Green chemistry and the ocean-based biorefinery

Green Chemistry @ MUN

Fran, Khaled (PhD 2008-2012), Yi (PhD 2011-2015) and Kelly (Engineering) wrote a perspective (short review) on the possibility of producing chemicals and new materials from ocean-sourced biomass. This has now been accepted for publication in the journal Green Chemistry.

Here is a link to the article: http://pubs.rsc.org/en/Content/ArticleLanding/2013/GC/C3GC36994C

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Broccolis – Contain Cancer Fighting Nature’s Vitamins

An example of the superfoods is the broccoli. Broccoli belongs to the cruciferous group of vegetables. Naturally, broccoli is an an excellent source of vitamins, minerals and fiber. These are elements from Nature that have been extensively studied.

Epidemiological studies provideevidence that the consumption of this vegetable protects against cancer. The protection against cancer is mainly derived from altering estrogen metabolism and antioxidant properties, enhancing detoxification, decreasing carcinogen coumpound activation, slowing tumor growth and inducing cancer cell apoptosis (death). Such attributes qualify broccoli as a superfood.

American Institute of Cancer Research estimates that a daily intake of three servings would potentially reduce cancer rates by 20%.

Broccoli contains certain chemicals that may reduce the risk of colorectal or other cancers, although it is not clear which individual compounds may be responsible for the protective effects. While research in this area continues, the best advice at this time to reduce cancer risk is to eat a wide variety of vegetables. It is reasonable to include broccoli as part of a balanced diet.

roccoli has been around for more than 2,000 years but has only been commercially grown in the United States since the 1920s. Today, more than 90% of the broccoli harvested in the United States comes from California, although it is also grown in other parts of the country.

About 2 decades ago, researchers first suggested a possible link between diets high in cruciferous vegetables (a group of plants including cauliflower, cabbage, broccoli, and Brussels sprouts)) and a lower risk of cancer. However, it was not until the 1990s that certain chemicals found in broccoli were identified as possible cancer-preventing compounds. In 1997, a study was published that noted broccoli sprouts had higher levels of one of these compounds than mature broccoli.

Broccoli is a plant in the cabbage family, whose large flower head is used as a vegetable. The word broccoli, from the Italian plural of broccolo, refers to “the flowering top of a cabbage”. Broccoli is usually boiled or steamed but may be eaten raw and has become popular as a raw vegetable in hors d’œuvre trays. The leaves may also be eaten.

Broccoli is classified in the Italica cultivar group of the species Brassica oleracea. Broccoli has large flower heads, usually green in color, arranged in a tree-like structure on branchessprouting from a thick, edible stalk. The mass of flower heads is surrounded by leaves. Broccoli most closely resembles cauliflower, which is a different cultivar group of the same species.

Broccoli was derived from cultivated leafy cole crops in the Northern Mediterranean in about the 6th century BCE. Since the Roman Empire, broccoli has been considered a uniquely valuable food among Italians. Broccoli was brought to England from Antwerp in the mid-18th century by Peter Scheemakers. Broccoli was first introduced to the United States by Italian immigrants but did not become widely known there until the 1920s

Broccoli is high in vitamin C and dietary fiber; it also contains multiple nutrients with potent anti-cancer properties, such as diindolylmethane and small amounts of selenium. A single serving provides more than 30 mg of vitamin C and a half-cup provides 52 mg of vitamin C. The 3,3′-Diindolylmethane found in broccoli is a potent modulator of theinnate immune response system with anti-viral, anti-bacterial and anti-cancer activity. Broccoli also contains the compound glucoraphanin, which can be processed into an anti-cancer compound sulforaphane, though the benefits of broccoli are greatly reduced if the vegetable is boiled. Broccoli is also an excellent source of indole-3-carbinol, a chemical which boosts DNA repair in cells and appears to block the growth of cancer cells.

Boiling broccoli reduces the levels of suspected anti-carcinogenic compounds, such as sulforaphane, with losses of 20–30% after five minutes, 40–50% after ten minutes, and 77% after thirty minutes. However, other preparation methods such as steaming,microwaving, and stir frying had no significant effect on the compounds.

Broccoli has the highest levels of carotenoids in the brassica family.[17] It is particularly rich in lutein and also provides a modest amount of beta-carotene.

A high intake of broccoli has been found to reduce the risk of aggressive prostate cancer. Broccoli consumption may also help prevent heart disease.

