In the study, the use of analytical methods looking into compound bioactivity were applied to durian shells isolating two new triterpenoids, two new phenolics, and seven new glycoside esters.
According to the team from Guangdong Pharmaceutical University in China, these compounds demonstrated significant inhibitory activities on lipopolysaccharide (LPS)-induced nitric oxide (NO) production.
“The results indicated that the NO inhibitory activity of durian shells may be due to the presence of glycosides and triterpenoids,” the research paper stated.
“Moreover, this study provided motivation for the ecological protection of durian shells.”
This mechanism has been implicated in the inset of chronic diseases, such as inflammatory, atherosclerosis, cancer, diabetes, and coronary heart diseases.
LPS is a component made by gram-negative bacteria and is one of the most powerful activators of the immune response including the release of the pro-inflammatory mediator NO.
Led by Dr Xiangjiu He, a researcher based at the University, the team air-dried 20kg of durian shells, which were then were pulverized, extracted, filtered and concentrated to form three separate fractions.
Further fractionation was then carried out and then analysed using Gas Chromatography (GC) methods and NO inhibitory assays.
Findings revealed that around two-thirds of the isolated compounds from durian shell showed pronounced inhibitory effects on NO production.
All triterpenoids showed significant inhibitory effects with the ursolic type triterpenoids, in particular exhibiting more potential NO inhibitory activity compared with the oleanolic type triterpenoids.
However, the coumarin derivatives extracted did not show NO inhibitory activity.
“These structure-activity relationships provided useful clues for predicting the NO inhibitory activity of triterpenoids and other compounds from durian,” said the study team.
“The assay was applied to evaluate the cytotoxicity of the isolated phenolics. Results indicated that the NO inhibitory activities of all compounds were not due to their cytotoxicity.”
The wonder of durian
As found in previous studies, durian fruit is abundant in nutritious, bioactive components, such as triterpenoids, coumarins, phenolics, lignans, flavonoids, sulphur-containing compounds, and some esters.
The durian shell has been studied as a novel and potential biosorbent for hexavalent chromium removal from synthetic wastewater. Results found that the maximum biosorption capacity of durian shell was 117 milligrams per gram (mg/g).
One drawback to the fruit is its spiny and hard shell, which is difficult to dispose and is treated as agricultural waste.
The team think that with increasing environmental awareness and now the shell’s nutritional qualities the potential value of these shells could well be re-evaluated.
Source: Food Chemistry
Published online ahead of print:doi.org/10.1016/j.foodchem.2017.08.097
“Novel triterpenoids and glycosides from durian exert pronounced anti-inflammatory activities.”
Authors: Jianying Feng, Xiaomin Yi, Wenjie Huang, Yihai Wang, Xiangjiu He