An Investigation of Fastness and Potential Antibacterial Features on Cotton Fabric Colored with Novel Azo Compounds

Abstract

Novel azo compounds were synthesized by diazotization of aniline and of 3-aminopyridine in the presence of NaNO₂ and HCl, followed by coupling with 2-methylresorcinol in alkaline media. The structures were characterized using FT-IR, ¹H NMR, and ¹³C NMR analysis. The main purpose of the present study is to investigate coloration applications, and antibacterial and fastness properties of the new azo structures in textile industry. Exhaust dyeing processes were applied on cotton fabric. Color strength (K/S values), L, a*, and b* values were measured. The color fastness values (to rubbing, light, perspiration, washing) of azo compounds on cotton fabric were presented according to ISO standards for comparison. Antibacterial activity assessment of the colored fabrics was performed according to AATCC 147-2016 test method against two types of bacteria: Staphylococcus aureus and Klebsiella pneumoniae. The fabric dyed with 2-methyl-4-[pyridin-3-yldiazenyl]benzene-1,3-diol demonstrated acceptable antibacterial activity against S. aureus.

Keywords

Azo Compound Cotton Dyeing Fastness

Introduction

Azo compounds constitute the largest chemical class of commercial synthetic organic colorants, comprising approximately 70% of all dyes used in industry.^1,2 They can possess an especially intense yellow, red, orange color, even a blue or green color depending on the exact structure of the molecule. As a result of providing bright color at low cost, azo compounds have great importance as dyes and also pigments for coloring of different materials in various fields such as printing inks, paints (architectural, automotive, and artists’), plastics, rubber, crayons, and colored chalks, particularly in the textile, cosmetic, and pharmaceutical industries. Azo compounds are substantial in almost whole industrial application classes of textile dyes such as acid, reactive, direct, metal complex, disperse, vat, sulfur, basic, and solvent dyes.^3–6

Azo colorants include as their common structural chromophore feature the azo (-N==N-) linkage and can be classified according to the number of azo groups in the same structure such as monoazo (commercially mostly used), disazo, trisazo, polyazo, and azoic.^1,7 Industrial azo compounds occur by the same two reaction steps: diazotization of a primary aromatic amine followed by coupling with electron-rich nucleophiles such as mostly used amino and hydroxyl groups.^1,2,7,8 Lots of derivatives with different side groups having different features can be synthesized by this method. This versatility gives rise to many different application fields such as photoreaction sensitizers, advanced applications in organic synthesis, extraction of metal ions, acid–base indicators, liquid crystalline displays, electro-optical devices, and biological–medical studies.^9–12

Azo compounds can exhibit a great variety of interesting biological activities, including antimicrobial, anti-inflammatory, anthelminthic, antiviral, antioxidant, antidiabetic, antitubercular, anticonvulsant, and anticancer effects. The medical importance of these compounds is well known for their antibiotic, antifungal, and anti-HIV properties.^12–24

The majority of azo pigments are safe to use, but some of them are, especially those derived from aniline, toluidine, and benzidine diazo components, mutagenic and carcinogenic. They can undergo natural anaerobic degradation, so break down and release potentially harmful amines for humans and the entire ecosystem.^9,25,26 A list of EU-restricted aromatic amines is given in the literature.²⁷ Replacement of aromatic diazo components with heteroaromatic ones could satisfy toxicological requirements for the design of new dyes.²⁸

This study is centered on synthesizing novel azo compounds and then investigating their color fastness and antibacterial properties on cotton fabric.

Experimental

Materials

All used reagents and solvents were of analytical grade quality. Indosol E 50 Liq. was obtained from Clariant Chemicals and used as a cationic agent. The bleached, hydrophilic 100% cotton fabric was in a single jersey knit structure (İzmir Basma Factory, Turkey), 150 g/m².

