Effect of ascorbic acid on the photolysis of cyanocobalamin and aquocobalamin/hydroxocobalamin in aqueous solution: A kinetic study

Ahmad, Iqbal; Qadeer, Kiran; Hafeez, Amtul; Zahid, Saima; Sheraz, Muhammad Ali; Khattak, Saif ur Rehman

doi:10.1016/j.jphotochem.2016.08.004

Cited by 17 publications

(23 citation statements)

References 51 publications

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“… 924 The Co II side-product can be trapped by oxygen. 923 , 925 , 926 The photolysis mechanism and release quantum yields depend not only on the type of LG but also on experimental parameters including the solvent, the pH, the presence of specific enzymes, 888 , 894 , 901 , 927 − 929 and the nature of the lower axial base. 895 , 923 Cobalamin release mechanisms are discussed in more detail in a recent review by Jones.…”

Section: Photorelease From Coordination Compoundsmentioning

confidence: 99%

Visible-to-NIR-Light Activated Release: From Small Molecules to Nanomaterials

et al. 2020

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Photoactivatable (alternatively, photoremovable, photoreleasable, or photocleavable) protecting groups (PPGs), also known as caged or photocaged compounds, are used to enable non-invasive spatiotemporal photochemical control over the release of species of interest. Recent years have seen the development of PPGs activatable by biologically and chemically benign visible and near-infrared (NIR) light. These long-wavelength-absorbing moieties expand the applicability of this powerful method and its accessibility to non-specialist users. This review comprehensively covers organic and transition metal-containing photoactivatable compounds (complexes) that absorb in the visible- and NIR-range to release various leaving groups and gasotransmitters (carbon monoxide, nitric oxide, and hydrogen sulfide). The text also covers visible- and NIR-light-induced photosensitized release using molecular sensitizers, quantum dots, and upconversion and second-harmonic nanoparticles, as well as release via photodynamic (photooxygenation by singlet oxygen) and photothermal effects. Release from photoactivatable polymers, micelles, vesicles, and photoswitches, along with the related emerging field of photopharmacology, is discussed at the end of the review.

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Section: Photorelease From Coordination Compoundsmentioning

confidence: 99%

Visible-to-NIR-Light Activated Release: From Small Molecules to Nanomaterials

et al. 2020

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“…On the basis of previous reports, ,,− we proposed mechanistic details for the formation of C–N and C–O bonds. According to the articles reported in recent years, cyanocobalamin as a vitamin B 12 is converted to hydroxycobalamin in the presence of heat, water, and oxygen. ,,, …”

Section: Results and Discussionmentioning

confidence: 99%

“…According to the articles reported in recent years, cyanocobalamin as a vitamin B 12 is converted to hydroxycobalamin in the presence of heat, water, and oxygen. 20,68,72,73 The central cobalt cation in vitamin B 12 forms has an oxidation state of +3. Co(II) and hydroxyl radical are generated as a result of the homolytic cleavage of hydroxycobalamin.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Use of Vitamin B₁₂ as a Nontoxic and Natural Catalyst for the Synthesis of Benzoxazoles via Catechols and Primary Amines in Water under Aerobic Oxidation

Sharghi

Hosseini

Aboonajmi

et al. 2021

ACS Sustainable Chem. Eng.

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We report an efficient and environmentally friendly approach for the synthesis of benzoxazoles in water using vitamin B 12 (2 mol %) as a nontoxic and natural catalyst under ambient air as the oxidant. To achieve this goal, benzoxazoles were prepared in relatively high yields by the reaction of catechols with amines under air at 50 °C in the presence of vitamin B 12 . This work is the first report on the incorporation of a natural cobalt complex as a redox catalyst for the oxidation of catechols. Also, we applied gabapentin and tranexamic acid, with an amine functional group, known as to have anticonvulsant and analgesic activity and to prevent heavy bleeding, for the synthesis of benzoxazoles with good results. The significant features of this procedure for the preparation of benzoxazoles include the use of water as a green and attractive solvent in an organic reaction, the use of ambient air as a benign sole oxidant due to its abundance, low cost, mild conditions, environmentally friendly, the use of a biodegradable catalyst, no moisture sensitivity, simple workup procedure, and simple recovery and recyclability of the catalyst without a significant decrease in activity, which all together make this approach in line with the 12 principles of green chemistry. These aforementioned features make the current approach attractive for academic research as well as industrial applications.

