Heavy Metals Analysis and Phytochemicals Screening of Indian Bamboo Sap (Bambusa Vulgaris) from Ikot Osurua, Ikot Ekpene Local Government Area of Akwa Ibom State Nigeria

The analysis of heavy metals concentration and phytochemical screening of Indian bamboo Sap (Bambusa vulgaris) in Ikot Osurua, Ikot Ekpene Local Government Area of Akwa Ibom State were carried out using standard analytical methods. The results of the analysis showed that: cadmium (Cd) (0.00393 ± 0.001(mg/L)), copper (Cu) (0.0011 ± 0.0001(mg/L)), Cobalt (Co) (<0.00001 ± 0(mg/L)), lead (Pb) (0.321 ± 0.001(mg/L)), Zinc (Zn) (0.6725 ± 0.00045(mg/L)), Chromium (Cr) (1.601 ± 0.009(mg/L)). These results were below International Organization of Vine and Wine Permissible Limit for Sap (OIV, 2008) standard when compared exceptions of Lead (Pb) and Chromium (Cr). The results of phytochemical screening revealed the presence of saponins (+ +), tannins (++), cardiac glycosides (+ +) and deoxy sugar (+) and Alkaloids (-) was absence. Therefore, purification system should be employed in the Indian Bamboo Sap to reduce the concentration a of Lead (Pb) and Chromium (Cr) to be in line with the OIV standard to avoid the effect of toxic doses of lead (Pb) and Chromium (Cr) when used for treatment. The various concentration of photochemical provides the therapeutic effect of the plant. Keywords; Heavy metals, phytochemical Screening, Analysis, Indian bamboo and Sap

NDP-rhamnose biosynthesis and rhamnosyltransferases: building diverse glycoconjugates in nature

Rhamnose is an important 6-deoxy sugar present in many natural products, glycoproteins, and structural polysaccharides. Whilst predominantly found as the l-enantiomer, instances of d-rhamnose are also found in nature, particularly in the Pseudomonads bacteria. Interestingly, rhamnose is notably absent from humans and other animals, which poses unique opportunities for drug discovery targeted towards rhamnose utilizing enzymes from pathogenic bacteria. Whilst the biosynthesis of nucleotide-activated rhamnose (NDP-rhamnose) is well studied, the study of rhamnosyltransferases that synthesize rhamnose-containing glycoconjugates is the current focus amongst the scientific community. In this review, we describe where rhamnose has been found in nature, as well as what is known about TDP-β-l-rhamnose, UDP-β-l-rhamnose, and GDP-α-d-rhamnose biosynthesis. We then focus on examples of rhamnosyltransferases that have been characterized using both in vivo and in vitro approaches from plants and bacteria, highlighting enzymes where 3D structures have been obtained. The ongoing study of rhamnose and rhamnosyltransferases, in particular in pathogenic organisms, is important to inform future drug discovery projects and vaccine development.

5-Deoxyadenosine Salvage by Promiscuous Enzyme Activity leads to Bioactive Deoxy-Sugar Synthesis in Synechococcus elongatus

Abstract7-Deoxysedoheptulose is an unusual deoxy-sugar, which acts as antimetabolite of the shikimate pathway thereby exhibiting antimicrobial and herbicidal activity. It is produced by the unicellular cyanobacterium Synechococcus elongatus PCC 7942, which has a small, stream-lined genome, assumed to be free from gene clusters for secondary metabolite synthesis. In this study, we identified the pathway for the synthesis of 7-deoxysedoheptulose. It originates from 5-deoxyadenosine, a toxic byproduct of radical S-adenosylmethionine (SAM) enzymes, present in all domains of life. Thereby we identified a novel 5-deoxyadenosine salvage pathway, which first leads to the synthesis and excretion of 5-deoxyribose and subsequently of 7-deoxysedoheptulose. Remarkably, all reaction steps are conducted by promiscuous enzymes. This is a unique example for the synthesis of a bioactive compound without involving a specific gene cluster. This challenges the view on bioactive molecule synthesis by extending the range of possible compounds beyond the options predicted from secondary metabolite gene clusters.

