Phyllo

Nothing is known of the nature of krypto- and phyllo-pyrrole dimers and an investigation of their structure would be of great interest. 

In addition to the inorganic hydroxyl groups which are exposed on many mineral surfaces (metal oxides, phyllo-silicates and amorphous silicate minerals) we need to consider the particular features relating to charge on the silica surfaces of layer silicates. 

The principal role of vitamin K is in the post-translational modification of various blood clotting factors, in which it serves as a coenzyme in the carboxylation of certain glutamic acid residues present in these pro teins. Vitamin K exists in several forms, for example, in plants as phyllo quinone (or vitamin K-i), and in intestinal bacterial flora as Inenaquinone (or vitamin K2). For therapy, a synthetic derivative of vita rrri K, menadione, is available. 

Table 1 provides a fairly comprehensive listing of trivial names still in regular use in the porphyrin and chlorophyll area. The uro-, copro- and etio-porphyrins are examples of primary type isomer systems, while proto-, meso-, deutero- and hemato-porphyrins derive from the situation where 15 isomers exist. Phyllo-, pyrro- and rhodo-porphyrins, all being chlorophyll degradation products, are examples of the situation where there are four different kinds of porphyrin substituent. It transpires that, in biologically important porphyrin derivatives, the isomer chosen by Nature is Type-Ill (for the primary system), Type-IX (with three types of substituent) and Type-XV (with four). As can be seen in Schemes 1 and 2, primary type-III is related to type-IX in Scheme 2, and type-IX is in turn related to type-XV in the yet more complicated four-substituent system. 

Figure 2 Electronic absorption spectra (Soret band omitted) in chloroform a, etio type porphyrin b, rhodo type porphyrin c, oxorhodo type porphyrin d, phyllo type porphyrin...

Enzymatic hydrolysis is a nondestructive alternative to saponification for removing triglycerides in vitamin K determinations. For the simultaneous determination of vitamins A, D, E, and K in milk- and soy-based infant formulas and dairy products fortified with these vitamins (81), an amount of sample containing approximately 3.5-4.0 g of fat was digested for 1 h with lipase at 37°C and at pH 7.7. This treatment effectively hydrolyzed the glycerides, but only partially converted retinyl palmitate and a-tocopheryl acetate to their alcohol forms vitamin D and phyllo-quinone were unaffected. The hydrolysate was made alkaline in order to precipitate the fatty acids as soaps and then diluted with ethanol and extracted with pentane. A final water wash yielded an organic phase containing primarily the fat-soluble vitamins and cholesterol. 

In conclusion, exfoliated sheets of Mg-phyllo(organo)silicates containing pendant amino groups have been used to stabilize Au, Ag, Pd and Pt nanopartides. The nanoparticle-decorated day sheets can be easily dispersed in water. These metal nanopartides... 

Some bakery products ( puff pastries, phyllo) consist of flaky layers, made by rolling... 

Clay minerals are hydrous layer silicates of colloidal dimensions, with most if not all of the individual platy particles in the colloidal range of c. 1 nm-1 pm (van Olphen, 1976 Van Damme et al., 1985). The term phyllosilicate (phyllo = leaf like) is applied to the broad group of hydrous silicates with layer structures. The essentia] components of the phyllosilicate structure are two-dimensional tetrahedra and octahedra of oxygen atoms (or ions). The coordinating atoms (or cations) in the centre of the tetrahedra are for the most part Si, but Al3 or Fe3+ may also be present. The coordinating cations in the octahedra are usually Al3, Mg2+, Fe3 or Fe2. Some clay structures (e.g. hectorite) can be synthesized in a reproducible and relatively homogeneous form. 

Mineralogica1 structural types may have an effect on silica release rates as has been mentioned earlier. That is, isolated silica tetrahedra and small units (neso-, soro-silicates) release silica more quickly than single or double chains (ino-silicates) which in turn are more reactive than three dimensionally linked tetrahedra (tec to-silicates) or tetrahedra arranged in sheets (phyllo-silicates). But such structures are not the only cause for variations in silica release rates. 

Indane-2-carboxylic acid (89) has been converted in a similar manner (Scheme 16) to the hydrindene acid (90). A crucial step in the conversion of (-)-abietic acid into (+)-kaurene (93) and (-t-)-phyllo-cladene (94) involved the reduction of (91) to the mixture of epimers (92) combined with other doublebond isomers (Scheme 17). ... 

Batrachotoxin (459), the steroidal alkaloid from the poison arrow frog Phyllo-bates aurotaenia, continues to engage the attention of chemists and pharmacologists. This substance exerts novel, selective effects on electrogenic membranes. In many cases this activity can be explained in terms of an irreversible increase in permeability to sodium ions. The subsequent reactions promoted by (459) can be blocked reversibly by tetrodotoxin. ... 

Other lines of textural evidence, however, stiU provide support for asteroidal alteration of the Cl chondrites. These include (i) crosscutting phyllo-silicate-rich veins (Tomeoka, 1990) and (ii) the presence of carbonates that appear to represent fragments of an earlier generation of carbonate veins or resemble vein fillings (Richardson, 1978 Endress and Bischolf, 1996). 

The octahedral occupancy distinguishes these verdine facies or odinite minerals from other sedimentary and in fact all metamorphic phyllo-silicate minerals. These relations are clearly demonstrated by Hornibrook and Longstaffe (1996). 

CA. Neso-triborates 6.CB. Ino-triborates 6.CC. Phyllo-triborates 6.D Tetraborates... 

DA. Neso-tetraborates 6.DB. Ino-tetraborates 6.DC. Phyllo-tetraborates 6.DD. Tekto-tetraborates 6.E Pentaborates... 

EA. Neso-pentaborates 6.EB. Ino-pentaborates 6.EC. Phyllo-pentaborates 6.ED. Tekto-pentaborates 6.F Hexaborates... 

FA. Neso-hexaborates 6.FB. Ino-hexaborates 6.FC. Phyllo-hexaborates 6.G Heptaborates and other megaborates 6.H Unclassified borates... 

BD. Simple halides with H2O and additional OH 3.C Complex halides 3.CA. Borofluorides 3.CB. Neso-aluminofluorides 3.CC. Soro-aluminofluorides 3.CD. Ino-aluminofluorides 3.CE. Phyllo-aluminofluorides 3.CF. Tekto-aluminofluorides 3.CG. Aluminofluorides with CO3, SO4, PO4 3.CH. Silicofluorides... 

Very small amounts of frog secretions from Phyllo-bates terribilis, P. bicolor, and P. aurotanea can be used to poison dart tips, which are reportedly effective at immobilizing a variety of animals including jaguar, bear, deer, and humans. A single P. bicolor or P. terribilis can effectively poison 20-30 darts. 

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