Synthesis of the Azo Compounds

The synthetic route of the novel azo compounds can be seen in Scheme 1. All compounds were synthesized by the azo coupling reaction of aniline and 3-amino pyridine with 2-methyl resorcinol.

Scheme 1.

Synthetic route of azo compounds 1 and 2.

2-Methyl-4-[phenyldiazenyl]benzene-1,3-diol (Compound 1)

Aniline (1000 mg, 10.73 mmol) was dissolved in pure water (50 mL) and HCl (10 mL, 30%). Then, the solution of equivalent sodium nitrite (NaNO₂) was added dropwise to this solution. The temperature was kept between 0 and 5°C during addition. Equivalent 2-methyl resorcinol (1332 mg, 10.73 mmol) in NaOH solution (70 mL, 10%) was added into this diazonium solution with efficient stirring. Then dilute HCl solution was added to the mixture until it became neutral. The formed solid material was filtered off. Finally, pure product was obtained by recrystallization from ethanol. Yield: 2100 mg (85%); m.p. 130°C–131°C.

This compound is soluble in ethanol and dimethyl sulfoxide. FTIRν_max/cm⁻¹ 3150, 2918, 2850, 1625, 1530, 1488 (N=N), 1430, 1341, 1307, 1235, 1183, 1134, 1084, 1035, 901, 794, 752, 682. ¹H NMR (DMSO-d₆) δ, ppm: 13.23 (1H, s, OH), 10.53 (1H, s, OH), 7.84–7.82 (2H, d, ArCH), 7.56–7.51 (3H, m, ArCH), 7.46–7.43 (1H, d, ArCH), 6.61–6.59 (1H, d, ArCH), 2.14 (3H, s, CH₃). ¹³C NMR (DMSO-d₆) δ, ppm: 161.25, 154.47, 150.61, 132.20, 130.50, 129.91, 129.83, 121.89, 111.19, 108.80, 8.21.

2-Methyl-4-[pyridin-3-yldiazenyl]benzene-1,3-diol (Compound 2)

3-Amino pyridine (1000 mg, 10.62 mmol) was dissolved in pure water (50 mL) and HCl (10 mL, 30%). Then, the solution of equivalent sodium nitrite (NaNO₂) was added dropwise into this solution. The temperature was kept between 0°C and 5°C during addition. Equivalent 2-methyl resorcinol (1319 mg, 10.62 mmol) in NaOH solution (70 mL, %10) was added to this diazonium solution with efficient stirring. Then, dilute HCl solution was added into the mixture until it became neutral. The formed solid material was filtered off. Finally, pure product was obtained by recrystallization from ethanol. Yield: 2150 mg (88%); m.p. 224°C–225°C.

This compound is soluble in ethanol and dimethyl sulfoxide. FTIRν_max/cm⁻¹ 3071, 2988, 2590, 1613, 1451, 1421 (N=N), 1357, 1328, 1261, 1194, 1178, 1089, 806, 793, 806, 757, 697. ¹H NMR (DMSO-d₆) δ, ppm: 12.53 (1H, s, OH), 10.63 (1H, s, OH), 9.06-9.05 (1H, d, ArCH), 8.61-8.60 (H, d, ArCH), 8.22-8.20 (1H, d, ArCH), 7.57-7.53 (2H, m, ArCH), 6.61-6.59 (2H, d, ArCH), 2.02 (3H, s, CH₃). ¹³C NMR (DMSO-d₆) δ, ppm: 161.95, 154.93, 150.92, 146.74, 145.70, 132.82, 127.92, 126.89, 124.89, 111.26, 109.00, 8.28.

Cationization and Dyeing Procedures

Cotton specimens were cationized with the assistance of a cationic auxiliary (Indosol E 50 Liq, 5% conc.) at 60°C for 20 min in acidic media (via acetic acid, pH 5) by using the exhaustion method (1:10 liquor ratio). The cotton fabrics were then rinsed with tap water and air-dried.

