PMC

(a) Sodium nitrite, acetic acid to form 2, (b) thionyl chloride, Δ to form 3, (c) acetaldehyde, Δ to form 4, (d) 2-pyridine carboxaldehyde, tosic acid, Δ to form 5, (e) 3-pyridine carboxaldehyde, Δ to form 6, (f) 2-pyridinium carboxaldehyde iodide, Δ to form 7, (g) 4-pyridinium carboxaldehyde iodide, Δ to form 8, (h) 3-pyridinium carboxaldehyde, Δ to form 9. The solubility data for these compounds is presented in Table S2.

GC/MS chromatogram of safranal aqueous extract. (1) Acetic acid (4,99%); (2) 3,5,5-trimethyl-3-ciclohexen-2-ona (1,10%); (3) 3,7-dimethyl-1,6-octadien-3-ol (linalol) (6,68%); (4) 2,6,6-trimethyl-1,4-ciclohexadien-1- carboxaldehyde (4,35%); (5) 3,5,5-trimethyl-3-ciclohexen-1-ona (1,94%); (6) 2,6,6-trimethyl-1-cyclohexene-1-carboxaldehyde (8,38%); (7) 2,6,6- trimethyl-1,3-ciclohexadien-1- carboxaldehyde (safranal) (72,56%)

Partial pyrolysis–gas chromatography/mass spectrometry chromatograms of (a) pure chitin and (b) cockroach cuticle. 1, Pyridine; 2, methyl pyridine; 3, acetamide; 4, 3-hydroxy-2-pyridone; 5, 2-pyridine carboxaldehyde; 6, acetylpyrrole; 7, acetylpyrroline; 8, amine derivative; 9, levoglucosenone; 10, unknown; 11, acetyldihydropyridine; 12, acetylpyridone; 13, 3-acetamidofuran; 14, 3-acetamido-5-methylfuran; 15, 3-acetamido-4-pyrone; 16, oxazoline structures; Pr₁, methyl pyrrole; Pr₂, phenol; Pr₃, unknown; Pr₄, indole; Pr₅, methylindole; Pr₆, diketopiperazines; CnFA, fatty acyl moieties, where n refers to the carbon chain length and n: 1 denotes mono-unsaturation in the alkyl chain. No n-alkanes/alkenes were detected. The analysis time was 55 min.