AssayIndex
Cross-section

MOTS-c impurity profile

Every named species the index has reported alongside MOTS-c, how often, at what level, and what its presence implies about the synthesis or the handling. Reporting threshold is 0.05 % area; anything below it is invisible to this page and is silently added to the main peak.

105 recordsmedian 99.13 %spec 98.0 %
Median total impurities 0.87% n=105
Median largest single 0.41% n=105
Worst single observed 1.83% n=105
Named species observed 4 / 4 n=4
Named speciesΔRT (min)Δ mass (Da)Seen inMedian % areaMax % area
Met1 sulfoxide (+16 Da)-0.38+15.99597%0.191.83
des-Met1 (−131 Da)+0.22-131.04092%0.130.81
deamidated (+1 Da)-0.30+0.98490%0.141.57
bis-sulfoxide (+32 Da)-0.66+31.99089%0.341.44

Met1 sulfoxide (+16 Da)

Retention offset from the main peak
-0.38 min on RG-2
Mass difference
+15.995 Da
Reported in
102 of 105 records (97 %)
Level when reported
median 0.19 %, max 1.83 %
How it separates
Baseline-resolved on the reference method.

des-Met1 (−131 Da)

Retention offset from the main peak
+0.22 min on RG-2
Mass difference
-131.040 Da
Reported in
97 of 105 records (92 %)
Level when reported
median 0.13 %, max 0.81 %
How it separates
Close-eluting on the reference method, and merged with the main peak on a short gradient. The index prints the resolution figure for such a pair and applies no criterion to it — where the two are not separated, what matters is that the integration convention is stated.

deamidated (+1 Da)

Retention offset from the main peak
-0.30 min on RG-2
Mass difference
+0.984 Da
Reported in
95 of 105 records (90 %)
Level when reported
median 0.14 %, max 1.57 %
How it separates
Baseline-resolved on the reference method.

bis-sulfoxide (+32 Da)

Retention offset from the main peak
-0.66 min on RG-2
Mass difference
+31.990 Da
Reported in
93 of 105 records (89 %)
Level when reported
median 0.34 %, max 1.44 %
How it separates
Baseline-resolved on the reference method.

Degradation pathways

Degradants are a handling finding rather than a synthesis finding. A lot that shipped clean and arrived oxidised tells you about the courier, not the chemist.

  • double methionine oxidation — MOTS-c carries two Met residues and both oxidise
  • N-terminal Met excision during expression-derived production