After cationization process, the cotton fabrics were dyed according to the recipes given in Table 1. Exhaust dyeing processes were carried out at different conditions according to Figure 1.

Table 1.

Properties of dyeing recipes.

Recipe no.	Compound type	Dye concentration (%)	Temperature	Liquor ratio
1	Compound 1	1	60	1:10
2	Compound 1	1	80	1:10
3	Compound 1	1	80	1:20
4	Compound 1	3	60	1:10
5	Compound 1	3	80	1:10
6	Compound 2	1	60	1:10
7	Compound 2	1	80	1:10
8	Compound 2	1	80	1:20
9	Compound 2	3	60	1:10
10	Compound 2	3	80	1:10

Figure 1.

Dyeing process conditions.

The azo compounds 1 and 2 were solubilized in alkali media (via sodium hydroxide (48 Be°), pH 10) for 10 min at the specified dyeing temperature in the recipes and then applied to cationic cotton fabrics for the specified dye concentrations during 45 min. Then, the dyed specimens were sequentially neutralized with acetic acid, washed with water thoroughly, and air-dried for further testing.

Characterization Analyses

FT-IR spectra were recorded by Perkin-Elmer Spectrum 100 Infrared Spectrometer. ¹H NMR and ¹³C NMR studies were performed by Agilent 400 FT-NMR. Dyeing and cationization processes were carried out in Termal Laboratory Dyeing Machine (Turkey).

Color Measurements

The color strength (K/S), L, a, and b values of the dyed samples were determined using EasyMatch QC software on a Hunterlab Ultrascan Pro VIS color spectrophotometer attached to a personal computer. The color strength (K/S) of the sample was calculated using the Kubelka–Munk equation (equation (1))

K / S = {(1 - R)}^{2} / 2 R

(1)

where R is the reflectance, K is the absorbance, and S is the scattering coefficient.

Antibacterial and Fastness Test Methods

Antibacterial properties of the fabrics, colored with recipes 4 and 9, were evaluated according to AATCC 147-2016 test method against two types of bacteria: Staphylococcus aureus and Klebsiella pneumoniae.

Fabrics were tested according to ISO 105-X12 for crock fastness, ISO 105-B02 for lightfastness, ISO 105-CO6 for washfastness, and ISO 105-E04 for perspiration fastness.

Results and Discussion

Synthesis and Characterization

The synthetic route of azo compounds can be seen in Scheme 1. All compounds were synthesized by the azo coupling reaction of aniline and 3-amino pyridine with 2-methyl resorcinol. Newly synthesized azo compounds were characterized by FT-IR, ¹H NMR, and ¹³C NMR techniques.

Compound 1 exhibited the broad OH band at 3150 cm⁻¹ in the FT-IR spectrum (Figure 2). The formation of compound 1 was clearly indicated by the appearance of two OH peaks at 13.23 and 10.53 ppm, aromatic peaks at 7.84–6.59 ppm, and an aliphatic CH₃ peak at 2.01 ppm in its ¹H NMR spectrum. The singlet peak at 13.23 ppm can be assigned to the proton of the OH group which is intramolecular hydrogen bonded with the nitrogen atom in the neighboring azo group (Scheme 2).^29–32 The ¹³C NMR spectrum of compound 1 is compatible with the suggested structure (Figure 3).

Figure 2.

¹H NMR spectrum of compound 1.

Scheme 2.

Hydrogen bonding at compounds 1 and 2.

Figure 3.

¹³C NMR spectrum of compound 1.

The compound 2 signified the broad OH band in the FT-IR spectrum (Figure 4). The formation of compound 2 was clearly indicated by the appearance of two OH peaks at 12.53 and 10.63 ppm, aromatic peaks at 9.06–6.59 ppm, and an aliphatic CH₃ peak at 2.02 ppm in its ¹H NMR spectrum. The singlet peak at 12.53 ppm can be assigned to proton of OH group which is intramolecular hydrogen bonded with the nitrogen atom in the neighboring azo group (Scheme 2). The ¹³C NMR spectrum of compound 2 shows the presence of expected carbon atoms (Figure 5).

