An evaluation of spirooxindoles as blocking agents of SARS-CoV-2 spike/ACE2 interaction: synthesis, biological evaluation and computational analysis
Bibliographic record
Abstract
Abstract Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has gained significant public health attention owing to its devastating effects on lives and livelihoods worldwide. Due to difficult access to vaccines in many developing countries and the inefficiency of vaccines in providing complete protection even with fully vaccinated persons, there remains the need for the development of novel drugs to combat the disease. This study describes the in vitro activity of a library of fifty-five spiro-fused tetrahydroisoquinoline–oxindole hybrids (spirooxindoles) as potential blocking agents of the interaction between the SARS-CoV-2 viral spike and the human angiotensin-converting enzyme 2 (ACE2) receptor, essential for viral transmission. The synthesis was conducted by the Pictet-Spengler condensation of phenethylamine and isatin derivatives, while the screening against spike-ACE2 interaction was done using our previously described AlphaScreen fluorescent assay. The in vitro screening identified compound (11j) as the most active, showing a 50% inhibitory concentration (IC50) of 3.6 μM against SARS-CoV-2 spike/ACE2 interaction. Structure-activity relationships explained via molecular docking studies and the computation of binding free energy of each compound with respect to the spike/ACE2 protein-protein interaction showed that the most active compound possesses a bulky naphthyl group, which addresses voluminous hydrophobic regions of the ACE2 binding site and interacts with the hydrophobic residues of the target. Therefore, these compounds could be potentially useful in searching for SARS-CoV-2 spike/ACE2 interaction blocking agents.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".