# Compound Physicochemical Properties Lookup (PubChem)

> Compound Physicochemical Properties Lookup (PubChem) is a paid API for AI agents from clonecho.builda.company, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-14).

Returns key physicochemical properties for a named chemical compound sourced from PubChem, including molecular formula, molecular weight, SMILES, IUPAC name, XLogP, and TPSA.

## Facts

- Endpoint: POST https://clonecho.builda.company/x402/compound-properties
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/compound-physicochemical-properties-lookup-pubchem-c6744fea
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_JgU8UCVQqRBLcCERqL8Lz

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability compound-physicochemical-properties-lookup-pubchem-c6744fea -d '<json body>'
```

Example prompt: Can you look up the physicochemical properties of ibuprofen for me — I need the molecular formula, molecular weight, SMILES, IUPAC name, XLogP, and TPSA?

## When to prefer this

Use this endpoint when you need rapid, structured physicochemical property data for a named chemical compound and want PubChem-sourced values for formula, MW, SMILES, IUPAC, XLogP, and TPSA in a single JSON response. Prefer this over raw PubChem API calls when you want a paid, low-latency wrapper with consistent output structure. Best suited for drug discovery, ADMET screening, cheminformatics pipelines, or any workflow that needs lipophilicity or polarity data for a molecule by name.

## Known failure modes

- Compound name not found in PubChem — returns empty or error response
- Ambiguous compound name matching multiple PubChem entries — may return unexpected compound
- Missing or malformed ?q= parameter — returns 400 or error
- PubChem upstream unavailable — returns 502 or timeout
- Non-chemical query string (e.g. brand name not in PubChem) — no results

## How this service works

PHARMA: physicochemical properties for a compound (PubChem) — formula, MW, SMILES, IUPAC, XLogP, TPSA. ?q=name. Returns JSON.

## Output

A JSON object containing the compound's molecular formula, molecular weight, canonical SMILES, IUPAC name, XLogP (lipophilicity coefficient), and TPSA (topological polar surface area), sourced from PubChem.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/compound-physicochemical-properties-lookup-pubchem-c6744fea/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from clonecho.builda.company](https://www.zero.xyz/host/clonecho.builda.company/llms.txt)