Figure 4.

¹H NMR spectrum of compound 2.

Figure 5.

¹³C NMR spectrum of compound 2.

Dyeing

Synthesized azo compounds are pigment forms and not soluble in water, but they are soluble in NaOH. In the exhaust dyeing process, first, the solubilization step in alkali media is needed (during 10 min, pH 10). Azo compounds (1, 2) become anionic in character in basic media by giving H⁺ ions to the medium. For more electrostatic interactions between the dye and the cotton at the main dyeing step (during 45 min), the cotton fabric was processed with cationic agent prior to the dye application. It is thought that their application methods are similar to those for direct dyes.

Colorfastness Assessments

The color fastness values of the fabrics dyed with the azo compounds 1 and 2 are given in Tables 2 –4 and Figures 6 and 7. The color fastness properties, except for light fastness, were measured on a scale of 1–5 (very poor, poor, fair, good, and very good). The dry rubbing fastness values of the fabrics dyed with compound 2 were highly commercially acceptable (grade 4–5, 5). The rubbing fastness (dry and wet) and washing fastness values of the fabric dyed with compound 2 were generally better than that of the fabric dyed with compound 1 (according to Figures 6 and 7, Table 2). The washing fastness results of the dyed fabrics were mostly moderate level (≥2–3 grade). When comparing the perspiration fastness values of the fabric samples treated with recipe numbers 4, 9, 5, and 10 (for 3% dye concentration with a 1:10 liquor ratio at 60°C and 80°C), the results for compound 2 were slightly higher than those for compound 1 (Table 3). The reason for the better fastness values of compound 2 could be the presence of nitrogen atoms in the benzene structure, unlike compound 1 (Scheme 1). This difference can ensure a more anionic character for compound 2 in an alkali dyeing bath and so better bonding can be achieved by more electrostatic interactions between the dye and cationic fabrics. The lightfastness is rated between 1 and 8 (very poor to outstanding) on wool (blue) scale. The light fastness values of compounds 1 and 2 were poor, being level with grade 2 (Table 4).

Table 2.

Washing fastness values of the dyed fabrics.

Color fastness to domestic and commercial launderingRecipe number	Color change	Staining
	Color change	Acetate	Cotton	Nylon	Polyester	Acrylic	Wool
1	3	2–3	3	2–3	4–5	4–5	3
2	3	2–3	3	2–3	4–5	4–5	3
3	3	2–3	3	2–3	4–5	4–5	3
4	3	1	2	1	3–4	4	2
5	3	1	2	1	4	4–5	2
6	3	3	3	3	5	5	4
7	3	3	3	3	5	5	4–5
8	3	3–4	3	3	5	5	4–5
9	3–4	3–4	3	3–4	5	5	4–5
10	3–4	3–4	3	3	5	5	4–5

Table 3.

Perspiration fastness values of the dyed fabrics.

Color fastness to perspirationRecipe number		Color change	Staining
Color fastness to perspirationRecipe number		Color change	Acetate	Cotton	Nylon	Polyester	Acrylic	Wool
1	Acidic	3	2–3	3	2	3	4	2
1	Alkaline	3	2	3	1–2	3	4	2
2	Acidic	4	3	4	2–3	3–4	4-5	2–3
2	Alkaline	4	3	4	2–3	3–4	4-5	2–3
3	Acidic	3–4	2–3	3–4	2	3	4	2
3	Alkaline	3–4	2	3–4	1–2	3	4	2
4	Acidic	2	1–2	2	1	2–3	2–3	1
4	Alkaline	2	1	2	1	2–3	2–3	1
5	Acidic	2–3	1–2	2–3	1	2–3	3	1–2
5	Alkaline	2–3	1–2	2–3	1	2–3	3	1–2
6	Acidic	3	3	3	2	3	4	2
6	Alkaline	3–4	3	3–4	1–2	3	4-5	2–3
7	Acidic	3	2–3	3	1–2	3	4	2
7	Alkaline	3	3	3	2	4	4	2–3
8	Acidic	3	2	3	1	3–4	4	2
8	Alkaline	2	2	2	1	3–4	4	2
9	Acidic	3	2–3	3	1–2	3–4	4	3
9	Alkaline	3	2–3	3	2	4	4	3
10	Acidic	3	2	3	1–2	3–4	4	3
10	Alkaline	3	2–3	3	2	4	4	3

