crystallization
Webinar | On-demand
Route scouting for kilogram-scale manufacturing of APIs
Webinar | On-demand
Solid-state chemistry part I: Introduction
Speak with our SymeGold experts
See how we can support the discovery and development of your next breakthrough.