No Added Chemicals

... One of the metabolic processes is called citric acid cycle (CAC) or famously known as Krebs cycle; named after its discoverer Hans Krebs. Hans Krebs himself was awarded Nobel Prize in Physiology or Medicine in 1953... In part I, we decoded half of the Krebs cycle as citrate ion (6C) is converted to succinyl-CoA (4C) after several steps. Afterwards, in succinyl coenzyme synthetase (CSC) succinate (4C) is formed from succinyl-CoA (4C) with helps of either GDP or ADP.

Hans Krebs The way living things can maintain its function, do many activities, or just simply to survive in this harsh world sometimes can be mysterious. However, there is one way to understand these mysterious processes and science, especially chemical science, can help us to understand these processes. These processes are sometimes metabolic processes and it can be seen as chemical reactions that happen in living things, from bacteria to blue whale. One of the metabolic processes is called citric acid cycle (CAC) or famously named Krebs cycle; named after its discoverer Hans Krebs. Hans Krebs himself was awarded Nobel Prize in Physiology or Medicine in 1953.

Amide is one of the organic functional groups that can be found ubiquitously in the nature. It plays important role in living things as the main building blocks of proteins which involve with many functions, from catalysis to structural support. Besides that, amide functionality is featured in many natural products and drugs. Examples of peptide-bearing compounds Since, it is quite common to find this functionality in natural products and synthetic compounds, a question is raised from this phenomenon. How trivial is it to make amide bond?

25.7 MW Lauingen Energy Park, Germany As part of solutions for the climate change, the demand for 'clean' energy has increased in the recent years. One of the piece of technologies that can fulfil this demand is solar cell which it can harness the solar energy. At this stage, the conventional solar cell, which is made of a thick layer of doped-silicon, is very expensive and the manufacturing process is energy consuming process. Another type of solar cell, dye sensitised solar cell (DSSC) or Grätzell cell, can be a solution for the expensive silicon solar cell. Instead of expensive silicon as semiconductor, cheaper TiO 2 is used and ruthenium-based complex compound as solar light harvester. However, this cell has a problem with solvent leakage, which can be  not environmentally friendly. The efficiency of this cell is also a problem; DSSC's efficiency is up to 11% while Si-based solar cell can be up to 25%. To address these problems, another type of solar cell has been ...

In the recent decade, chemists have taken nature as its inspiration in many ways; one of them is in medicinal chemistry. Many natural products have been screened for their bioactivities to develop new generation of therapeutic agents for 'incurable' diseases such as cancer. However, there is one major drawback from taking natural product as drug. This problem is its complex structure which makes it difficult to synthesise especially in large scale. Anticancer drugs: natural products (paclitaxel) and coordination complex (cisplatin) Luckily, a simple coordination complex, such as cisplatin, gives similar efficacy as natural product-based drug and simple coordination complex is used to treat 80% of all solid cancers. It is noteworthy that the market for this drug is around $1 billion.

In these days, the chemistry of natural products is still a massive attraction for chemists, especially organic synthetic chemists. New substances, more or less complicated, more or less useful, are constantly discovered and investigated with all the techniques and tools that the early organic chemists could only imagine. In the course of these studies, the researchers are challenged by the preparation of the compounds which somehow drives this field forward. This time, we'll see the historical perspective of this 'ancient' research field and also future prospective that chemistry of natural products can offer.

This time, it is less than a week until Christmas and it is quite appropriate if this time we are digging one of the stories around Christmas, which is the adoration of the magi. The magi, sometimes they are called the wise men or kings, travelled from far east to Bethlehem following the Star of Bethlehem to pay homage to the Infant Jesus. They also brought three gifts to be given to the King of kings: gold, frankincense, and myrrh. This story and the gifts they brought are immortalised in several Christmas carols, one of them is  "We Three Kings " by John Henry Hopkins. We Three Kings  arr. Martin Neary and sung by King's College Choir at 2012 Festival of Nine Lessons and Carols. For lyrics, click here . This time, for Christmas special, we'll see the chemical significance of those gifts for the Infant Jesus.

