Phytochemical Constituents, Attenuated Total Reflectance Fourier Transform Infrared Analysis and Antimicrobial Activity of Four Plant Leaves Used for Preparing Rice Beer in Assam, India

Figures & data

TABLE 1 Content of different phytochemicals in the leaves of the four plant species

	Concentration in the plant leaves (DM)
Phytochemicals	A. heterophyllus	C. extensa	O. corymbosa	A. malaccensis
Polyphenols (% ± SD)	1.40 ± 0.28^b	0.62 ± 0.04^a	2.06 ± 0.39^c	1.05 ± 0.10^b
Alkaloids (mg/g ± SD)	6.00 ± 1.04^c	3.57 ± 0.15^b	3.57 ± 0.25^b	2.47 ± 0.2^a
Tannin (mg/g ± SD)	1.16 ± 0.06^b	1.95 ± 0.15^c	1.22 ± 0.02^b	0.75 ± 0.01^a
Terpenoids (mg/g ± SD)	5.79 ± 0.48^c	1.71 ± 0.53^a	3.55 ± 0.99^b	2.50 ± 0.25^ab
Flavonoids (mg/g ± SD)	1.35 ± 0.08^a	5.47 ± 0.20^c	6.82 ± 0.20^d	1.93 ± 0.32^b
Anthocyanin (mg/g ± SD)	0.23 ± 0.001^a	0.23 ± 0.002^a	0.45 ± 0.004^b	0.59 ± 0.011^c
Gylcosides (mg/g ± SD)	1.46 ± 0.02^a	1.45 ± 0.08^a	1.52 ± 0.03^a	1.52 ± 0.07^a
Anthraquinone (mg/g ± SD)	0.14 ± 0.001^b	0.13 ± 0.002^a	0.17 ± 0.001^c	0.18 ± 0.002^d
Saponins (mg/g ± SD)	1.49 ± 0.07^c	1.78 ± 0.04^d	1.12 ± 0.03^a	1.26 ± 0.02^b
Phytosterols (mg/g ± SD)	0.14 ± 0.02^a	0.57 ± 0.04^b	0.70 ± 0.03^c	0.14 ± 0.04^a

DM: dry mattern = 3

Different superscripted alphabets along the rows represent the LSD at p < 0.05.

Figure 1 FTIR spectra of the four different extracts of A. heterophyllus.

Figure 2 FTIR spectra of the four different extracts of C. extensa.

Figure 3 FTIR spectra of the four different extracts of O. corymbosa.

Figure 4 FTIR spectra of the four different extracts of A. malaccensis.

TABLE 2 The functional groups detected by ATR-FTIR analysis of the water, methanol, ethyl acetate, and hexane extracts of the four plant species

Functional groups	Peak ranges (cm^–1)	A. heterophyllus				C. extensa				O. corymbosa				A. malaccensis
		H2O	MeOH	EA	Hex	H2O	MeOH	EA	Hex	H2O	MeOH	EA	Hex	H2O	MeOH	EA	Hex
Phenolic groups	3371/3369/3464/3324/3316	√	√	√	x	√	√	√	x	√	√	√	x	√	√	√	x
Carboxylic acids	3397/3392/2832/1046	√	√	√	x	√	x	x	√	√	√	x	√	√	√	x	√
Alcohols/Polyols	3397/3387/1226	√	x	√	x	x	x	√	x	√	x	√	x	√	x	√	x
Primary amines	3346/772	√	√	√	x	√	√	√	x	√	√	√	x	√	√	√	x
Alkynes	3308/651/613	x	x	x	x	√	√	x	√	√	√	x	√	√	√	x	√
Alkanes	3310/2953/2886/2863/2924/1457	√	√	√	√	√	√	√	√	√	√	√	√	√	√	√	√
Ketones	1637/1739	x	x	√	x	x	x	√	x	x	x	√	x	x	x	√	x
Carbonyl groups	1733/1637/1249	√	x	√	x	√	x	√	x	x	x	√	x	√	x	√	x
Nitro compounds	1538	x	x	√	x	x	x	√	x	x	x	√	x	x	x	√	x
Aromatics	1462	x	x	√	√	x	x	√	√	x	x	√	√	x	x	√	√
Aromatic amines	1411	x	x	√	x	x	x	√	x	x	x	√	x	x	x	√	x
Aliphatic amines	1389/1114/1038	x	√	√	x	x	√	x	√	x	√	x	√	x	√	√	√
Esters/ ethers	1311/1334	x	x	√	x	√	x	√	x	x	x	√	x	√	x	√	x
Alkyl halides	1168/771/767/609/578/506	√	√	√	√	√	√	√	√	√	√	√	√	√	√	√	√
Aldehydes	781	√	x	x	x	x	x	x	x	√	x	x	x	x	x	x	x