Table 4.

Light fastness values of compounds 1 and 2 on the dyed fabrics which treated with recipe numbers 4 and 9.

Dyed with compound 1(recipe number 4)2

Dyed with compound 2(recipe number 9)2

Figure 6.

Comparison of dry rubbing fastness results of the cotton fabrics dyed with compounds 1 and 2.

Figure 7.

Comparison of wet rubbing fastness results of the dyed fabrics colored with compounds 1 and 2.

Color Strength

The results of the spectrophotometric measurements of the dyed fabrics are shown in Table 5. The dyed cotton samples exhibited uniformly different shades of orange color. The absorption maximum of compounds 1 and 2 on dyed fabrics (λ_max) was found to be 370 nm. The fabrics dyed with compound 1 had a yellower color shade than the fabrics dyed with compound 2. Color shades changed with the change in the extent of delocalization of electrons depending on the dye structure. The presence of nitrogen atom in compound 2, the only difference between the compound 1 and 2 structures, may cause more delocalization and bathochromic shift. Bathochromic shifts make the light absorbed redder.

Table 5.

K/S, L, a*, and b* values of the dyed fabrics (illuminant D65-10).

	Recipe number(dye %, °C, liquor ratio)	λ_max (nm)	K/S	L	a*	b*
Compound 1	1 (1%, 60°C, 1:10)	370	4.166	78.85	5.88	44.96
	2 (1%, 80°C, 1:10)	370	2.142	78.70	6.00	37.06
	3 (1%, 80°C, 1:20)	370	3.507	77.68	6.50	43.32
	4 (3%, 60°C, 1:10)	370	16.304	65.08	12.17	57.25
	5 (3%, 80°C, 1:10)	370	13.348	66.13	10.23	54.39
Compound 2	6 (1%, 60°C, 1:10)	370	3.560	73.58	8.55	42.01
	7 (1%, 80°C, 1:10)	370	3.361	73.46	8.49	42.88
	8 (1%, 80°C, 1:20)	370	8.727	65.63	9.70	44.93
	9 (3%, 60°C, 1:10)	370	4.577	69.30	9.01	40.78
	10 (3%, 80°C, 1:10)	370	5.885	66.60	9.93	42.15

The a* (+) values, as shown in Table 5, indicate that all samples have a redder tone. The b* (+) values show that the samples are yellower. The L* values indicate that the samples have lighter shades (L value ranges between black = 0 and white = 100) ranging from 65 to 78.

The K/S values of the fabrics dyed with compound 1 were higher than those of the fabrics dyed with compound 2 for 3% dye concentrations (Table 5). The K/S values of the fabrics dyed with compounds 1 and 2 increased with the increase in dye concentrations from 1 to 3% (Figures 8 and 9) and with the increase in liquor ratio from 1:10 to 1:20 (Figure 10). The amounts of the increase in K/S values of compound 1 were higher than those of compound 2 when dyeing at the same temperature and the same liquor ratio, considering the 1 and 3% concentration change, in Figures 8 and 9. The structural difference between compounds 1 and 2 is due to the presence of nitrogen atom in the benzene structure (Scheme 1), which causes change in the extent of delocalization of electrons, thereby causing change in the absorption coefficient (absorbance) of the dyestuff.

Figure 8.