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“…Ascorbate promoted the degradation of B 12 in the solution. Ahmad et al ( Ahmad et al, 2017/01 ), ( Ahmadet aleng, 2014 ) described the degradation product as hydroxocobalamin, which is further rapidly degraded to products that do not elicit the vitamin functions. The degradation of cyanocobalamin to hydroxocobalamin involves the loss of the CN-group.…”

Section: Discussionmentioning

confidence: 99%

Quadruple fortification of salt for the delivery of iron, iodine, folic acid, and vitamin B12 to vulnerable populations

Modupe

Diósady

2021

Journal of Food Engineering

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A process for simultaneous delivery of iron, iodine, folic acid, and vitamin B 12 through salt as a potential and holistic approach to ameliorate anaemia and reduce maternal and infant mortality is presented. Two approaches for adding folic acid and B 12 to salt during double fortification with iron and iodine were investigated. Attempts to add both micronutrients through the iodine spray solution were unsuccessful. Hence, folic acid was added through a stabilized iodine solution, and B 12 was added through the iron premix. Four approaches used to incorporate B 12 into the iron premix were investigated: (1) co-extruding B 12 with iron, (2) spraying B 12 on the surface of the iron extrudate, (3) adding B 12 to the colour masking agent, and (4) adding B 12 to the outer coating. Of these approaches, coextrusion (1) was the best, based on the ease of production and stability of fortificants. The salt formulated with the solid iron-B 12 premix and sprayed iodine and folic acid solution contained 1000 ppm iron, 50 ppm iodine, 25 ppm folic acid, and 0.25 ppm B 12 . Over 98% of B 12 , 93% folic acid, and 94% iodine were retained after 6-month storage in the best formulation. This technology can simultaneously deliver iron, iodine, folic acid, and vitamin B 12 in a safe and stable salt enabling public health measures for improved health at a minimal additional cost.

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Effect of ascorbic acid on the photolysis of cyanocobalamin and aquocobalamin/hydroxocobalamin in aqueous solution: A kinetic study

Cited by 17 publications

References 51 publications

Visible-to-NIR-Light Activated Release: From Small Molecules to Nanomaterials

Visible-to-NIR-Light Activated Release: From Small Molecules to Nanomaterials

Use of Vitamin B₁₂ as a Nontoxic and Natural Catalyst for the Synthesis of Benzoxazoles via Catechols and Primary Amines in Water under Aerobic Oxidation

Quadruple fortification of salt for the delivery of iron, iodine, folic acid, and vitamin B12 to vulnerable populations

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Effect of ascorbic acid on the photolysis of cyanocobalamin and aquocobalamin/hydroxocobalamin in aqueous solution: A kinetic study

Cited by 17 publications

References 51 publications

Visible-to-NIR-Light Activated Release: From Small Molecules to Nanomaterials

Visible-to-NIR-Light Activated Release: From Small Molecules to Nanomaterials

Use of Vitamin B12 as a Nontoxic and Natural Catalyst for the Synthesis of Benzoxazoles via Catechols and Primary Amines in Water under Aerobic Oxidation

Quadruple fortification of salt for the delivery of iron, iodine, folic acid, and vitamin B12 to vulnerable populations

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Use of Vitamin B₁₂ as a Nontoxic and Natural Catalyst for the Synthesis of Benzoxazoles via Catechols and Primary Amines in Water under Aerobic Oxidation