Antibacterial activity of tannins isolated from Sapium baccatum extract and use for control of tomato bacterial wilt

Abstract

In the search for new antibacterial agents from natural sources, we revealed that a crude methanol extract of Sapium baccatum was highly active against Ralstonia solanacearum, a causal agent of a serious disease called bacterial wilt of tomato. The bioassay-guided fractionation of this extract resulted in the isolation of seven known active compounds, including gallic acid, methyl gallate, corilagin, tercatain, chebulagic acid, chebulinic acid, and quercetin 3-O-α-L-arabinopyranoside. Their chemical structures were determined by electrospray ionization mass spectrometry and nuclear magnetic resonance spectroscopy. An in vitro antibacterial bioassay using a broth microdilution method revealed that, except for quercetin 3-O-α-L-arabinopyranoside (MIC = 250 μg/mL), the isolated compounds exhibited strong antibacterial activity against R. solanacearum (MIC = 26–52 μg/mL). Among the seven compounds, methyl gallate exhibited the strongest broad-spectrum activity against most of the plant pathogenic bacteria tested (MIC = 26–250 μg/mL). In the in vivo experiments, the crude extract of S. baccatum at 2000 and 1000 μg/mL reduced the development of tomato bacterial wilt by 83 and 63%, respectively, under greenhouse conditions after 14 days of infection. The results suggested that the extracts of S. baccatum or isolated tannins could be used as natural bactericides for the control of bacterial wilt of tomato.

In Vitro Antioxidant and Anti-Propionibacterium acnes Activities of Cold Water, Hot Water, and Methanol Extracts, and Their Respective Ethyl Acetate Fractions, from Sanguisorba officinalis L. Roots

“…In addition, catechin, catechin gallate, and epicatechin gallate were identified in the HWE-EA and ME-EA, and their oligomers or polymers are known to form condensed tannins (procyanidins). Recently, several tannins were used as feed additives to control diseases in poultry farms [ 44 ] due to their antibacterial activity [ 45 , 46 ].…”

Biological Control of Tomato Bacterial Wilt, Kimchi Cabbage Soft Rot, and Red Pepper Bacterial Leaf Spot Using Paenibacillus elgii JCK-5075

“…The antibacterial assays of the culture filtrate of JCK-5075, crude substances (80% ethanol crude of Diaion HP-20), and PGPs, were conducted in a 96-well plate for microorganisms as previously reported, using the broth dilution method ( Vu et al, 2017 ). Two-fold serial dilutions were performed with 10% of the culture supernatant, 100 μg ml –1 of crude substances, and 32 μg ml –1 of PGPs.…”

Nano‐hydrogel embedded with quercetin and oleic acid as a new formulation in the treatment of diabetic foot ulcer: A pilot study

“…The clinical evidence herein highlighted by this formulation is in agreement with the action of each compound used alone. In fact, Qu by itself has strong antimicrobial and antioxidant activity, [29][30][31] while AO increases the expression of vascular endothelial growth factoralpha (VEGF-α) and interleukin-1beta (IL-1β). 32 Finally, several authors documented that the treatment of DFUs accounts for approximately one-third the total cost of diabetic care, 33 but only few patients, about 20%, have unhealed DFUs at 1 year 34,35 and about 40% have a recurrence in 1 year.…”