Concentration of dye solution versus K/S values data for the fabrics dyed with recipe numbers 1, 4, 6, and 9.

Figure 9.

Concentration of dye solution versus K/S values data for the fabrics dyed with recipe numbers 2, 5, 7, and 10.

Figure 10.

K/S values of the fabrics dyed with recipe numbers 2, 3, 7, and 9 including various liquor ratios in dyeing baths such as 1:10 and 1:20 for 1% dye concentration, at 80°C.

Antibacterial Activity Assessments

The antibacterial activity of the dyed cotton fabrics was tested according to Antimicrobial Activity Assessment of Textile Materials: Parallel Streak Method (AATCC 147-2016) against S. aureus and K. pneumoniae. The objective of this qualitative method is to determine the antibacterial activity of diffusible antimicrobial agents on treated textile materials and to detect the bacteriostatic activity on textile materials. The average width of a zone of inhibition along a streak on either side of the test specimen may be determined using the following equation (equation (2)):³³

W = (T - D) / 2

(2)

where W is the width of clear zone of inhibition in mm; T is the total diameter of the test specimen and clear zone in mm; and D is the diameter of the test specimen in mm.

S. aureus is both a commensal Gram-positive bacterium and a human pathogen that can lead to numerous infections, including impetigo, scalded skin syndrome, folliculitis, furuncle, carbuncle, osteomyelitis, septic arthritis, endocarditis, toxic shock syndrome, pneumonia, thrombophlebitis, deep tissue abscess, and infection.^34,35

K. pneumoniae is described as a Gram-negative, encapsulate, and non-motile bacterium that can lead to different types of healthcare-associated infections such as pneumonia, bacteremia or septicemia, endocarditis, meningitis, cellulitis, soft tissue infections, and urinary tract infections.^36,37

Antibacterial properties of the fabric samples treated with recipe numbers 4 and 9 (for 3% dye concentration with 1:10 liquor ratio at 60°C) are given in Table 6. Whereas the fabric dyed with compound 2 demonstrated acceptable antibacterial activity against S. aureus (Figure 11), compound 1 was not effective on S. aureus or K. pneumoniae on cotton fabric.

Table 6.

Antibacterial activities of the compounds (1, 2) on the dyed fabrics which treated with recipe numbers 4 and 9.

	S. aureus		K. pneumoniae
The fabric samples	Zone of inhibition	The presence of propagation on the contact surface	Zone of inhibition	The presence of propagation on the contact surface
Dyed with compound 1(recipe number 4)	Not seen	Seen	Not seen	Seen
Dyed with compound 2(recipe number 9)	Seen (mean 7 mm)	Not seen	Not seen	Seen

Figure 11.

Agar plate images of the (a) untreated and (b) treated cotton fabric samples subjected to the parallel streak test (AATCC 147 Test Method) against S. aureus (for compound 2).

Conclusion

The potential use of novel azo compounds synthesized by the azo coupling reaction of aniline and 3-amino pyridine with 2-methyl resorcinol, respectively, as an antibacterial dyestuff in textile coloration was investigated. Antibacterial protection on textile material can be gained via only coloration without any additional finishing process. The color fastness features and antibacterial activities on the cotton fabric were studied. The fabric dyed with compound 2 demonstrated acceptable antibacterial activity against S. aureus. Despite poor/moderate washing fastness and perspiration fastness, crock fastness values were at commercially acceptable levels. The CIELab and K/S values of the fabrics dyed with compounds 1 and 2 were presented for comparison. The dyed fabrics which are shades of orange color have promise for use in antibacterial technical textile production in a variety of fields such as military, healthcare, work/uniforms, domestic products, and sports apparel, especially in medical textiles.

In addition to coloration ability, other possible properties/uses of new azo compounds such as photo reaction sensitizers, acid–base indicators, electro-optical devices, and biological-medical studies might be worthwhile to study.

Footnotes

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

References

Christie

RM.

