2- hydroxypropyl phosphate

In the second model system 3.28 [56], a proton inventory study indicates that the guanidinium group is involved in hydrolysis as a general acid, rather than simply affording electrostatic stabilization of the phosphorane dianion. The nucleophilic part of the reaction, the cyclization of the 2-hydroxypropyl phosphate, is much less efficient than for 3.25, and the leaving group is a phenol so the rate determining step will be the formation of the phosphorane, as shown (3.28, Scheme 2.28). 

Starch phosphates have been oxidized to carboxylic derivatives.1622 Starches oxidized by NaOCl could be phosphorylated with POCI3,1623 causing crosslinking. The reaction of starch phosphate with glycidyltrimethylammonium chloride gave the corresponding phosphobetaine compound, starch poly[3-(lV,lV,lV-trimethylammonio)-2-hydroxypropyl phosphate].1624... 

Alternatively, the use of starting materials with the hydrophobic chain on the amine allows it to become the coupling group [83-86]. Typically, sodium dihydrogen phosphate is condensed in an aqueous enviromnent with epichlorohydrin. The reaction is carried out at 30-50% solids at a pH of 4-5 at 80-85°C. The sodium 3-chloro-2-hydroxypropyl phosphate intermediate (see sequence in the following structure) is further reacted with a tertiary amine or amidoamine. 

A DFT study of the cleavage of a DNA model, p-nitrophenyl methyl phosphate (47), and two RNA models, p-nitrophenyl 2-hydroxypropyl phosphate (48) and phenyl 2-hydroxypropyl phosphate (48 H for NO2), promoted by the dinuclear Zn(II) complex of l,3-bis(l,5,9-triazacyclododec-l-yl)propane formulated with a bridging methoxide (49), was undertaken to determine possible mechanisms for the tfansesterification processes that are consistent with experimental data. The initial substrate-bound state of... 

The reaction between hydroxypropyl phosphate and dicyclohexyl carbodiimide in aqueous pyridine leads to 2-hydroxy-l,3,2 dioxaphosphinane 2 oxide, which if isolated and reacted further under anhydrous conditions, gives 2,2 oxybis-(l,3,2 dioxaphosphinane 2,2 oxide) (6.940) which is a diphosphate. 

Finally, Colonial Chanical has introduced anionic Suga Phos surfactants, marketed as a gemini surfactant with mild properties for use in personal care applications [110]. The surfactants (Figure 29.29) are apparently produced by linking alkylpolyglucosides with a hydroxypropyl phosphate spacer via a chlorohydroxypropyl phosphate intermediate. 

Derivatized Acetyl Hydroxypropyl Phosphate Stable at freeze-thawing cycles Canned and frozen food... 

Hydroxypropyl cellulose Creatinol phosphate Creatinolfosfate m-Cresol... 

To circumvent these difficulties, a preparation of water-soluble coelenterazine has been developed (Teranishi and Shimomura, 1997a). The preparation contains coelenterazine and 50-times (by weight) of hydroxypropyl-P-cyclodextrin. To prepare this material, 0.1 ml of 3.0 mM coelenterazine in methanol and 0.2 ml of 45 mM solution of the cyclodextrin are mixed and dried under reduced pressure. The dried residue is extracted with 1.0 ml of lOmM phosphate buffer, pH 7.0, containing 2 mM EDTA (if needed), and the extract (after centrifugation) is again dried under reduced pressure. With this preparation, an aqueous solution containing up to 3 mM coelenterazine can be made. 

Pregelatinized starch Hydroxypropyl cellulose Calcium phosphate... 

Suspension of water soluble solids in oil can be achieved by a variety of chemical additives. Chemical suspension additives that have been suggested include alkyl mercaptophosphonic acids(174), organophylic clay plus hydroxypropyl cellulose(175), polyols(176), aluminum stearate(177), organophylic clay plus surfactant(178-181), aluminum phosphate esters(182), and acrylate copolymers(183-184). 

Compound 10 has also been used to quantify double Lewis acid activation by two cobalt (HI) ions [37]. In 12, the RNA analogue 2-hydroxypropyl-phenyl phosphate (HPPP) is coordinated to the dinu-clear cobalt site. It is well known that in this substrate the hydroxypropyl group is an efficient intramolecular nucleophile. Release of phenol by intramolecular cyclization is much faster than the reaction by nucleophilic attack of bridging oxide, as observed in 11. At pH >8, transesterification rate is linearly dependent on hydroxide concentration since OH" acts as an intermolecular base for the deprotonation of the hydroxypropyl group. The second order rate constant for the hydroxide-dependent cleavage is 4 x 105 times larger than the second-order rate constant for the hydroxide-dependent spontaneous transesterification of hy-droxypropyl-phenyl phosphate. 

In spite of the above mentioned Co(EII) compounds, kinetically labile metal complexes may provide fast product/substrate exchange and some of these systems show real catalytic activity. In native dinuclear phosphatases Mg(II), Mn(II), Fe(II/III), or Zn(II) ions are present in the active centers. Although the aqua complexes of the weakest Lewis acids, Mg(H) and Mn(II), show measurable acceleration of e.g. the transesterification of 2-hydroxypropyl p-nitrophenyl phosphate HPNP, [Mn(II)] = 0.004 M, kobs/ uncat = 73 at pH 7 and 310 K, [38] or the hydrolysis of S -uridyluridine (UpU) [39], only a few structural [40] but no functional phosphatase-mimicking dinuclear complexes have been reported with these metal ions. 

Diester methods have been used to synthesize analogues of the initiator codon ApUpG in which the adenine residue has a fixed torsion angle, as for instance in (78),132 and triester methods have been used to prepare dinucleoside phosphates and codon analogues133 134 containing the hydroxyalkyl nucleosides 9-(4 -hydroxybutyl)-adenine (80), 9-(3 -hydroxypropyl)adenine (81), and 1 -(3 -hydroxypropyl)uracil (82), with a view to determining the effect of the achiral residues on the c.d. spectra. 

Excipients Cellulose, disodium hydrogen phosphate, hydroxypropyl cellulose, hydroxypropyl methylcellulose, lactose, mannitol, sodium lauryl sulfate, etc. 

Dual modification Acetylated distarch phosphate - Esterification by sodium trimetaphosphate or phosphorus oxychloride combined with esterification by acetic anhydride or vinyl acetate Hydroxypropyl distarch phosphate - Esterification by sodium trimetaphosphate or phosphorus oxychloride combined with etherification by propylene oxide... 

Wu, Y, Seib, P. A. (1990). Acetylated and hydroxypropylated distarch phosphates from waxy barley paste properties and freeze-thaw stability. Cereal Chem., 67, 202-208. 

Sulfonated styrene, maleic anhydride (SS/MA) has proved to be a popular inhibitor for calcium phosphate control in stabilized phosphate and other polyphosphate programs. As such, it competes with other calcium phosphate control technologies, such as acrylic acid, hydroxypropyl acrylate copolymer (AA/HPA) and acrylic acid, 2-acrylimido-2-methylpropanesulfonic acid (AA/AMPS, or sometimes known as AA/SA), and acrylic acid, sodium 3-allyloxy-2-hydroxypropane sulfonate copolymer (AA/COPS). 

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