Doubly linked, A-type proanthocyanidin trimer and other constituents of Ixora coccinea leaves and their antioxidant and antibacterial properties.
Phytochemical investigation of the ethyl acetate fraction of the methanol extract of the leaves of Ixora coccinea led to the isolation and identification of an A-type trimeric proanthocyanidin epicatechin-(2β→O→7, 4β→8)-epicatechin-(5→O→2β, 6→4β)-epicatechin named ixoratannin A-2 along with seven known compounds, epicatechin, procyanidin A2, cinnamtannin B-1, and four flavon-3-ol rhamnosides viz: kaempferol-7-O-α-L-rhamnnoside, kaempferol-3-O-α-L-rhamnoside, quercetin-3-O-α-L-rhamnopyranoside, and kaempferol-3,7-O-α-L-dirhamnoside. The structures were elucidated by the application of IR, UV, MS, 1D-, and 2D-NMR spectroscopic analyses and by comparison with literature data. Antioxidant evaluation of isolated compounds revealed that ixoratannin A-2 and cinnamtannin B-1 were the most active compounds in DPPH, inhibition of lipid peroxidation and nitric oxide radical scavenging assays. Antibacterial activities were assessed by means of agar-diffusion assays using Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus subtilis. All tested compounds inhibited the growth of B. subtilis, while only epicatechin and quercetin-3-O-α-L-rhamnopyranoside inhibited the growth of E. coli.
Idowu
Thomas Oyebode
TO
Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Nigeria.
Ogundaini
Abiodun Oguntuga
AO
Salau
Abiola Oladimeji
AO
Obuotor
Efere Martins
EM
Bezabih
Merhatibeb
M
Abegaz
Berhanu Molla
BM
D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000187:drug effects; D001713:Biphenyl Compounds / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects; D016166:Free Radical Scavengers / Q000494:pharmacology; D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D015227:Lipid Peroxidation / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D009549:Nigeria; D009569:Nitric Oxide / Q000096:biosynthesis; D019906:Nuclear Magnetic Resonance, Biomolecular; D010851:Picrates / Q000494:pharmacology; D018515:Plant Leaves / Q000737:chemistry; D044945:Proanthocyanidins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D019666:Rubiaceae / Q000737:chemistry*
D000900:Anti-Bacterial Agents; D000975:Antioxidants; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D006027:Glycosides; D010851:Picrates; D044945:Proanthocyanidins; C555286:ixoratannin A-2; C013221:proanthocyanidin; D009569:Nitric Oxide; C004931:1,1-diphenyl-2-picrylhydrazyl