Genetic diversity in Corchorus olitorius L. revealed by morphophysiological and molecular analyses

Optimization of microwave-enhanced extraction parameters to recover phenolic compounds and antioxidants from Corchorus olitorius leaves

Vegetables are industrial crops endowed with both nutritional and medicinal values. The overwhelming contributions of vegetables to human living in the form of nutrients and medicine cannot be under emphasised. Thus, this study examined the recoveries of phenolic compounds and antioxidants from Corchorus olitorius leaves using a microwave-enhanced extraction technique. Furthermore, the phenolic compounds in the leaf extract of C. olitorius were comprehensively identified using liquid chromatography-mass spectrometry quadrupole of flight (LC-QToF-MS). At the optimized conditions of microwave-enhanced extraction (extraction time of 131 s, microwave power 305 W, solvent/sample ratio of 12 mL/g, and ethanol concentration of 50%), total phenolic content (TPC) of 343.098 ± 3.05 mg GAE/10 g d.b., IC50 values of 68.89 ± 1.08 and 29.76 ± 1.00 µg/mL for 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6'-sulfonic acid) (ABTS) assays, respectively, were achieved. Furthermore, an aggregate of fourteen phenolic compounds that include 1-galloyl-glucose, 1,3,5-O-tricaffeoylquinic acid, procyanidin C-1, 4,4',5,6-tetrahydroxystilbene, 3,4,5-O-tricaffeoylquinic acid, 5-desgalloylstachyurin, sanguiin H-4, corilagin_1, 1-O-galloylpedunculagin, laevigatin A, pedunculagin, 2,4,6-tri-O-galloyl-β-D-glucose, 1,3,6-trigalloyl-β-D-glucose, and 1,2,3,6-tetra-O-galloyl-β-D-glucose was tentatively identified in the leaf extract of C. olitorius. In general, this study has established C. olitorius leaves as sources of phenolic compounds and natural antioxidants. Thus, the intake can continue to be promoted as a way forward in solving the problem of food insecurity.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11696-023-02771-x.

Response of Corchorus olitorius Leafy Vegetable to Cadmium in the Soil

Corchorus olitorius, a leafy vegetable with high nutrient content, is normally collected from the wild, in areas that are prone to cadmium (Cd) toxicity. However, studies on how Cd accumulation affects vegetative and reproductive traits of leafy vegetables in South Africa are limited. Therefore, this study tested the effect of Cd accumulation on C. olitorius morphological traits. Plants were grown under various Cd concentrations and studied for variation in vegetative and reproductive traits as well as accumulation in roots and shoots. Plants exposed to 5 mg/kg Cd had longer roots with higher moisture content, heavier fresh and dried stems, as well as dried leaves, which indicated a hormetic effect in C. olitorius after exposure to low Cd concentration in the soil. Again, plants treated with 5–10 mg/kg Cd, accumulated toxic (>10 mg/kg dry weight) Cd within shoots and roots, with minor morphological alterations. Plants could survive, with some morphological defects, Cd toxicity up to 20 mg/kg in soil. Only plants exposed to 5 mg/kg could reproduce. Cd accumulation increased with an increase in the soil, with higher accumulation in shoots. The translocation factor was high (>1) in all Cd concentrations. In conclusion, C. olitorius can accumulate toxic Cd, and yet grow and reproduce either normally or better than the control. The proposed dose of Cd that induces hormesis in C. olitorius is 5 mg/kg in the soil. Therefore, C. olitorius is suitable for phytoremediation of Cd contaminated soils, but unsafe for consumption when it grows in such areas.

A comparative assessment of phenotypic and molecular diversity in Doum (Hyphaene thebaica L.)

Doum palm (Hyphaene thebaica L.) has been reported as one of the most beneficial species worldwide. Its fruits are a good source of fibers, antioxidants, B-complex vitamins, essential minerals, monosaccharides, essential oil and flavonoids. Fruit extract shows anti-inflammatory, antioxidant, antimicrobial, anticancer and pharmacological potential. However, there is a lack of investigations dealing with its genetic diversity. Therefore, a collection of twelve mature female palm landraces grown in the botanical garden of Aswan, "Egypt" were used for genetic diversity assessment based on phenotypic and molecular levels. 18 vegetal and chemical traits were evaluated. Fifteen of them showed highly significant variation among the tested landraces. Euclidian-based-dendrogram discriminated the tested landraces based on their phenotypic similarities to three main clusters showing a high level of variability. Molecular analysis using inter simple sequence repeats (ISSR) vis-à-vis start codon targeted (SCoT) polymorphism markers displayed the relationships among the tested landraces molecularly. Both markers showed a reasonable degree of polymorphism, however SCoT was more effective than the ISSR by showing a higher percentage of polymorphism, polymorphism information content, resolving power and diversity index. Cluster analysis based on molecular data showed a clear relationship among the doum landraces. However, ISSR- and SCoT-based dendrograms were slightly different, and completely unlike that based on phenotypic data. Nevertheless, phenotypic and molecular evaluations might complement each other, and by data of both an excellent overview was obtained from principle coordinate analysis. The information herein is valuable and considered as a keystone for further proximate studies on doum genetic diversity to help in improvement and breeding approaches.