Table 2.

Antimicrobial true alkaloid compounds 73–97.

Type	Compound	Structure	Source	Antimicrobial Activity
Pyridine	2-methoxy-4-(2-(2-pyridine)ethy)- phenol [104]	73 in Figure 6	Zingiberis rhizome.	Antifungal activity against C. albicans, ith a 1.0 mg/mL MIC value.
Isoquinoline	Chelerythrine [105]	74 in Figure 6	Toddalia asiatica (Linn) Lam.	Activity against S. aureus and MRSA.
	Palmatine [106]	75 in Figure 6	Coptis chinensis.	Activity against Helicobacter pylori, with MIC values ranging from 75 to 200 μg/mL.
	Tetrandrine [107]	76 in Figure 6	Stephania tetrandra S. Moore.	Activity against S. aureus, with MIC values ranging from 125 to 250 μg/mL.
	Bicuculline [108]	77 in Figure 6	Fumaria and Corydalis.	Antibacterial activity against E. coli, P. aeruginosa, P. mirabilis, K. pneumoniae, A. baumannii, S. aureus and B. subtilis, as well as antifungal activity against C. albicans.
	Protopine [109]	78 in Figure 6	Fumaria and Corydalis.	Antibacterial activity against E. coli, P. aeruginosa, P. mirabilis, K. pneumoniae, A. baumannii, S. aureus and B. subtilis, as well as antifungal activity against C. albicans.
	Magnoflorine [110]	79 in Figure 6	Coptidis rhizome, Mume fructus, Schizandrae fructus, and Magnolia grandiflora.	Antimicrobial activity against enterohemorrhagic E. coli, S. aureus, and C. albicans. It also has antiviral activity against HSV-1.
Oxazole	2-terButyl-4-(4-chlorophenyl)oxa-zole [111]	80 in Figure 6	Synthesized compounds.	Activity against B. subtilis, S. aureus, E. coli, and K. pneumonia.
	4-(4-bromophenyl)-2-tert-butylo-azole [111]	81 in Figure 6	Synthesized compounds.	Activity against B. subtilis, S. aureus, E. coli, and K. pneumonia.
	4-(5-methyl-1,2,4-oxadiazol-3-yl-phenol [112]	82 in Figure 6	Synthesized compounds.	MIC of 25 μg/mL against S. aureus and A. niger
	4-(3-methyl-1,2,4-oxadiazol-5-yl-phenol [112]	83 in Figure 6		MIC of 25 μg/mL against E. coli and A. niger
	4-(5-methyl-1,3,4-oxadiazol-2-yl-phenol [112]	84 in Figure 6		MIC of 25 μg/mL against S. aureus, E. coli and A. niger
Isoxazole	(E)-4-((5-amino-4-(phenyldiazen-yl)-1H-pyrazol-3-yl)amino)-N-(5-methylisox zol-3-yl)benzenesulfonamide [113]	85 in Figure 6	Synthesized compounds.	Antibacterial activity against S. pneumoniae, B. subtilis, P. aeruginosa, and E. coli, with zone inhibition diameters of 16.70, 19.20, 13.30 and 13.60 cm, respectively. In addition, antifungal activity against A. fumigatus, Syncephalastrum racemosum, G. candidum, and C. albicans, with zone inhibition diameters 16.80, 13.40, 19.60 and 15.90 cm, respectively.
	(E)-4-((5-amino-4-((4-methoxyph-enyl)diazenyl)-1H-pyrazol-3-yl)a-mino)-N-(5-methylisoxazol-3-yl)-benzenesulfonamide [113]	86 in Figure 6	Synthesized compounds.	Antibacterial activity against S. pneumoniae, B. subtilis, P. aeruginosa, and E. coli, with zone inhibition diameters of 18.30, 22.60, 19.30, and 17.80 cm, respectively. In addition, antifungal activity against A. fumigatus, S. racemosum, G. candidum, and C. albicans, with zone inhibition diameters of 20.60, 16.70, 22.40, and 17.60 cm, respectively.
