Investigation of the inhibitory properties of some phenolic standards and bee products against human carbonic anhydrase I and II

Figures & data

Table 1. RP-HPLC-UV validation parameters of the studied phenolic compounds.

Compounds	R^2	%RSD (retention time)	%RSD (area)	LOD^a	LOQ^a
Gallic acid	0.999	0.210	1.941	0.022	0.067
Protocatechuic acid	0.999	0.871	1.920	0.042	0.128
p-OH Benzoic acid	0.998	0.351	3.055	0.036	0.109
Catechin	0.997	0.492	4.279	0.040	0.121
Vanillic acid	1.000	0.828	2.066	0.025	0.075
Caffeic acid	0.998	0.179	4.039	0.062	0.187
Syringic acid	1.000	0.550	0.848	0.009	0.027
Epicatechin	0.999	0.429	3.819	0.030	0.090
p-Coumaric acid	0.999	0.204	1.562	0.010	0.030
Ferulic acid	0.999	0.222	1.301	0.011	0.033
Rutin	1.000	0.234	3.139	0.041	0.123
Daidzein	0.998	0.174	1.545	0.018	0.054
t-Cinnamic acid	1.000	0.262	1.071	0.014	0.042
Caffeic acid phenyl  ester CAPE	0.994	0.229	5.833	0.043	0.130

^aValues are expressed as mg/L.

Table 2. Phenolic composition of the studied honey-bee products (μg/g).

Bee products	GA	ProCA	BA	CLA	VA	SA	CA	COU	FER	CAPE	QUE	CAT	RUT
Heather honey-I	0.521	22.456	28.410	nd	2.490	nd	0.890	3.124	nd	nd	8.560	16.04	4.403
Heather honey-II	0.440	18.876	16.400	nd	1.830	nd	1.402	2.200	nd	nd	12.40	13.76	6.132
Rhododendron honey-I	0.052	1.052	5.780	nd	0.423	nd	4.120	3.980	0.526	nd	2.400	nd	0.090
Rhododendron honey-II	0.034	3.220	11.200	nd	-	nd	0.582	5.407	2.504	nd	3.880	nd	0.055
Chestnut honey-I	1.100	6.560	22.405	nd	2.420	nd	6.450	8.405	2.050	nd	4.220	nd	3.445
Chestnut honey-II	0.880	8.400	14.560	nd	3.050	nd	4.780	5.080	1.470	nd	2.920	nd	1.420
Propolis-I	5.560	7.405	34.150	14.415	28.140	4.400	130.100	72.400	248.025	1478.12	450.730	14.430	102.600
Propolis-II	1.422	3.484	55.330	10.170	34.770	-	241.333	58.203	174.320	898.080	560.450	3.435	124.900
Pollen-I	3.450	nd	8.440	nd	8.450	3.552	24.320	33.550	6.740	146.441	42.455	nd	24.478
Pollen-II	2.056	nd	14.700	1.100	5.510	5.860	16.100	27.110	11.700	210.036	60.036	1.170	30.170

GA: gallic acid; ProCA: protocatechuic acid; BA: p-OH benzoic acid; CLA: chlorogenic acid; VA: vanillic acid; SA: syringic acid; CA: caffeic acid; COU: p-coumaric acid; CAPE: caffeic acid phenyl ester; QUE: quercetin; CAT: catechin; RUT: rutin.

Table 3. Inhibitory effects of some bee products and polyphenols against hCA I and hCA II.

	Samples	Total phenolic content (mg GAE/100g)	hCA I IC50 (μg/mL)	hCA II IC50 (μg/mL)
Honey	Heather honey-I	46.770 ± 1.880	8.105 ± 1.105	16.830 ± 1.050
	Heather honey-II	43.270 ± 2.160	7.050 ± 0.082	25.120 ± 1.542
	Rhododendron honey I	32.120 ± 3.120	3.012 ± 0.042	9.720 ± 1.220
	Rhododendron honey II	24.151 ± 1.062	3.580 ± 0.072	10.450 ± 0.556
	Chestnut honey I	105.206 ± 2.550	1.320 ± 0.152	2.323 ± 0.024
	Chestnut honey II	94.404 ± 1.682	1.522 ± 0.222	2.880 ± 0.036
Propolis	Propolis-I	850.460 ± 12.400	1.273 ± 0.352	0.486 ± 0.032
	Propolis-II	788.120 ± 10.520	1.374 ± 0.066	0.612 ± 0.010
Pollen	Pollen-I	255.20 ± 12.330	1.410 ± 0.032	3.320 ± 0.028
	Pollen-II	247.620 ± 5.250	1.144 ± 0.010	2.880 ± 0.020
Polyphenols	Gallic acid	–	0.009 ± 0.000	0.035 ± 0.012
	Protocatechuic acid	–	0.134 ± 0.005	0.320 ± 0.020
	Quercetin	–	0.008 ± 0.001	0.019 ± 0.002
	Catechin	–	0.002 ± 0.000	0.034 ± 0.002
	Tannic acid	–	0.035 ± 0.000	0.009 ± 0.001
	Chrysin	–	0.017 ± 0.001	0.044 ± 0.001
CA inhibitors	Acetazolamide	–	0.011 ± 0.002	0.004 ± 0.001
	Sulfanilamide	–	0.014 ± 0.002	0.014 ± 0.001

Table 4. Phenolic standards found in the studied samples.

Phenolic standards	Molecules formulas
Gallic acid
Protocatechuic acid
Quercetin
Catechin
Tannic acid
Chrysin