Broccoli sprouts are often suggested for their health benefits

Broccoli, raw (edible parts)
Nutritional value per 100 g (3.5 oz)
Energy 141 kJ (34 kcal)
Carbohydrates 6.64 g
– Sugars 1.7 g
– Dietary fiber 2.6 g
Fat 0.37 g
Protein 2.82 g
Water 89.3 g
Vitamin A equiv. 31 μg (4%)
– beta-carotene 361 μg (3%)
– lutein and zeaxanthin 1403 μg
Thiamine (vit. B1) 0.071 mg (6%)
Riboflavin (vit. B2) 0.117 mg (10%)
Niacin (vit. B3) 0.639 mg (4%)
Pantothenic acid (B5) 0.573 mg (11%)
Vitamin B6 0.175 mg (13%)
Folate (vit. B9) 63 μg (16%)
Vitamin C 89.2 mg (107%)
Vitamin E 0.78 mg (5%)
Vitamin K 101.6 μg (97%)
Calcium 47 mg (5%)
Iron 0.73 mg (6%)
Magnesium 21 mg (6%)
Manganese 0.21 mg (10%)
Phosphorus 66 mg (9%)
Potassium 316 mg (7%)
Zinc 0.41 mg (4%)
Link to USDA Database entry
Percentages are relative to
US recommendations for adults.
Source: USDA Nutrient DatabaseBroccoli is considered a good source of nutrients because it is rich in vitamin C, carotenoids (vitamin A-like substances), fiber, calcium, and folate. Broccoli is also a source of many substances called phytochemicals, or plant chemicals, that may have anticancer properties. For example, broccoli contains several compounds called isothiocyanates, including sulforaphane and indole-3-carbinol (I3C), which have been touted as possible anti-cancer agents in recent years. Early studies have shown these substances may act as anti-oxidants and may boost detoxifying enzymes in the body. Some studies have also suggested they may alter the levels of estrogen in the body, which might affect breast cancer risk.The chemical composition of broccoli and other cruciferous vegetables is complex, which makes it hard to determine which compound or combination of compounds may provide protection against cancer. Eating a wide variety of plant-based foods may be the best way to get the necessary components.

Some researchers suggest that small amounts of broccoli sprouts may protect against the risk of cancer as effectively as much larger amounts of the mature vegetable. We are not aware of any clinical studies that have been done in humans to verify this claim.

Another substance in broccoli, indole-3-carbinol (I3C), seems to alter estrogen levels and may also raise levels of protective enzymes in the body. Several studies of cancer cells growing in laboratory dishes or flasks have shown it may slow or stop the growth of breast, prostate, and other cancer cells. Some early studies in animals have shown similar results. Small studies in humans have found it may prevent the development of pre-cancerous growths in the cervix, as well as growths called papillomas in the throat. Again, larger studies are needed to find out what benefits I3C may have against cancer.

THE MOLECULES

The active molecules are Indole-3-carbinol (1H-indol-3-ylmethanol IUPAC name) and isothiocyanates (mostly sulforaphane: 1-Isothiocyanato-4-methylsulfinylbutane).

Indole-3-carbinol has a indole with a hydroxymethyl group that represents the hydrophilic group.
 Sulfurofane is a isothiocyanate, it means that it has a –N=C=S chemical group, formed by substituting sulfur for oxygen in the isocyanate group, bounded to a big alkyl chain containing a sulfinyl S=O group.

Both indole-3-carbinol and sulphoraphane derive from glucosinolates. Glucosinolates are a class of organic compounds that contain sulfur and nitrogen and are derived from glucose and an amino acid. They occur as secondary metabolites of almost all plants of the order Brassicales.

GENERAL EFFECTS ON HEALTH

I3C has been shown to have a chemopreventive action on several human cancers. The first and greatest effects concern breast and cervical estrogen-dependant cancer. Later, many researches managed to relate I3C with the prevention from colon, lung and prostate cancer too.
Given that, I3C can be considered a general protector against many kinds of neoplasy. At the same time other groups found that it could also play a role in improving Systemic Lupus Erythematosus patient conditions.

The micronutrient indole-3-carbinol: implications for disease and chemoprevention, 2000

Sulforaphane, like I3C, is useful against many types of cancer. Moreover, it has antimicrobial properties, as it appears to help eradicate Helicobacter Pylori from the stomach.

Molecular targets of dietary phenethyl isothiocyanate and sulforaphane for cancer

Magnetically recyclable magnetite-ceria (Nanocat-Fe-Ce) nanocatalyst – applications in multicomponent reactions under benign conditions

Magnetically recyclable magnetite-ceria (Nanocat-Fe-Ce) nanocatalyst – applications in multicomponent reactions under benign conditions

Green Chem., 2013, Advance Article
DOI: 10.1039/C3GC40375K, Paper
Manoj B. Gawande, Vasco D. B. Bonifacio, Rajender S. Varma, Isabel D. Nogueira, Nenad Bundaleski, C. Amjad A. Ghumman, Orlando M. N. D. Teodoro, Paula S. Branco
Sustainable protocol provides functionalized 1,4-dihydropyrines and tetrahydropyridine using recyclable nano-catalyst.