Chemical synthesis has become a great tool in exploring interesting structures such as natural products. However, this is not only limited into the natural products, the ultimate designed in miniaturisation can also be attained such as nanocar . Researchers from Houston, USA successfully created a new class of 2 nm-tall human-like, anthromorphic, compounds. This class of compound is dubbed as NanoPutians, after Liliputians from Jonathan Swift's classic Gulliver's Travel. The first edition of Jonathan Swift's Gulliver's Travel  

Bartlett's oxidation of Xe using PtF 6   The noble gas compounds have been a great interest since the creation of its kind, XePtF 6 , in 1962. Since then, many xenon compounds with direct bonds to fluorine, oxygen, nitrogen, carbon, xenon itself, and chlorine have been established. However, all these bonded atoms are electronegative main-group elements but there have been several indications that metal-xenon bonds can be formed and detected such as (CO) 5 Mo...Xe. Besides that, The Au-Xe + has been detected by mass spectroscopy and has been calculated with a best estimate for the bond distance of 257 pm. Researchers from Germany successfully created the first metal-xenon square planar compound with direct Au-Xe bond.

It was isolated for the first time in 1966 from the plant Rhazya stricta , strictamine (1)  has been a great interest due to its unique properties. Strictamine belongs to the group of akuammiline alkaloids which is the family of monoterpenoid indole alkaloids. This compound has been showed to inhibit the nuclear factor-𝜅B (NF-𝜅B), which plays an important role in immune and inflammatory responses. Apart from its bioactivity, strictamine has attracted synthetic chemists because its structure bearing a tricyclic unit of methanoquinolizidine. This interesting challenge causes only four groups - Garg (enantioselective), Zhu (racemic), Ohno (formal synthesis), and Gaich (formal synthesis) - have managed to complete a total synthesis of strictamine. This time on " Totally Synthesised" , we will see synthetic strategy by Gaich's group which used [2,3]-Stevens rearrangement to build the methanoquinolizidine unit.

In nature, self-assembly has been exploited in many ways to create molecular systems for biological processes. This idea has inspired many chemists in recent decade to use self-assembly to access various function of molecular level. However, there is a major difference between the synthetic and natural self-assembled systems. The synthetic self-assembly produces the most thermodynamically stable product. On the other hand, many natural self-assembly processes are energetically uphill and require a continuous consumption of energy to maintain its structure; this is referred as dissipative self assembly. The formation and dissociation of actin filament, one of the example dissipative self-assembly. (J. Baum, A. T. Papenfuss, B. Baum, T. P. Speed, and A. F. Cowman, Nature Rev. Microbiol. , 2006, 4 , 621-628) Recently, researchers from University of Padova successfully found a novel strategy for the dissipative vesicular structure that are stable to maintain its shape in the present ...

In biological process, molecular machines are one of the examples of the most intricate functional molecules and have been attracted many chemists recently. Inspired from this idea, synthetic molecular machines have been developed ranging from synthesizers to motors, but there are no synthetic molecule machines that operate autonomously using chemical energy; in biological process ATP is used as the chemical energy or fuel. One of the example of motor protein: ATP synthase. (J. Weber, Nat. Chem. Biol. , 2010, 6  794-795) Leigh's group from the University of Manchester successfully created a system in which small molecular ring is transported around a cyclic molecular track when powered by irreversible reaction.

Single-walled carbon nanotubes (SWNTs) has been a great interest due to their unique properties and those have motivated researchers to investigate their use in variety of application such as electrostatic discharge, structural reinforcement, and thermal dissipation. However, SWNT has main weakness that hinders the development of its application which is poor solubility and processibility. Many processing techniques and modification on the surface of nanotubes, either covalently or noncovalently, have been developed. Scanning tunnelling microscopy image of nanotubes. (T. W. Odom, J.-L. Huang, and C. M. Lieber, J. Phys.: Condens. Matter , 2002, 14 , R145-R167). Taton's group from University of Minnesota developed a way to encapsulate carbon nanotubes using crosslinked, amphiphilic copolymer micelles.