H₂O: water; MeOH: methanol; EA: ethyl acetate; Hex: hexane; √: present; x: absent.

TABLE 3 Antimicrobial activity of the four plant extracts

Plant species	Solvent	Diameter of zone of inhibition (mm ± SD; n = 3)
		F. oxysporum	C. albicans	S. cerevisae	E. coli	S. aureus	L. plantarum	B. subtilis
A. heterophyllus	H2O	NA	NA	NA	NA	NA	NA	NA
	MeOH	NA	NA	NA	NA	NA	NA	NA
	EA	NA	16.00 ± 0	NA	33.25 ± 2.22	23.50 ± 0.58	NA	18.22 ± 0.42
	Hex	NA	NA	NA	3.00 ± 0.60	NA	NA	NA
C. extensa	H2O	NA	NA	NA	NA	NA	NA	NA
	MeOH	NA	NA	NA	12.75 ± 0.50	NA	NA	NA
	EA	NA	10.00 ± 0	NA	16.50 ± 0.58	12.00 ± 0.00	NA	12.45 ± 0.24
	Hex	NA	NA	NA	NA	NA	NA	NA
O. corymbosa	H2O	NA	NA	NA	NA	NA	NA	NA
	MeOH	NA	5.00 ± 0.77	NA	11.50 ± 0.58	5.00 ± 0.77	NA	5.00 ± 0.24
	EA	NA	NA	NA	16.00 ± 1.41	12.75 ± 0.50	NA	10.08 ± 0.55
	Hex	NA	NA	NA	NA	5.00 ± 0.77	NA	NA
A. malaccensis	H2O	NA	NA	NA	6.25 ± 0.23	NA	NA	NA
	MeOH	NA	11.25 ± 0.50	NA	19.50 ± 1.29	12.25 ± 0.83	NA	10.88 ± 0.41
	EA	NA	14.00 ± 0.00	NA	29.00 ± 2.45	17.50 ± 0.58	NA	18.19 ± 0.48
	Hex	NA	15.50 ± 1.29	NA	22.00 ± 3.37	NA	NA	NA

H₂O: water; MeOH: methanol; EA: ethyl acetate; Hex: hexane; NA: no activity.

TABLE 4 Minimum inhibitory concentration (MIC) values of the four plant extracts

		Concentration (µg/mL)
Plant species	Solvent	C. albicans	E. coli	S. aureus	B. subtilis
A. heterophyllus	EA	75	50	60	130
	Hex	–	270	–	–
C. extensa	MeOH	–	170	–	–
	EA	120	80	200	200
O. corymbosa	MeOH	150	120	190	300
	EA	–	70	130	200
	Hex	–	–	280	–
A. malaccensis	H2O	–	350	–	–
	MeOH	150	50	130
	EA	100	45	100	180
	Hex	120	60	–	–
Streptomycin		–	20	50	30
Chloramphenicol		25	–	–	–

H₂O: water; MeOH: methanol; EA: ethyl acetate; Hex: hexane.