	(E)-4-((5-amino-4-((4-chlorophenyl)diazenyl)- 1H-pyrazol-3-yl)- amino)-N-(5-methylisoxazol- -3-yl)benzenesulfonamide [113]	87 in Figure 7	Synthesized compounds.	Antibacterial activity against S. pneumoniae, B. subtilis, P. aeruginosa, and E. coli with zone inhibition diameters of 23.0, 32.40, 17.30, and 19.90 cm, respectively. In addition, antifungal activity against A. fumigatus, S. racemosum, G. candidum, and C. albicans, with zone inhibition diameters of 23.70, 19.70, 28.70 and 25.40 cm, respectively.
	4-(6-amino-3,5-dicyano-4-(4-met- hoxyphenyl)-2-oxopyridin- -1(2H)-yl)-N-(5-methylisoxazol-3-yl)benzenesulfonamide [113]	88 in Figure 7	Synthesized compounds.	Antibacterial activity against S. pneumoniae, B. subtilis, P. aeruginosa, and E. coli with zone inhibition diameters of 16.9, 18.2, 9.8 and 11.9 cm, respectively. In addition, antifungal activity against A. fumigatus, S. racemosum, G. candidum, and C. albicans, with zone inhibition diameters of 16.2, 15.0, 17.6 and 14.10 cm, respectively.
Thiazole	Camalexin [114]	89 in Figure 7	Arabidopsis thaliana.	Antifungal activity against Botrytis cinerea
	(E)-2-(1-(2-(4-butylphenyl)-4-methylthiazol-5-yl)ethylidene)hy-drazinecarboximidamide [115]	90 in Figure 7	Synthesized compounds.	Exhibited MIC values ranging from 1.38 to 2.77 μg/mL against MRSA, VISA and VRSA
	(E)-2-(1-(2-([1,1′-biphenyl]-4-yl)-4-methylthiazol-5-yl)ethylidene)hydrazinecarboximidamide [115]	91 in Figure 7	Synthesized compounds.	Exhibited MIC values ranging from 0.70 to 1.40 μg/mL against MRSA, VISA and VRSA
Quinazoline	2-(6,7-Dimethoxy-3- benzyl-4-oxo-3,4-dihydro quinazoline-2-ylthio) nicotinic acid [116]	92 in Figure 7	Synthesized compounds.	Significant antimicrobial activity.
	1-(4-Hydroxybenzylidene)-4-(4-(4-oxo-2-phenylquinazolin-3(4H)-yl) phenyl) semicarbazide [117]	93 in Figure 7	Synthesized compounds.	Antibacterial activity against S. aureus, S. epidermidis, M. luteus, B. cereus, E. coli, and P. aeruginosa.
	6-(2-Thienyl)-2-iodo-benzimidaz- o [1,2-c]-quinazoline [118]	94 in Figure 7	Synthesized compounds.	Antibacterial and antifungal activity against E. coli, S. aureus, B. subitilis, S. cerevisiae, and C. albicans.
Quinoline	Antidesmone [119]	95 in Figure 7	Waltheria indica.	Activity against Sclerotinia sclerotiorum, Botryosphaeria dothidea, Pestalotiopsis guepinii, Colletotrichum musae, Colletotrichum orbiculare, Parasterope longiseta, and Phytophthora nicotianae.
	Waltherione C [119]	96 in Figure 7	Waltheria indica.	Activity against S. sclerotiorum, B. dothidea, Pestalotiopsis guepini, C. musae, C. orbiculare, P. longiseta, and P. nicotianae.
	Evocarpine [120]	97 in Figure 7	Fructus Euodiae.	Significant activity against MRSA, with an MIC value of 8 μg/mL, while the standard drugs oxacillin, erythromycin, and tetracycline had MIC values of ≥128 μg/mL.