Inositols 0-methyl

Quebrachitol (Quebrachite, Methoxy pinite, /-Inositol methyl ether, Bomesitol). C6H6(OH)5.OCH3, raw 194.18, mp 190-94°, bp 210° at 6 mm, crystallizes well from acet. Was first obtained by Tanret (Ref 2) from quebrache by a series of operations, also described in Beilstein (Ref 1, p 1193). A, DeJong... 

Recently, it has been reported101 that mt/o-inositol reacts rapidly and stoichiometrically with periodate at 50-65°. If the excess periodate is determined spectrophotometrically,102 a sensitive and convenient micromethod results (range 2-70 jug.). That this method will become the one of choice for m/o-inositol seems probable. It should be applicable to the other inositols, and, perhaps, with some modifications, to inositol methyl ethers, quercitols, etc. Most interfering substances are effectively removed by vigorous treatment with hot, concentrated hydrochloric acid,101(a) sulfuric acid,103 or barium hydroxide,101[Pg.158]

Some of the inositol methyl ethers appear to be widely spread in Nature. Many new occurrences (not tabulated by Dangschat2(d)) have been reported for (+)-pinitol,146,163,161,162 quebrachitol,163,162 and sequoyitol.163,162 It is interesting that pinitol and sequoyitol frequently occur in the same plants. 

The barium hydroxide catalyzed Henry reaction of 6-deoxy-3-0-methyl-6-nilro-L-ta/r -pyra-nosc (17), generated from l,2-0-isopropylidcnc-3-0-mcthyl-o -D-r/7to-pcntodialdo-1.4-furanose (16), furnishes 5-deoxy-2-GMnethyl-5-nitro-wi o-inositol (18) in 92% yield and 90% purity1 2 3 4 5 6. 

There is evidence for immunosuppressive effects of PAHs in rodents (Davila et al. 1997). For example, strong immunosuppressive effects were reported in mice that had been dosed with benzo[fl]pyrene and 3-methyl cholanthrene, effects that persisted for up to 18 months (Environmental Health Criteria 202). Multiple immu-notoxic effects have been reported in rodents, and there is evidence that these result from disturbance of calcium homeostasis (Davila et al. 1997). PAHs can activate protein tyrosine kinases in T cells that initiate the activation of a form of phospholipase C. Consequently, release of inositol triphosphate—a molecule that immobilizes Ca + from storage pools in the endoplasmic reticulum—is enhanced. 

In the case of the cyclopentane oxirane 424, fluorination [KHFj, Me0(CH2)20H] proceeded to give preferably one fluoroalcohol, 426 (61%) over the isomeric one, 425 (7%), possibly by the influence of the benzyloxy-methyl group. Similarly (KHF2, ethylene glycol, 160°), another oxirane, 427, was converted into 428 (30%). 2-C-(Fluoromethyl)-/ T6>-inositol (429)... 

Carless HAJ, Oak OZ (1991) Total synthesis of (-)-laminitol (lD-4C-methyl-myo-inositol) via microbial oxidation of tolnene. Tetrahedron Lett 32 1671-1674. 

L. Sk0t and H. Egsgaard, Identification of ononitol and O-methyl-scyllo-inositol in pea root nodules. Plania 161 32-36 (1984). 

C17H24012 ( )-2-(Acetoxy methyl)-1,3,4,6-tetra-O-acetyl-epi-inositol AXMAIN 31 354... 

GFP hopo ICBP IP3 Ln3+ mal memal MLCK nota oxine par pdta pmea py quin-2 green fluorescent protein hydroxypyridinon(at)e intestinal calcium-binding protein inositol 1,4,5-triphosphate a lanthanide(III) cation malonate methylmalonate myosin light chain kinase 1,4,7-triazacyclononane-l,4,7-triacetate 8- hydroxyquinoline pyridine-2-azo-4 -dimethylaniline propylene-1,2-diaminetetraacetate 9- [2-(phosphonomethoxy)ethyl] adenine pjrridine pjrridyl 8-amino-2- [(2-amino-5-methylphenoxy )methyl] -6-methoxyquinoline-ATJV -tetraacetate 2- [ [2-[his(carboxymethyl)amino]-5-methyl-phenoxy] methyl] -6-methoxy-8- [bis(carboxymethyl) amino] quinoline]... 

As these acetals could be converted into the 4,6-O-ethylidene derivatives on treatment with acid, it was reasoned that use of a cyclic vinyl ether, namely, 3,4-dihydro-2H-pyran, might prevent this second process, thus leading to a more useful method of selective acetalation.338 An equimolar reaction with methyl a-D-glu-copyranoside for 4 days in N,N-dimethylformamide led to utilization of 88% of the glycoside, and the 6-(tetrahydropyran-2-yl) ether constituted —85% of the crude reaction-product. In contrast to the steric control apparent in this instance, reaction of 3,4-dihydro-2H-pyran with the axial and equatorial hydroxyl groups in dl-1,4,5,6-tetra-O-acetyl-mi/o-inositol was completely unselective,339 a fact that has been rationalized310 in terms of the probable mechanism of these reactions. 

Lithium(I) ions are small but strongly hydrated and could interfere with Mg(II) biochemistry. However, the favored mode of action is interference with Ca(II) metabolism via inhibition of enzymes in the inositol phosphate pathways (470-472). Inositol phosphates are responsible for mobilizing Ca(II) inside cells in response to external stimnlii. Lithium also stimulates glutamate release presumably via activation of the AT-methyl-D-asparate receptor and leads to Ca(II) entry (473). The increased influx of intracellular Ca(II) may activate phospholipase C and stimulate accumulation of inositol 1,4,5-triphosphate (473). 

Lehrfeld, J. HPLC separation and quantitation of phytic acid and some inositol phosphates in foods. J Agr Food Chem 1994 42(12) 2726-2731. Obata, H., K. Imai, N. Inoue, and M. Umebayashi. A highly sensitive quantitative determination of glutathione in plant roots by high performance gel filtration chromatography and fluoro-metic detection after pre-column derivatization with N-(7-dimethyl-amino-4-methyl coumarinyl)-malei-mide. Phytochem Anal 1994 5(5) 239-242. 

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