Phthalide chemical structure

PLANT Sources, chemical structures and classifications of natural phthalides Chemical Structure of Phthalide... 

In this article, we review the chemical structures and sources of the currently known naturally occurring phthalides of plant. Recent advances related to the biological activities of the extensively investigated natural phthalides are also described. As examples, we focus on the phthalide ingredients and medical uses of three commonly used phthalide-containing TCM herbs. 

In this review, the natural phthalides of plant origin are classified into four types based on chemical structure (Fig. (2-6)) 1) 3-substituted phthalides 2) non-3-substituted phthalides 3) phthalide dimers and 4) phthalide isoquinolines. The 3-substituted phthalide derivatives are further classified into two subtypes, namely non-alkaloid phthalides (Fig. (2 and alkaloid phthalides (Fig. (3 . Phthalide alkaloids without the isoquinoline structure are always 3-substituted and are accordingly subclassified as the... 

The details of the classifications and chemical structures of four types of natural phthalides are illustrated in Figs. (2-6). Most of the isolated natural phthalides belong to the 3-substituted phthalide type, which accounts for about 61% of the total known naturally occurring phthalides, and of these, non-alkaloid phthalides constitute the most important subtype due not only to their abundance in nature (75 compounds identified) but also their extensively reported pharmacological activities. The pharmacological activities of individual phthalides are discussed in the following Biological Activity Section. 

Other Names Phenolphthalein, 3, 3"-dimethyl- o-Cresolphthalein 3,3- X3-methyl-4-hydroxyphenyl)phthalide Cresolphthalein CA Index Name l(3H)-Isobenzofuranone, 3,3- iX4-hydroxy-3-methylphenyl)-CAS Registry Number 596-27-0 Merck Index Number 2576 Chemical Structure... 

Other Names Fluorescein 3, 6 -Dihydroxyfluoran 3, 6 -Fluorandiol 3,6-Dihydroxyspiro [xanthene-9,3 -phthalide] 9-(( -Carboxyphenyl)-6-hydroxy-3-isoxanthenone Benzoic acid, 2-(6-hydroxy-3-oxo-3H-xanthen-9-yl)- C.I. 45350 1 C.I. Solvent Yellow 94 D and C Yellow No. 7 D C Yellow No. 7 Fluorescein acid Japan Yellow 201 Japan Yellow No. 201 NSC 667256 Resorcinolphthalein Solvent Yellow 94 Yellow fluorescein CA Index Name Spiro[isobenzofuran-l(3H),9 -[9H]xanthen]-3-one, 3, 6 -dihydroxy-CAS Registry Number 2321-07-5 Merck Index Number 4159 Chemical Structure... 

The first case presented is that of 2-[(acyloxy)methyl]benzamides of the general structure 8.187 (Fig. 8.22) [239]. Two model compounds were examined (NRR = MeNH or morpholino, R" = Me) they reacted, as expected, to give the secondary amine and phthalide in quantitative yields. At pH 9.3 and 60°, chemical hydrolysis was 2-10 times faster than the subsequent cyclization-elimination. At pH 7.4 and 37°, the chemical hydrolysis was slow (f1/2 ca. 400 h), while hydrolysis in human plasma was fast (tm 3.2 and 1.4 h, respectively). 

When the partial structures corresponding to the substituted phthalides, 88 and 89, are incorporated into the alkaloids, 81-86 there was relatively little change in chemical shifts from those of the models except for the expected changes at the benzylic carbon atoms (C-T). 

N,A-Disubstituted 2-benzoylbenzamides 106 also formed chiral crystals in space group P212121. Irradiation of these crystals gave optically active phthalides 107 in high optical and chemical yields [97]. It was concluded from the x-ray structural analysis that the photoreaction promoted intramolecular cyclization to phthalides via a radical pair intermediate, not phenyl migration. 

Phthalides and phthalic anhydrides are extremely common components in a huge variety of polymers, and are prepared using many chemical processes. There are over 1300 references to polymers derived from phthalic anhydrides in the Registry File of Chemical Abstracts. Phthalic anhydride itself is used in polyester resins but there are also many examples of polyimides that are derived from related anhydrides. In this section, a few examples representing a range of structure and polymerization process are presented. 

The structure of the oxidation product of 2,5-dihydro[c]benzoselenophene has been revised to that of an aldehydic diselenide (177) and not a selena-phthalide as previously claimed. The latter structure, which contains a chemical bond connecting a rather hard carbonyl carbon to a soft selenium atom, is evidently destabilized. 

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