Chemical and physicochemical characterizations of the water-soluble fraction of the Commiphora Africana exudate

An Innovative Methodology to Characterize, at the Molecular Scale, Interactions in Polysaccharide Aqueous Solutions

Characterizing molecular interactions at the microscopic level remains difficult and, therefore, represents a key target to better understand macromolecule and biomacromolecule behaviors in solution, alone, or in mixtures with others. Therefore, accurate characterization in liquid media, especially in aqueous solutions, without causing any perturbation of the system in which they are studied, is quite difficult. To this purpose, the present paper describes an innovative methodology based on fluorescence spectrophotometry. Two molecular fluorescent probes, namely 8-anilino-1-naphtalenesulfonic acid (ANS) and 2-benzofuryl-3-hydroxy-4(1H)-quinolone (3HQ-Bf), were selected to characterize, respectively, the dipole-dipole interactions and hydrophobic micro-domains, for the first one, and hydrogen bonding, for the second. As a support to study molecular interactions, xanthan, galactomannan, and corresponding mixtures of these substances which are well known to exhibit a synergy of interactions in well-defined mixture conditions were chosen. Once the methodology was set up, the existence of the three types of interactions in these systems was demonstrated, thus allowing the elucidation of the mechanisms of interactions at the molecular scale.

Plants arabinogalactans: From structures to physico-chemical and biological properties

Arabinogalactans (AGs) are plant heteropolysaccharides with complex structures occasionally attached to proteins (AGPs). AGs in cell matrix of different parts of plant are freely available or chemically bound to pectin rhamnogalactan. Type I with predominantly β-d-(1 → 4)-galactan and type II with β-d-(1 → 3) and/or (1 → 6)-galactan structural backbones construct the two main groups of AGs. In the current review, the chemical structure of AGs is firstly discussed focusing on non-traditional plant sources and not including well known industrial gums. After that, processes for their extraction and purification are considered and finally their techno-functional and biological properties are highlighted. The role of AG structure and function on health advantages such as anti-tumor, antioxidant, anti-ulcer- anti-diabetic and other activites and also the immunomodulatory effects on in-vivo model systems are overviewed.

Ecological studies of Commiphora genus (myrrha) in Makkah region, Saudi Arabia

Commiphora, myrrha, is a pantropical genus and perform well in arid and semi-arid environments. This genus has economic importance. Distribution of Commiphora species and their associated species in Saudi Arabia has not been studied to date. The current study report on (a) characterization and distribution of plant communities including Commiphora species and (b) assessment of factors influencing ecological preferences of these species. Five species of Commiphora are recorded inhabiting mountain slopes, steep escarpments or hills consisting of igneous rocks, either granites or basalt with drought prone shallow soil. One hundred and twenty-six plant species belonging to 95 genera and 35 families were found associated with different Commiphora species. Therophytes showed the most frequent life form class and Sudanian region elements recorded the highest phytogeographical units (28%) followed by Tropical elements. Field study showed that Commiphora gileadensis and C. quadricincta preferred granite and basalt rocks exposed to erosion, while C. myrrah, C. kataf and C. habessinica grow on resistant coarse pink granite. The analysis of 240 sampling stands with TWINSPAN revealed the vegetation of Commiphora habitats into eight vegetation groups; each group represented a distinct microhabitat. Dendrogram obtained from a hierarchical classification showed that habitats of C. gileadinsis and C. quadricincta are more similar than those of other species. This similarity was confirmed by Jaccard and Sorenson similarity indices and by Pearson correlation coefficient. This investigation compiled the information/data to facilitate future range management of Commiphora species.