A novel magnetite nanoparticle-supported ceria catalyst (Nanocat-Fe-Ce) has been successfully prepared by a simple impregnation method and was characterized by XRD, SIMS, FEG-SEM-EDS, and TEM. The exact nature of Nanocat-Fe-Ce was confirmed by X-ray photoelectron spectroscopy and it is noted that CeO2 nanoparticles are supported on magnetite, with evidence of secondary ion mass spectrometry. Catalytic activity of the nano-catalyst was explored for the synthesis of dihydropyridines under benign conditions; a greener protocol is described that provides a simple and efficient method for the synthesis of functionalized 1,4-dihydropyridines using a recyclable nanocatalyst. Notably, 5.22 mol% of the catalyst is sufficient to catalyze the multicomponent reaction in ethanolic medium at room temperature. Importantly, the catalyst could be easily separated from the reaction mixture by using an external magnet and recycled several times without loss of activity.

 

From Biomass to Commodity Chemicals

GreenChemBlog

“An efficient didehydroxylation method for the biomass-derived polyols glycerol and erythritol.  Mechanistic studies of a formic acid-mediated deoxygenation” Arceo, E.; Marsden, P.; Bergman, R. G.; Ellman, J. A.Chemical Communications, 2009, 23, 3357. 10.1039/b907746d

A major focus in the area of “green” methods development is the mild and selective removal of functionality from readily available bio-derived feed stocks.  Unlike petrochemical derived starting materials, the majority of biomass is highly oxygenated (think carbohydrates or lignin), and before the carbon embedded within this framework can be used for all-purpose chemical manufacturing the oxygen must be removed.

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Green Chemistry on your Smart Phone!

GreenChemBlog

“Incorporating Green Chemistry Concepts into Mobile Chemistry Applications and Their Potential Uses.” Ekins, S.; Clark, A. M.; Williams, A. J. ACS Sustainable Chem. Eng.2013, 1, 8-13. DOI: 10.1021/sc3000509

We here at GreenChemBlog have not posted in a while, but still hope to post and are still looking for contributors to the blog. Posts might be a bit shorter going forward, though, in order for us to post more frequently.

I’ve expanded my reading recently to include a new ACS journal, ACS Sustainable Chemistry & Engineering. In the first issue is the above article, which highlights a few recent additions to the smart phone/tablet world that utilize green chemistry!

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We have joined Science without Borders

mcgarrigleresearch

UCD has joined the Science without Borders‘/’Ciênca sem Fronteiras scheme. We are now seeking interested applicants from Brazil under this scheme. These PhD opportunities are listed in the ‘Current PhD Opportunities’ of the UCD ‘Science without Borders website along with further details of the scheme. Interested applicants from Brazil are invited to contact Eoghan by email.

Please see our PhD vacancies page for other PhD opportunities.

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Hydrolysis of cellulose to glucose by solid acid catalysts

Graphical abstract: Hydrolysis of cellulose to glucose by solid acid catalysts

This paper reviews the recent advances in cellulose hydrolysis into glucose over solid acids, which plays an important role in the conversion of biomass derived carbohydrates into useful platform molecules.

As the main component of lignocelluloses, cellulose is a biopolymer consisting of many glucose units connected through β-1,4-glycosidic bonds. Breakage of the β-1,4-glycosidic bonds by acids leads to the hydrolysis of cellulose polymers, resulting in the sugar molecule glucose or oligosaccharides. Mineral acids, such as HCl and H2SO4, have been used in the hydrolysis of cellulose. However, they suffer from problems of product separation, reactor corrosion, poor catalyst recyclability and the need for treatment of waste effluent. The use of heterogeneous solid acids can solve some of these problems through the ease of product separation and good catalyst recyclability. This review summarizes recent advances in the hydrolysis of cellulose by different types of solid acids, such as sulfonated carbonaceous based acids, polymer based acids and magnetic solid acids. The acid strength, acid site density, adsorption of the substance and micropores of the solid material are all key factors for effective hydrolysis processes. Methods used to promote reaction efficiency such as the pretreatment of cellulose to reduce its crystallinity and the use of ionic liquids or microwave irradiation to improve the reaction rate are also discussed.

link

Yao-Bing Huang and Yao Fu
Affiliation Information
1. Department of Chemistry,Anhui Province Key Laboratory of Biomass Clean Energy,University of Science and Technology of China, Hefei 230026, P. R. China
Green Chem., 2013, Advance Article

DOI: 10.1039/C3GC40136G

http://pubs.rsc.org/en/Content/ArticleLanding/2013/GC/C3GC40136G?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29