NaturAsia

I have written about gold many times. There was golden sesame in Japanese gomasio , golden honey coloured sesame oil, Ghee – the liquid gold, turmeric – a spice more precious than gold, soon I will also be writing about (real) gold in cosmetics.

The popularity of both the metal and the colour is as great and constant as fascination with the sun, the source of golden light, light and life dating back thousands of years.

So here’s another product, the name of which, golden milk, comes from the golden light of the sun and its soothing qualities.

While Ayurveda recommends drinking milk, as a holy, precious and irreplaceable food (of course we are talking about real milk from real cows, not out of a box), it does not recommend drinking it without prior preparation. In the West, the
widespread and unquestioning focus on milk as a source of protein and calcium, assisting in the prevention of…

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The Bingel reaction in fullerene chemistry

Bingel fullerene

The Bingel reaction in fullerene chemistry

The Bingel reaction in fullerene chemistry is a fullerene cyclopropanation reaction to a methanofullerene first discovered by C. Bingel in 1993 with the bromo derivative of diethyl malonate in the presence of a base such as sodium hydride or DBU.^[1] The preferred double bonds for this reaction on the fullerene surface are the shorter bonds at the junctions of two hexagons (6-6 bonds) and the driving force is relief of steric strain.

The reaction is of importance in the field of chemistry because it allows the introduction of useful extensions to the fullerene sphere. These extensions alter their properties for instance solubility and electrochemical behavior and therefore widen the range of potential technical applications.

Bingel reaction mechanism: E strong electron withdrawing group, L leaving group

The reaction mechanism for this reaction is as follows: a base abstracts the acidic malonate proton generating a carbanion or enolatewhich reacts with the electron deficient fullerene double bond in a nucleophilic addition. This in turn generates a carbanion which displaces bromine in a nucleophilic aliphatic substitution in an intramolecular ring cyclopropane ring closure.

The Bingel reaction is a popular method in fullerene chemistry. The malonate (functionalized with the halide atom) is often obtained in situ in a mixture of base and tetrachloromethane or iodine.^[2] The reaction is also known to take place with the ester groups replaced byalkyne groups in dialkynylmethanofullerenes.^[2]

Bingel reaction of fullerene with a malonate ester and a) sodium hydride or DBUin toluene at room temperature 45% yield.

An alternative to the Bingel reaction is a fullerene diazomethane reaction. N-(Diphenylmethylene) glycinate Esters ^[3] in a Bingel reaction take a different conjugate course and react to a fullerene dihydropyrrole.

Bingel reaction with N-(Diphenylmethylene)glycinate Ester

1.  Bingel, Carsten (1993). “Cyclopropanierung von Fullerenen”. Chemische Berichte126 (8): 1957. doi:10.1002/cber.19931260829.
2. Yosuke Nakamura, Masato Suzuki, Yumi Imai, and Jun Nishimura (2004). “16”. Org. Lett.6 (16): 2797–2799.doi:10.1021/ol048952n. PMID15281772.
3. Graham E. Ball, Glenn A. Burley, Leila Chaker, Bill C. Hawkins, James R. Williams, Paul A. Keller, and Stephen G. Pyne (2005). “Structural Reassignment of the Mono- and Bis-Addition Products from the Addition Reactions of N-(Diphenylmethylene)glycinate Esters to [60]Fullerene under Bingel Conditions”. J. Org. Chem.70 (21): 8572–8574. doi:10.1021/jo051282u. PMID16209611.
4. Kessinger, Roland; Crassous, Jeanne; Herrmann, Andreas; Rüttimann, Markus; Echegoyen, Luis; Diederich, François (1998). “Preparation of Enantiomerically Pure C76 with a General Electrochemical Method for the Removal of Di(alkoxycarbonyl)methano Bridges from Methanofullerenes: The Retro-Bingel Reaction”. Angewandte Chemie International Edition37 (13-14): 1919.doi:10.1002/(SICI)1521-3773(19980803)37:13/14<1919::AID-ANIE1919>3.0.CO;2-X.
5. Herranz, M. ÁNgeles; Cox, Charles T.; Echegoyen, Luis (2003). “Retrocyclopropanation Reactions of Fullerenes:  Complete Product Analyses”. The Journal of Organic Chemistry68 (12): 5009. doi:10.1021/jo034102u. PMID12790625.
6. Moonen, Nicolle N. P.; Thilgen, Carlo; Diederich, François; Echegoyen, Luis (2000). “The chemical retro-Bingel reaction: selective removal of bis(alkoxycarbonyl)methano addends from C60 and C70 with amalgamated magnesium”. Chemical Communications (5): 335. doi:10.1039/a909704j.

Protocols exist for the removal of the methano group based, on electrolytic reduction ^[4][5] or amalgamated magnesium ^[6]

 

The Chemistry of Love

There are a lot of chemicals racing around your brain and body when you’re in love. Researchers are gradually learning more and more about the roles they play both when we are falling in love and when we’re in long-term relationships. Of course, estrogen and testosterone play a role in the sex drive area . Without them, we might never venture into the “real love” arena.

