Chemical composition, total phenolic and flavonoid contents, and in vitro antimicrobial and antioxidant activities of crude extracts from red chilli seeds (Capsicum frutescens L.)

Peer review under responsibility of Taibah University.

Figures & data

Fig. 1 GC–MS chromatogram of the n-hexane extract of the seeds of C. frutescens.

Fig. 2 GC–MS chromatogram of the chloroform extract of the seeds of C. frutescens.

Table 1 Chemical composition of crude extracts of C. frutescens seeds analyzed by GC–MS.

SI no.	Name of compounds	MW	Formula	Retention time	Peak area (%)
n-Hexane crude extract
1	3-Carene	136	C10H16	5.32	14.88
2	Hexadecane	226	C16H34	12.25	2.41
3	Octadecane	254	C18H38	14.34	1.55
4	Eicosane	282	C20H42	16.16	1.25
5	10-Heneicosene	294	C21H42	16.98	0.42
6	Docosane	310	C22H46	17.60	0.93
7	9,12-Octadecadienoic acid, methyl ester	294	C19H34O2	18.10	0.84
8	Hexadecanoic acid	256	C16H32O2	18.52	13.76
9	1-Docosene	308	C22H44	19.92	0.69
10	9,12-Octadecadienal	264	C18H32O	20.97	33.54
11	Heptadec-8-ene-2,4-dione	266	C17H30O2	21.59	7.60
12	Tetracosane	338	C24H50	22.19	8.83
13	2(3H)-Furanone,dihydro-5(2-octenyl)	196	C12H20O2	23.60	6.09
14	Hexadec-8-ene-2,4-dione	252	C16H28O2	25.25	6.05
15	Pentadec-8-ene-2,4-dione	238	C15H26O2	27.51	1.17
Chloroform crude extract
1	1-Phenyloctane	190	C14H22	12.41	2.18
2	Phenol,2,4-bis(1,1-dimethyethyl)	206	C14H22O	13.65	5.48
3	Octadecane	254	C18H38	14.57	3.93
4	1-Hexadecene	224	C16H32	14.71	8.76
5	Eicosane	282	C20H42	16.41	2.96
6	5-Eicosene	280	C20H40	16.54	6.54
7	Hexadecanoic acid, ethyl ester	284	C18H36O2	17.27	3.49
8	Docosane	310	C22H46	17.84	2.37
9	1-Dodecene	168	C12H24	17.91	4.29
10	9-Hexadecenoic acid, methyl ester	268	C17H32O2	18.10	2.13
11	9,12-Octadecadienoic acid, methyl ester	294	C19H34O2	18.14	4.16
12	Palmitic acid	256	C16H32O2	18.39	25.31
13	Linoleic acid	280	C18H32O2	20.40	23.28
14	9,12-Octadecadienoic acid-2-hydoxy-1-(hydroxyl methyl)ethyl ester	354	C21H38O4	20.66	5.15

Table 2 Antimicrobial activity of crude extracts of C. frutescens seeds (inhibition zone in mm, excluding well/disc diameter).

Name of microorganism	n-Hexane extract	Chloroform extract	Positive control
Escherichia coli	10 ± 0.52^a	08 ± 1.32^ac	06 ± 0.34^bc
Salmonella typhi	5 ± 0.81^a	06 ± 0.95^a	18 ± 1.3^b
Proteus vulgaris	5.5 ± 1.0^a	7 ± 0.5^a	16 ± 1.5^b
Pseudomonas aeruginosa	14 ± 1.3^a	13 ± 1.7^ac	10 ± 0.86^bc
Klebsilla pneumonae	12 ± 0.5^a	13 ± 2.0^a	10 ± 2.59^a
Bacillus cereus	10 ± 1.0^a	10 ± 1.8^ac	19 ± 1.5^bd
Staphylococcus aureus	14 ± 0.5^a	15 ± 1.32^ac	8 ± 0.62^bd
Staphylococcus aureus MRSA	5 ± 0.2^a	0	13 ± 0.5^b
Candida albicans	13 ± 1.74^a	20 ± 0.43^b	18 ± 0.90^b
Candida krusei	12 ± 1.03^a	14 ± 1.51^ab	11 ± 0.86^ac
Alternaria alternata	11 ± 0.62^a	0	14 ± 0.45^b
Aspergillus flavus	0	0	15 ± 0.33
Aspergillus niger	16 ± 1.0^a	0	17 ± 0.50^a

Data are expressed as the mean ± standard deviation of three separate experiments (p < 0.05); Different letters in superscript indicate significant differences among different extracts and control according to Tukey HSD test. Positive control for antibacterial activity ciprofloxacin (5 μg/mL) and for antifungal activity nystatin (100 units/disc).

Table 3 Percentage yield, total phenolic content (TPC) and total flavonoid content (TFC) of crude extracts of C. frutescens seeds.

Extract	% Yield	TPC (GAE mg/g) of dry weight of extract	TFC (RU mg/g) of dry weight of extract
n-Hexane	11.2	26.15 ± 0.76	12.84 ± 0.22
Chloroform	5.4	7.95 ± 0.35	4.64 ± 0.54

TPC and TFC values are mean ± standard deviation of three separate experiments (p < 0.05).

Fig. 3 DPPH radical scavenging ability of the crude extracts of C. frutescens seeds.