Characterization of highly active 2-keto-3-deoxy-L-arabinonate and 2-keto-3-deoxy-D-xylonate dehydratases in terms of the biotransformation of hemicellulose sugars to chemicals

Abstract2-keto-3-L-arabinonate dehydratase (L-KdpD) and 2-keto-3-D-xylonate dehydratase (D-KdpD) are the third enzymes in the Weimberg pathway catalyzing the dehydration of respective 2-keto-3-deoxy sugar acids (KDP) to α-ketoglutaric semialdehyde (KGSA). The Weimberg pathway has been explored recently with respect to the synthesis of chemicals from L-arabinose and D-xylose. However, only limited work has been done toward characterizing these two enzymes. In this work, several new L-KdpDs and D-KdpDs were cloned and heterologously expressed in Escherichia coli. Following kinetic characterizations and kinetic stability studies, the L-KdpD from Cupriavidus necator (CnL-KdpD) and D-KdpD from Pseudomonas putida (PpD-KdpD) appeared to be the most promising variants from each enzyme class. Magnesium had no effect on CnL-KdpD, whereas increased activity and stability were observed for PpD-KdpD in the presence of Mg2+. Furthermore, CnL-KdpD was not inhibited in the presence of L-arabinose and L-arabinonate, whereas PpD-KdpD was inhibited with D-xylonate (I50 of 75 mM), but not with D-xylose. Both enzymes were shown to be highly active in the one-step conversions of L-KDP and D-KDP. CnL-KdpD converted > 95% of 500 mM L-KDP to KGSA in the first 2 h while PpD-KdpD converted > 90% of 500 mM D-KDP after 4 h. Both enzymes in combination were able to convert 83% of a racemic mixture of D,L-KDP (500 mM) after 4 h, with both enzymes being specific toward the respective stereoisomer. Key points• L-KdpDs and D-KdpDs are specific toward L- and D-KDP, respectively.• Mg2+affected activity and stabilities of D-KdpDs, but not of L-KdpDs.• CnL-KdpD and PpD-KdpD converted 0.5 M of each KDP isomer reaching 95 and 90% yield.• Both enzymes in combination converted 0.5 M racemic D,L-KDP reaching 83% yield.

Functional exploration of the GH29 fucosidase family

The deoxy sugar l-fucose is frequently found as a glycan constituent on and outside living cells, and in mammals it is involved in a wide range of biological processes including leukocyte trafficking, histo-blood group antigenicity and antibody effector functions. The manipulation of fucose levels in those biomedically important systems may provide novel insights and therapeutic leads. However, despite the large established sequence diversity of natural fucosidases, so far, very few enzymes have been characterized. We explored the diversity of the α-l-fucosidase-containing CAZY family GH29 by bio-informatic analysis, and by the recombinant production and exploration for fucosidase activity of a subset of 82 protein sequences that represent the family’s large sequence diversity. After establishing that most of the corresponding proteins can be readily expressed in E. coli, more than half of the obtained recombinant proteins (57% of the entire subset) showed activity towards the simple chromogenic fucosylated substrate 4-nitrophenyl α-l-fucopyranoside. Thirty-seven of these active GH29 enzymes (and the GH29 subtaxa that they represent) had not been characterized before. With such a sequence diversity-based collection available, it can easily be used to screen for fucosidase activity towards biomedically relevant fucosylated glycoproteins. As an example, the subset was used to screen GH29 members for activity towards the naturally occurring sialyl-Lewis x-type epitope on glycoproteins, and several such enzymes were identified. Together, the results provide a significant increase in the diversity of characterized GH29 enzymes, and the recombinant enzymes constitute a resource for the further functional exploration of this enzyme family.

Cytotoxic, Anti-Migration, and Anti-Invasion Activities on Breast Cancer Cells of Angucycline Glycosides Isolated from a Marine-Derived Streptomyces sp.

Four angucycline glycosides were previously characterized from marine-derived Streptomyces sp. OC1610.4. Further investigation of this strain cultured on different fermentation media from that used previously resulted in the isolation of two new angucycline glycosides, vineomycins E and F (1–2), and five known homologues, grincamycin L (3), vineomycinone B2 (4), fridamycin D (5), moromycin B (7), and saquayamycin B1 (8). Vineomycin F (2) contains an unusual ring-cleavage deoxy sugar. All the angucycline glycosides isolated from Streptomyces sp. OC1610.4 were evaluated for their cytotoxic activity against breast cancer cells MCF-7, MDA-MB-231, and BT-474. Moromycin B (7), saquayamycin B1 (8), and saquayamycin B (9) displayed potent anti-proliferation against the tested cell lines, with IC50 values ranging from 0.16 to 0.67 μM. Saquayamycin B (9) inhibited the migration and invasion of MDA-MB-231 cells in a dose-dependent manner, as detected by Transwell and wound-healing assays.