Chapter 3: Azo dyes and pigments. In: Christie

(ed.) Colour chemistry. Cambridge: The Royal Society of Chemistry, 2001, pp. 45–68.

Benkhaya

M’rabet

El Harfi

Classifications, properties, recent synthesis and applications of azo dyes. Heliyon 2020; 6(1): e03271.

Dardeer

El-sisi

Emam

, et al. Synthesis, application of a novel azo dye and its inclusion complex with beta-cyclodextrin onto polyester fabric. Int J Text Sci 2017; 6(3): 79–87.

Berrie

Lomax

SQ.

Azo pigments: Their history, synthesis, properties, and use in artists’ materials. Stud Hist Art 1997; 57: 8–53 (Monograph series II, conservation research 1996/1997, Washington, DC: National Gallery of Art).

El-Kashouti

Elgemeie

El-Molla

, et al. Synthesis and application of some new disperse azo dyes derived from 2-cyanomethyl benzothiazole. Pigment Resin Technol 2007; 36(6): 382–391.

Benkhaya

El Harfi

Classifications, properties and applications of textile dyes: A review. Appl J Environ Eng Sci 2017; 3(3): 311–320.

Hunger

Gregory

Miederer

, et al. Chapter 2: Important chemical chromophores of dye classes. In: Hunger

(ed.) Industrial dyes, chemistry, properties, applications. New York: Wiley-VCH, 2003, pp. 13–112.

Fleischmann

Lievenbrück

Ritter

Polymers and dyes: Developments and applications. Polymers 2015; 7: 717–746.

Rabbi

Mahasin Ali

Roy

, et al. Preparation of azo dye from Acacia catechu and its application on silk fabrics. Int J Adv Chem Sci Appl 2018; 6(1): 1–4.

10.

Yıldız

Boztepe

Synthesis of novel acidic mono azo dyes and an investigation of their use in the textile industry. Turk J Chem 2002; 26: 897–903.

11.

Kılınçarslan

Erdem

Kocaokutgen

Synthesis and spectral characterization of some new azo dyes and their metal complexes. Transit Metal Chem 2007; 32: 102–106.

12.

Addnan

Synthesis and characterization of new azo dye (1-(4-sulfonyl phenyl azo)-2-(7-chloro-4-[{4-(diethyl amino)-1-methyl butyl}amino]quindine from chloroquine diphosphate and study antibacterial activity. Basrah J Vet Res 2016; 15(1): 271–277.

13.

Di Martino

Sessa

Di Matteo

, et al. Azobenzene as antimicrobial molecules. Molecules 2022; 27(17): 5643.

14.

Mezgebe

Mulugeta

Synthesis and pharmacological activities of azo dye derivatives incorporating heterocyclic scaffolds: A review. RSC Adv 2022; 12: 25932–25946.

15.

Adu

Amengor

CDK

Mohammed Ibrahim

, et al. Synthesis and in vitro antimicrobial and anthelminthic evaluation of naphtholic and phenolic azo dyes. J Trop Med 2020; 2020: 4850492.

16.

Al-Atbi

Al-Salami

Al-Assadi

IJ.

New azo-azomethine derivative of sulfanilamide: Synthesis, characterization, spectroscopic, antimicrobial and antioxidant activity study. IOP Conf Ser J Phys Conf Ser 2019; 1294: 052033.

17.

Węglarz-Tomczak

Górecki

Ł.

Azo dyes—Biological activity and synthetic strategy. Chem Sci Tech Mark 2012; 66(12): 1298–1307.

18.

Gaffer

HE.

Antimicrobial sulphonamide azo dyes. Color Technol 2019; 135(6): 484–500.

19.

Patel

PS.

Synthesis, characterization, and antimicrobial activity of heterocyclic azo dye derivatives. World Sci News 2018; 95: 265–272.

20.

