Drug Evolution: p-Aminobenzoic Acid as a Building Block
Bibliographic record
Abstract
The core or the building block is an important component in drug development. In this article, we propose and review p-aminobenzoic acid (PABA) as a building block used in the design of drugs or drug candidates. PABA is frequently found as a structure moiety in drugs. For example, in a database of 12,111 commercial drugs, 1.5% (184 drugs) were found to contain the PABA moiety. These drugs have a wide range of therapeutic uses, such as: sun-screening, antibacterial, antineoplastic, local anesthetic, anticonvulsant, anti-arrhythmic, anti-emetic, gastrokinetic, antipsychotic, neuroleptic, and migraine prophylactic. This article reviews the molecular targets and the mechanisms of these activities. Drugs containing PABA also show a wide range of structural diversity. Of the 184 PABA containing drugs identified, 95 different substitutions were found at the carboxylic group and 61 were found at the amino group of the building block. Substitution on the aromatic ring was also diverse. 13, 3, and 13 different side chains were found to modify positions 2, 3 and 5 of the aromatic ring respectively. In some drugs, the amino group is further substituted to form tertiary amine (4 different side chains). Substitutions at the carboxyl and amino groups of PABA are particularly suitable for the generation of combinatorial libraries. Just by reshuffling the identified side chains of the 184 PABA containing drugs, 4.5 million compounds can be generated. Consequently, PABA fits well as a building block for a general chemical library of "drug-like" molecules with a wide range of functional and structural diversity.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.002 |
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".