The ability of nanoparticles to self-assemble forming larger structures is determined by the details of the forces between particles. This mean of interaction has led to novel concepts in self-assembly such as in colloids and Janus particles (type of nanoparticles with two or more physical properties of its surface). Recently, some models that include attractive region or 'patches' on the surface of nanoparticles have been made and predict intricate modes of assembly and these interactions are also important in a range of phenomena including protein aggregation and crystallisation. Example of Janus particles (accessed http://www.pi2.uni-stuttgart.de/cms/index.php?article_id=156) Meijer's group Eindhoven University of Technology successfully synthesised 6-nm nanoparticles with dynamic hydrophobic patches and it can self-assemble reversibly in water.

The generosity of mother nature is limitless and it will not stop giving for humankind to thrive. Besides that, nature has been a close friend with chemists especially organic chemists. Complex structures of natural products have been a great interest as it provides to develop synthetic methods to synthesise natural products. One of the 'hunting grounds' of synthetic organic chemists is the sea, and one of the products is called eleutherobin, 1 . Eleutherobin can be isolated form a species of marine soft corals Eleutherobia  collected in the Indian Ocean near Bennett's Shoal in Western Australia. Despite its rarity, eleutherobin is a potent compound against selected breast, renal, ovarian, and lung cancer cells. This highly potential compound drove Nicolaou's group to synthesise this compound.

Machinery has propelled human civilisation into another level by helping us to perform tasks beyond our capability. In decades, human has made different type of machines with various of sizes; from enormous machine into molecular-size machinery. The ideas of molecular-size machinery are inspired from the nature in the cellular level such as ATP synthase motor and kinesin transporter. ATP synthase motor (right, J. Weber, Nat. Chem. Biol. , 2010, 6 , 794-795) and Feringa's nanocar (left, ©Johan Jarnestad/The Royal Swedish Academy of Sciences) One of the prominent examples of the molecular machines is Feringa's nanocar  where the molecule is propelled by four rotating molecular motors.

The synthesis of supramolecules has become an intense interest in the recent years, especially conjugated π-system. In the previous post , a cyclic octamer of porphyrin was synthesised and it gives optical interesting properties. Increasing its dimensionality, such as into barrel-like structure, could enhance electronic delocalisation and perhaps leading to exotic properties such as Aharonov-Bohm oscillation. This property has been observed in single-walled nanotubes (SWNTs) but it hasn't yet been detected in molecular materials, so this gives motivation for synthetic chemist to synthesise the molecular SWNT to observe this exotic property. Anderson's group from Oxford University successfully synthesised porphyrin tube 1  which consists of 12 porphyrins, each of which is directly conjugated to its three neighbours.

The Royal Swedish Academy of Sciences  has decided to award the Nobel Prize in Chemistry 2016 to \ Jean-Pierre Sauvage (University of Strasbourg, France) Sir J. Fraser Stoddart (Northwestern University, Evanston, IL, USA) Bernard L. Feringa (University of Groningen, the Netherlands) "for the design and synthesis of molecular machines"

Chemical physicist and spectroscopist C. K. Jørgensen once said that one of the major goals of inorganic chemistry is to prepare compounds of elements in unusual oxidation states. In 2009, the range of oxidation states produced from chemical reaction was -4 to +8, and in 2010 Himmel's group showed that Ir compound with +9 oxidation state, [IrO 4 ] + , exists by electronic structure calculations. In 2014, Wang's group confirmed the existence of the Ir(IX) by matrix-isolation experiments. From these ideas, can it be stretched further? Let say oxidation state +10?

The secondary structures of proteins, such as α-helices, β-sheets, or β- or γ-turns, mainly determine the overall 3-dimensional structures of protein and these structures are mainly stabilised by interactions such as hydrogen bonding (H-bonding) and dispersion interactions. Besides that, the interaction with its biological environment also contributes to the overall structure which means the intrinsic properties of the protein are hidden. Therefore, to have a better understanding about protein structure, proteins or polypeptides must be in isolated condition where no solvent molecules are present. One of the methods that can be used to study peptides in this isolated is gas-phase spectroscopy. 3D structure of myoglobin with α-helices and random coils are shown