SMARTS chirality

Many structure variations of PHA have also been synthesized. Due to the small number of these uneonventional PHA, Uttle physieal eharacterization and application research has been carried out so far. By reviewing the PHA research carried out to date, it is clear that many works have been directed towards the design, biosynthesis, and properties of biodegradable and biocompatible materials, these materials ean be explored for bioengineering new optical and other smart chiral materials. Additionally, the funetional groups of these unconventional PHA provide a lot of opportunities for further chemical modifications. 

Using simple rules, a structure is represented by a string of characters unique to that structure. It can also be used to specify stereochemistry at double bonds and chiral centres. SMARTS is a further extension that allows substructure searching. 

Usnally a nncleic acid probe that emits a signal only when bound to a specific target. An example is a molecular beacon. See Stohr, K., Hafner, B., Nolle., O. et al.. Species-specific identification of mycobacterial 16S rRNA PCR amplicons nsing smart probes. Anal. Chem. 77, 7195-7203, 2005. There are other examples of smart probes inclnding proteins (Wunder, A., Tung, C.-H., Mtiller-Ladner, U., Weissleder, R., and Mahmood, U., In vivo imaging of protease activity in arthritis, a novel approach for monitoring treatment response, Arthritis Rheumatism 50, 2459-2465, 2004) and chiral compounds (Tsukube, H. and Shinoda, S., Lanthanide complexes as smart... 

CD probes for chirality sensing of biological substrates, Enantiomer 5, 13-22, 2000). Smart contrast reagents have also been developed for magnetic resonance stndies (Lowe, M.R, Activated MR contrast reagents, Curr. Pharm. Biotechnol. 5, 519-528, 2004). 

The area of (chiral) MO-oligodentate ligand synthesis - see, for example, the known Structures 4-6 - also merits future attention. Smart ideas are required because these ligands become more and more sophisticated [34]. Logically, yV/(9-ligands are more resistant to oxidation than phosphines, one of the reasons... 

Among the different possible methodologies available, the use of a chiral catalyst represents, in principle, the most attractive procedure to synthesize enantiomerically enriched compounds, since in a catalytic process a small amount of a smart molecule produces a large quantity of the desired chiral compound [ ] ... 

It is possible to represent chirality in SMILES. This is essential to correctly define the appropriate enantiomer or stereoisomer. Many databases will contain isomers. It is possible to relate the various isomers of a structure by using their common canonical SMILES. This might be done by relaxing the uniqueness constraint on the cansmi column in a structure table, or by adding another table of stereoisomers that is related to the master table. Chirality may be used in SMARTS as well. 

Another interesting technique to solve the problem of mass transport in bipha-sic reactions was developed by Fell and Jin, the catalysis with so-called thermo-regulated phase transfer ligands [177-185] (details see Section 4.6.3). In the examples given so far, a smart solvent system controlled the phase behaviour of the reaction mixture. Lemaire et al. have found that also polyether-functionalized chiral mono- or diphosphites are active in thermoregulated conversion [186]. The hy-droformylation of styrene yields conversions of 99%, n/i-ratios of 85/15 and an enantioselectivity of up to 25%. A recycling of the catalyst proved to be possible, however, with a certain leaching of the rhodium catalyst. 

Marissen, R., Duurkoop, D., Hoefnagels, H., Bergsma, O. K. Creep forming of high strength polyethylene fibre prepregs for the production of ballistic protection helmets. Composites Science and Technology 2010 70(7) 1184-8 (Special issue on Chiral Smart Honeycombs). 

Qing, G. Sun, T. Chirality-triggered wettability switching on a smart polymer surface. Adv. Mater. 2011,23, 1615-1620. 

Polyhydroxyalkanoates (PHA) is a family of structurally diverse biopolyesters accumulated by many bacteria as carbon and energy source (Figure 16.1)d PHA have been exploited with a series of applications including environmentally friendly biodegradable plastics for packaging purposes, biofuels, medical implants, and recently, smart materials. PHA monomers are also produced as chiral intermediates for medical or fine chemical applications. ... 

We would like to close this section with some remarks, in particular concerning the different order parameters. First of all we note a surprising thing about the very smart Pikin-Indenbom order parameter. It has been very important in the basic symmetry discussion, but it has never really been used as such in practice. Perhaps because it is too sophisticated in its simplicity. Everybody instead uses the tilt vector as order parameter. But = 1 2) is non-chiral, hence... 

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