Catalogue / LGD-3033
LGD-3033
Also written as Pyrroloquinolinone SARM.
A tetracyclic pyrrolo-quinolinone, structurally unrelated to the aryl propanamides that make up most of this class despite being sold beside them.
| Molecular formula | C16H14ClF3N2O |
| Average mass | 342.74 Da |
| Monoisotopic mass | 342.0747 Da |
| Molecular target | Androgen receptor |
| Electrospray polarity | Positive |
| Class | Androgen receptor modulators |
| Determination | Small molecule analysis, specialist compound |
| Price | 377 USD |
Computed at build time from the composition shown on this page, not transcribed from a supplier datasheet.
LGD-3033 has an average molecular weight of 342.74 daltons and a monoisotopic mass of 342.0747 daltons, computed from the molecular formula C16H14ClF3N2O. Identity is confirmed by matching the measured mass against a certified reference standard, and purity is reported separately by reversed-phase chromatography at the compound's own ultraviolet maximum rather than at the 214 nm used for peptides. Neither figure states which enantiomer is present, which is a third determination on a chiral stationary phase.
| Ion | m/z |
|---|---|
| [M+H]+ | 343.082 |
| [M-H]- | 341.0674 |
Usable response for this compound is in positive mode. The other ion is given because it is the one a wrongly configured method looks for.
A molecule of this size does not produce the multiply charged envelope a peptide does. It produces one singly charged ion, and which polarity that ion appears in is decided by the functional groups rather than by convenience. A nitro or cyano aromatic responds in negative mode; a basic amine responds in positive.
That is why a screen acquired in a single polarity misses part of its own compound list, and why a non-detect from such a screen is not evidence that a substance is absent. The polarity used belongs on the certificate alongside the result.
| One chlorine, so an M plus 2 satellite is present. LGD-4033 has none, which is the fastest way to tell two compounds apart whose names differ by a single digit. |
| The rigid aromatic system absorbs strongly in the ultraviolet, so purity is measured at the maximum of that absorbance rather than at 214 nm, where a peptide method would look and where this compound gives a poor peak-to-noise ratio against the solvent front. |
| The reference standard is not stocked as widely as those for the mainstream compounds, so the determination is quoted on the basis that one is sourced before the sample is booked in, not after. |
Every compound fails in its own way. A generic peptide method applied without regard to these specifics produces a number that looks like a result and is not one.
Non-steroidal small molecules, most of them a single enantiomer of an aryl propanamide. They are not peptides and almost nothing carried over from peptide work applies: there is no amide backbone to detect at 214 nm, the molecules are a fraction of the mass of the smallest peptide in this catalogue, and the impurity that matters most is a mirror image that no achiral column separates from the target.
LC-MS identity against a certified reference standard, acquired in the ionisation polarity the compound actually responds in rather than in whichever polarity the instrument was left in. Purity by HPLC-UV at the compound's own absorbance maximum, not at 214 nm. Enantiomeric purity is a separate determination on a chiral stationary phase and is reported as a separate figure, because an achiral method cannot see it.
Where the delivered milligram figure matters rather than the percentage, assay against a certified reference standard gives content directly, and where no such standard exists quantitative NMR against a certified internal standard gives an absolute purity that needs no standard of the analyte at all.
| LC-MS identity | Measured mass |
| HPLC-UV purity | Area at the UV maximum |
| Enantiomeric purity | Chiral stationary phase |
| Water content | Karl Fischer |
| Elemental impurities | ICP-MS |
| Residual solvents | GC-MS |
What is the molecular weight of LGD-3033?
The average molecular weight is 342.74 daltons and the monoisotopic mass is 342.0747 daltons, computed from the molecular formula C16H14ClF3N2O shown on this page. Both figures are calculated rather than transcribed, so they can be checked against the stated composition.
How is LGD-3033 tested for purity and identity?
LC-MS identity against a certified reference standard, acquired in the ionisation polarity the compound actually responds in rather than in whichever polarity the instrument was left in. Purity by HPLC-UV at the compound's own absorbance maximum, not at 214 nm. Enantiomeric purity is a separate determination on a chiral stationary phase and is reported as a separate figure, because an achiral method cannot see it. Purity is an area ratio measured at the compound's own ultraviolet maximum, and it describes the chromatographable fraction only. It says nothing about which enantiomer is present, because mirror images are not separated by an achiral column.
What goes wrong when LGD-3033 is analysed?
One chlorine, so an M plus 2 satellite is present. LGD-4033 has none, which is the fastest way to tell two compounds apart whose names differ by a single digit.
What does LGD-3033 analysis cost at ANALYTON?
Small molecule analysis, specialist compound is priced at 377 US dollars, covering the determinations described on this page. Content, safety and elemental determinations are ordered alongside and are priced separately on the price list.
Updated 2026-09-01. Masses computed at build, not transcribed.