Crocus cancellatus subsp. damascenus stigmas: chemical profile, and inhibition of α-amylase, α-glucosidase and lipase, key enzymes related to type 2 diabetes and obesity

Figures & data

Table 1. Extraction yield (%) and phytochemicals content of C. cancellatus subsp. damascenus stigmas extract.

	C. cancellatus subsp. damascenus
Extract yield (%)	5.8
Total phenols*	146.8 ± 2.5
Total flavonoids†	57.5 ± 1.2
Total carotenoids‡	93.5 ± 1.6

Data are mean ± SD (n = 3).

*Data are expressed as mg chlorogenic acid equivalents per g extract.

†Data are expressed as mg quercetin equivalents per g extract.

‡Data are expressed as mg β-carotene equivalents per g extract.

Table 2. Main constituents tentatively identified in C. cancellatus subsp. damascenus stigmas extract.

Compound	Rt (min)	Abundance (%)
2-Furancarboxaldehyde, 5-methyl-	7.46	0.8
4H-pyran-4-one-2,3-dihydro-3,5-dihydroxy-6-methyl-	10.37	3.2
2-Furancarboxaldehyde, 5-(hydroxymethyl)-	11.41	29.5
Methyl palmitate	17.44	1.6
Palmitic acid	17.75	1.1
Xanthotoxin	18.54	1.3
Methyl oleate	18.72	10.7
Methyl stearate	18.88	5.5
Osthol	19.15	5.4
Isopimpinellin	19.84	1.1
Methyl arachidate	20.17	0.8

Figure 1. HPTLC chromatograms of C. cancellatus subsp. damascenus extract and standards.

Figure 2. HPTLC chromatograms of C. cancellatus subsp. damascenus extract and standard.

Table 3. Radical scavenging activity, antioxidant property, metal reducing and chelating activity of C. cancellatus subsp. damascenus stigmas extract.

			β-Carotene bleaching test (µg/mL)
C. cancellatus subsp. damascenus	DPPH test (µg/mL)	ABTS test (µg/mL)	30 min	60 min	FRAP test µM Fe(II)/g)	Fe^2+ chelating activity assay
Extract	34.6 ± 1.6**	21.6 ± 2.3**	104.5 ± 3.8**	41.0 ± 1.3**	53.9 ± 2.1**	24.6 ± 2.2**
Ascorbic acid	5.0 ± 0.8	1.7 ± 0.3
Propyl gallate			1.0 ± 0.041	1.0 ± 0.034
BHT					63.2 ± 4.3
EDTA						1.27 ± 0.05

Data are expressed as mean ± S.D. (n = 3); DPPH radical scavenging activity assay; antioxidant capacity determined by radical cation (ABTS⁺); ferric reducing antioxidant power (FRAP). Ascorbic acid was used as positive control in ABTS and DPPH test; propyl gallate was used as positive control in β-carotene bleaching test BHT was used as positive control in FRAP test; EDTA was used as positive control in Fe²⁺ chelating activity assay. Differences within and between groups were evaluated by one-way analysis of variance test ***p < 0.0001 followed by a multicomparison Dunnett’s test: **p < 0.01 compared with the positive controls.

Figure 3. Concentration–response curve of C. cancellatus subsp. damascenus against α-glucosidase and α-amylase enzymes. Data are mean ± SD (n = 3).