Ali

Abdulredha

Hussain

, et al. Synthesis and biological activity of three novel azo dyes. J Nat Sci Res 2018; 8(18): 1–6.

21.

Kofie

Dzidzoramengor

Adosraku

RK.

Synthesis and evaluation of antimicrobial properties of azo dyes. Int J Pharm Pharm Sci 2014; 7(4): 398–401.

22.

Raghavendra

Kumar

KA.

Synthesis of some novel azo dyes and their dyeing, redox and antifungal properties. Int J ChemTech Res 2013; 5(4): 1756–1760.

23.

Özdemir Saral

Kantar Kaya

Özgüney

, et al. A new water-soluble zinc azaphthalocyanine containing azo groups: Synthesis, characterization, fastness and antibacterial properties on cotton fabric. Tekst Konfeksiyon 2023; 33(2): 169–175.

24.

Özdemir Saral

Özgüney

Kaya Kantar

, et al. An investigation of fastness and antibacterial properties of cotton fabric coloured with water-soluble zinc phthalocyanine containing azo groups. Tekst Konfeksiyon 2016; 26(1): 92–99.

25.

Sarkar

Banerjee

Halder

, et al. Degradation of synthetic azo dyes of textile industry: A sustainable approach using microbial enzymes. Water Conserv Sci Eng 2017; 2: 121–131.

26.

Kareem

Thejeel

Ismael

HI.

Review, analyses of azo dyes’ synthesis, characterization and biological activity. Tex J Multidiscip Stud 2022; 12: 14–20.

27.

Imtiazuddin

Tiki

Textile azo dyes; significance, ecological, health, and safety issues. Pak J Chem 2020; 10(1–4): 35–38.

28.

Meštrović

Racané

Sutlović

, et al. Synthesis and dyeing properties of new azo dyes. In: 12th AUTEX world textile conference, 13–15 June 2012, Zadar, pp. 767–770.

29.

Kantar

Mert

Sasmaz

Microwave-assisted synthesis and characterization of phthalocyanines substituted with azo compound containing eugenol moiety. J Organomet Chem 2011; 696(18): 3006–3010.

30.

Kantar

Baltas

Karaoğlu

ŞA

, et al. Some azo dyes containing eugenol and guaiacol, synthesis, antioxidant capacity, urease inhibitory properties and anti-Helicobacter pylori activity. Rev Roum Chim 2018; 63(3): 189–197.

31.

Kantar

Baltas

Karaoğlu

ŞA

, et al. New potential monotherapeutic candidates for Helicobacter pylori: Some pyridinazo compounds having both urease enzyme inhibition and anti-Helicobacter pylori effectiveness. Pharm Chem J 2021; 55: 246–252.

32.

Kantar

Akal

Kaya

, et al. Novel phthalocyanines containing resorcinol azo dyes; Synthesis, determination of pKa values, antioxidant, antibacterial and anticancer activity. J Organomet Chem 2015; 783: 28–39.

33.

Test method for antibacterial activity of textile materials: Parallel streak. AATCC Manual of International Test Methods and Procedures/2021, pp. 286–287, https://members.aatcc.org/4DCGI/download/k6n3D4lE7t/TM147.pdf (accessed 22 September 2023).

34.

Tong

SYC

Davis

Eichenberger

, et al. Staphylococcus aureus infections: Epidemiology, pathophysiology, clinical manifestations, and management. Clin Microbiol Rev 2015; 28(3): 603–661.

35.

Balasubramanian

Harper

Shopsin

, et al. Staphylococcus aureus pathogenesis in diverse host environments. Pathog Dis 2017; 75(1): ftx005.

36.

Chung

PY.

The emerging problems of Klebsiella pneumoniae infections: Carbapenem resistance and biofilm formation. FEMS Microbiol Lett 2016; 363(20): fnw219.

37.

Süpüren

Çay

Kanat

, et al. Antimicrobial fibers. Tekst Konfeksiyon 2006; 16(2): 80–89.