Antimicrobial and antioxidant effects of phenolic constituents from Klainedoxa gabonensis

Figures & data

Table 1.  Zone of inhibition (Ø in mm) of MeOH extract (KGB), fractions A-D and compounds 1–12 from K. gabonensis in agar diffusion test with 20 μg/disk (Ø in mm, paper disk Ø, 6 mm).

Sample	Microorganism
	BS^a	SV^b	SA^c	EC^d	MM^e	CA^f	CV^g	CS^h	SS^i
KGB	16	13	17	18	17	18	15	11	13
Fraction A	9	10	9	11	-	10	11	-	-
Fraction B	8	9	8	9	11	10	10	-	-
Fraction C	16	17	20	18	18	17	16	10	12
Fraction D	18	17	22	18	19	18	16	12	14
1	15	12	18	15	14	15	14	12	11
2	12	10	13	11	18	16	15	12	10
3	16	15	16	12	13	14	14	11	9
4	15	14	18	14	15	17	14	9	10
5	12	11	11	8	10	14	-	-	-
6	8	10	11	7	9	12	-	-	-
7	9	8	7	-	-	11	-	-	-
8	9	8	-	7	-	10	-	-	-
9	12	12	10	8	9	14	-	-	-
10	10	7	12	7	8	10	-	-	-
11	8	11	11	7	9	8	-	-	-
12	9	8	7	7	9	10	-	-	-
RA	22	23	22	22	25	25	15	14	14

^aBacillus subtilis; ^bStreptomyces viridochromogenes; ^cStaphylococcus aureus; ^dEscherichia coli; ^eMucor miehei; ^fCandida albicans; ^gChlorella vulgaris; ^hChlorella sorokiniana; ⁱScenedesmus subspicatus. - Not active; RA, Reference antibiotics (Gentamycin for bacteria, Nystatin for fungi).

Table 2.  Minimum inhibition concentrations (μg/mL) of MeOH extract (KGB), fractions C-D and compounds 1-4 from K. gabonensis.

Sample	Microorganism
	BS^a	SV  ^b	SA^c	EC^d	MM^e	CA^f
KGB	20.7	33.2	35.4	18.4	21.3	21.4
Fraction C	22.4	30.3	4.5	16.3	10.5	15.5
Fraction D	15.5	22.6	45.3	20.4	14.5	20.1
1	25.9	98.5	31.4	30.3	31.4	30.6
2	115.1	120.1	29.3	-	15.4	22.3
3	22.0	32.5	62.4	-	51.4	50.1
4	23.5	33.3	36.7	48.3	17.5	21.5
RA	1.9	0.5	1.0	1.0	0.2	0.2

^aBacillus subtilis; ^bStreptomyces viridochromogenes; ^cStaphylococcus aureus; ^dEscherichia coli; ^eMucor miehei; ^fCandida albicans. - Not active; RA, reference antibiotics (Gentamycin for bacteria, Nystatin for fungi).

Table 3.  Free radical scavenging activity of crude extract (KGB), fractions A-D and compounds 1-4, 6, 9 and 10 against DPPH (1,1-diphenyl-2-picrylhydrazyl).

Sample	% Inhibition	IC50 ± SEM^a^)
KGB	92	10.45 ± 1.23^b
Fraction A	42	257.00 ± 1.75^b
Fraction B	55	152.00 ± 1.72^b
Fraction C	79	75.00 ± 1.85^b
Fraction D	94	5.5 ± 0.05^b
1	93	48.25 ± 0.25^c
2	93	47.85 ± 0.15^c
3	95	45.7 ± 0.35^c
4	94	45.5 ± 0.05^c
6	72	122.31 ± 1.35^c
9	56	151.25 ± 2.0^c
10	76	105.5 ± 0.35^c
Standard (BHA)^d	96	44.2 ± 0.02^c

Extract (KGB) and fractions A-D were tested at 20 mg/mL, compounds 1-4, 6, 9, 10 were tested at 1 mM. ^aStandard mean error. ^bIC₅₀ in μg/mL. ^cIC₅₀ in mM ^dBHA (3-t-butyl-4-hydroxyanisole).

Figure 1.  Structures of compounds 1-12 isolated from MeOH extract of Klainedoxa gabonensis.