That initial giddiness that comes when we’re first falling in love includes a racing heart, flushed skin and sweaty palms. Researchers say this is due to the dopamine, norepinephrine and phenylethylamine we’re releasing. Dopamine is thought to be the “pleasure chemical,” producing a feeling of bliss. Norepinephrine is similar to adrenaline and produces the racing heart and excitement. According to Helen Fisher, anthropologist and well-known love researcher from Rutgers University, together these two chemicals produce elation, intense energy, sleeplessness, craving, loss of appetite and focused attention. She also says, “The human body releases the cocktail of love rapture only when certain conditions are met and … men more readily produce it than women, because of their more visual nature.”

Researchers are using functional magnetic resonance imaging (fMRI) to watch people’s brains when they look at a photograph of their object of affection. According to Helen Fisher, a well-known love researcher and an anthropologist at Rutgers University, what they see in those scans during that “crazed, can’t-think-of-anything-but stage of romance” — the attraction stage — is the biological drive to focus on one person. The scans showed increased blood flow in areas of the brain with high concentrations of receptors for dopamine — associated with states of euphoria, craving and addiction. High levels of dopamine are also associated with norepinephrine, which heightens attention, short-term memory, hyperactivity, sleeplessness and goal-oriented behavior. In other words, couples in this stage of love focus intently on the relationship and often on little else.

Another possible explanation for the intense focus and idealizing view that occurs in the attraction stage comes from researchers at University College London. They discovered that people in love have lower levels of serotonin and also that neural circuits associated with the way we assess others are suppressed. These lower serotonin levels are the same as those found in people with obsessive-compulsive disorders, possibly explaining why those in love “obsess” about their partner.

 

 

Sunitinib Benefits Patients With Renal Cell Carcinoma

sunitinib

Sunitinib (marketed as Sutent by Pfizer, and previously known as SU11248) is an oral, small-molecule, multi-targeted receptor tyrosine kinase (RTK) inhibitor that was approved by the FDA for the treatment of renal cell carcinoma (RCC) and imatinib-resistant gastrointestinal stromal tumor (GIST) on January 26, 2006. Sunitinib was the first cancer drug simultaneously approved for two different indications.^[1]

Feb. 8, 2013 — Findings from clinical trial patients with metastatic renal cell carcinoma, a common kidney cancer, show they did not have accelerated tumor growth after treatment with sunitinib, in contrast to some study results in animals. Sunitinib is one of several drugs, either on the market or undergoing testing, that target blood vessel growth. There had been debate, based on the animal studies, about whether tumor blood vessel changes induced by these drugs promoted tumor growth and/or caused cancer to spread. In this study, Tito Fojo, M.D., Ph.D., head of the Experimental Therapeutics Section, Medical Oncology Branch and Affiliates, NCI, and his colleagues, found that not to be the case.

Results of their study appeared in Cell Reports, Feb. 7, 2013.

http://www.cell.com/cell-reports/abstract/S2211-1247%2813%2900022-3?switch=standard

doi:10.1016/j.celrep.2013.01.015

Using a mouse model to assess small, relatively newly developed tumors can be much more challenging than assessment in humans who tend to have more established tumors several centimeters in size. To address whether sunitinib accelerated tumor growth in humans, researchers analyzed data from a randomized phase III trial comparing sunitinib with interferon alfa in patients with kidney cancer. Using a novel methodology for assessing efficacy , they found sunitinib reduced the tumor’s growth rate while improving survival, without appearing to negatively alter tumor biology after discontinuation.

Their findings suggest that concerns arising from animal models may not apply to patients receiving sunitinib and most likely will not apply to patients using similar agents, but recognize more studies may need to be done.

SUTENT, an oral multi-kinase inhibitor, is the malate salt of sunitinib. Sunitinib malate is described chemically as Butanedioic acid, hydroxy-, (2S)-, compound with N-[2-(diethylamino)ethyl]-5-[(Z)-(5-fluoro- 1,2-dihydro-2-oxo-3H-indol-3-ylidine)methyl]-2,4-dimethyl-1H-pyrrole-3-carboxamide (1:1). The molecular formula is C₂₂H₂₇FN₄O₂ • C₄H₆O₅ and the molecular weight is 532.6 Daltons.

The chemical structure of sunitinib malate is:

Sunitinib malate is a yellow to orange powder with a pKa of 8.95. The solubility of sunitinib malate in aqueous media over the range pH 1.2 to pH 6.8 is in excess of 25 mg/mL. The log of the distribution coefficient (octanol/water) at pH 7 is 5.2.

SUTENT (sunitinib malate) capsules are supplied as printed hard shell capsules containing sunitinib malate equivalent to 12.5 mg, 25 mg or 50 mg of sunitinib together with mannitol, croscarmellose sodium, povidone (K-25) and magnesium stearate as inactive ingredients.

The orange gelatin capsule shells contain titanium dioxide, and red iron oxide. The caramel gelatin capsule shells contain titanium dioxide, red iron oxide, yellow iron oxide and black iron oxide. The white printing ink contains shellac, propylene glycol, sodium hydroxide, povidone and titanium dioxide.

http://www.cell.com/cell-reports/abstract/S2211-1247%2813%2900022-3?switch=standard