Biological exploration of a novel 1,2,4-triazole-indole hybrid molecule as antifungal agent

Figures & data

Figure 1. Chemical structure of 8 g.

Table 1. Antifungal susceptibilities of Candida spp. to 8 g.

Species (no. of isolates)	Antifungal agent	MIC (µg/mL)
		Range	Geometric mean	MIC90
C. albicans (27)	8g	< 0.016–4	0.038	0.5
	fluconazole	< 0.125 – > 64	0.696	8
	voriconazole	< 0.016 – > 8	0.042	0.25
C. glabrata (13)	8g	< 0.06–0.5	0.06	0.25
	fluconazole	0.016 – > 64	4	64
	voriconazole	0.016–4	0.25	1
C. krusei (15)	8g	0.016–1	0.109	0.125
	fluconazole	8 – > 64	23	64
	voriconazole	0.016–4	0.158	0.125
C. parapsilosis (20)	8g	< 0.016–0.125	0.029	0.0625
	fluconazole	< 0.125 – > 64	0.661	8
	voriconazole	< 0.016–0.25	0.017	0.125
C. tropicalis (6)	8g	< 0.016–1
	fluconazole	< 0.125–64
	voriconazole	< 0.016–0.5
Candida spp. (81)	8g	< 0.016–4	0.048	0.5
	fluconazole	< 0.125 – > 64	2	64
	voriconazole	< 0.016 – > 8	0.059	1

Figure 2. Survival curve of mice after treatment with fluconazole (3 x 5 mg/kg per os, □) or 8 g (2 x 30 mg/kg ip, Δ; 3 x 20 mg/kg ip, ▲). Control group (●). **p < 0.01; ***p <0 .001.

Table 2. Hydrolysis inhibition of the 1-octadecanoyl 2–(1-¹⁴C) eicosatetraenoyl glycerol-3-phosphocholine after treatment with bromophenacyl bromide (BpB) and 8 g.

	Inhibitors (Mean ± SEM)
	Control	BpB	8g
phospholipids	1.18 ± 0.18	1.32 ± 0.01	1.10 ± 0.01
mono- & diglycerides	0.12 ± 0.04	0.12 ± 0.01	0.14 ± 0.02
arachidonic acid	0.22 ± 0.04	0.11 ± 0.01	0.12 ± 0.02
triglycerides & others	0.26 ± 0.13	0.31 ± 0.16	0.12 ± 0.01
total lipids	1.79 ± 0.05	1.86 ± 0.15	1.48 ± 0.04
PLA2 like activity (%)	12.5 ± 2.6	5.9 ± 0.79	8.2 ± 1.06

Radioactivity of the lipid classes is expressed in nmol.L⁻¹.min⁻¹/10⁸ cells. Phospholipase activity is expressed as the percentage of fatty acid released from the total radiolabelled phospholipids.

Table 3. Sterol profile of C. albicans (CAAL93), C. krusei (CAKR7) and C. glabrata (CAGL2) untreated and treated with fluconazole (FLU: 4 µg/mL) or 8 g (4 ng/mL or 4 µg/mL). –: not detected.

		CAAL93			CAKR7			CAGL2
		control	8g	FLU	control	8g	FLU	control	8g	FLU
	R.T.		4 ng/mL	4 µg/mL		4 µg/mL	4 µg/mL		4 µg/mL	4 µg/mL
zymosterol	9.34	4.8	–	–	2.4	–		–	–	–
24-ethyl-cholesta-5,7,22-trienol	9.49	–	–	8.5	–	–	–	–	–	–
ergosterol	9.55	69.4	21.6	–	83.1	60.1	84.3	78.4	41.6	79.9
14α-methylepisterol	9.71	–	13.5	30.7	–	3.5		–	2.6	–
ergosta-7,22-dienol	9.73	5.5	–	–	–	–	–	–	–	–
fecosterol	9.80	–	–	–	1.9	–	1.8	–	–	–
14α-methylfecosterol	9.97	–	10.0	10.8	–	4.9		–	3.5	–
ergostadien-3β-ol (5,7 or 5,8)	10.05	–	–	–	1.1	–	1.1	3.7	2.2	7.6
episterol	10.26	3.4	–	–	–	–	–	1.9	–	3.5
14α-3,6-diol	10.41	–	–	–	–			–	23.4	–
lanosterol	10.55	5.2	35.4	34.2	0.7	24.2	1.8	3.6	–	1.9
obtusifoliol	10.60	–	–	–	–	–	–	–	23.8	–
4,4-dimethylcholesta-8,24-dienol	10.80	1.4			1.2		1.1	2.7		2.1
eburicol	11.20	–	19.0	15.7	–	3.9	–	–	0.7	–
other sterols		10.3	0.5	0	9.5	3.5	10.0	9.6	2.2	7.1

R.T.: retention time; Other sterols: sterols <1% or unidentified sterols. Bold: sterols of major interest (lanosterol = precursor, ergosterol = final product and 14a-3,6-diol = toxic final product)