Annonaceae

Recent works on antitumor lactones from Annonaceae plants in China 99PAC1119. 

Synthesis of Annonaceae acetogenins with long aliphatic chain including tetra-hydrofuran fragments 97YGK877. 

The pseudobenzylisoquinoline alkaloids are fairly widespread in nature, being found among members of Berberidaceae, Annonaceae, Fumariaceae, and Ranunculaceae. The biogenesis of the pseudobenzylisoquinoline alkaloids assumes their formation from protoberberinium salts by C-8—C-8a bond scission in a Baeyer-Villiger-type oxidative rearrangement to produce the enamides of type 73 and 74. These amides may be further biotransformed either to rugosinone (76) type alkaloids by hydrolytic N-deformylation followed by oxidation or to ledecorine (75) by enzymatic reduction. These transformations were corroborated by in vitro studies (80-82). It is suggested that enamide seco alkaloids may be precursors of aporphine alkaloids (80), on one hand, and of cularine alkaloids (77), on the other. 

A list of the secobisbenzylisoquinoline alkaloids with their species of origin is included in Table VIII. The secobisbenzylisoquinoline alkaloids have mainly been found among members of the family Berberidaceae, less frequently in the Annonaceae, and in only a single case in the Ranunculaceae. In Table IX some of the physical data and spectral features of secobisbenzylisoquinoline alkaloids are presented. 

Taxonomically close to the Annonaceae, the Lauraceae family abounds with apor-phinoid alkaloids. A remarkable advance in the search for topoisomerase inhibitors from Lauraceae has been provided by Woo et al. (6). Using DNA-unwinding assay and structural modeling, they showed that dicentrine can attain a relatively planar conformation and molecular bulk which allow it to occupy the active site of topoisomerase II which becomes inactive. The requirement of a suboptimal conformation to achieve DNA binding appears to make dicentrine less potent against topoisomerase II than the... 

Lu Z, Yan Z, McLaughlin JL. Gigantransenins A, B, and C, novel mono-THF acetogenins bearing trans-double bonds, from Goniothalamus giganteus (Annonaceae). Tetrahedron Lett 1996 37 5449-5452. 

Whereas the Annonaceae are characterized primarily by benzylisoquinoline alkaloids, two pyrrolidine alkaloids have recently been found in species belonging to this family. Squamolone (29) was isolated from Annona squamosa L. by Chinese workers in 1962 (68). Despite careful spectroscopic investigation and a total synthesis (Eq. 1), squamolone was assigned the incorrect diazepine formula 30. The correct structural formula (29) was later established by an unambiguous synthesis of 30 (Eq. 2). Compounds 29 and 30 proved to have very similar spectroscopic properties, which could justify the early confusion (69). 

Mixed biogenesis sesouiterp.-shikim. fissistigmatins Fissistigma bracteolatum Chart., Annonaceae, Ang. fr n N Viernam Porzel 2000). 

Direct methylation through C-bonds appears to be common in the positions 6 and 8 of the flavonoid molecule. Other positions are rarely C-methylated (C7, saltillin C3, a glycoside only compound 23, Table 12.3). Most reports concentrate on species from the family Myrtaceae, where C-methylflavones also occur externally. Desmos cochinchinensis (Annonaceae) was... 

Rhamnosyl(l 2)-a-L-arabinofuranoside Artabotrys hexapetalus leaves Annonaceae 173... 

Quercetin 3,7-dimethyl ether 3 -Neohesperidoside Dasymaschalon sootepense leaves Annonaceae 398... 

OH-5,6,7-triOMe CigHigOfi 330 Kwangsienin A Fissistigma kwangsiense Annonaceae StemB 33... 

DiOH-7-OMe 6-Me C17H16O5 300 Friesodielsia enghiana Annonaceae StemB 56... 

OH-5-OMe 6-Me, 8-formyl C18H16O5 312 Desmosflavanone II Desmos cochinchinensis Annonaceae Root 66... 

Six new flavanones having one or more C-benzyl groups attached to C-6 or C-8, or both, have been reported from members of the Annonaceae, a family from which many C-benzylated flavanones and dihydrochalcones had previously been described. The new compounds (212-217) are presented in Table 15.6. Macrophyllol (212) and macrophyllol A (213, Figure 15.6) have been isolated from the roots of Uvaria macrophylla. These consist of 5-hydroxy-6,7-dimethoxyflavanone with one 2-hydroxy-5-methoxybenzyl unit attached to C-8 and C-6, respectively. The roots of Xylopia africana yielded isouvarinol (214, Figure 15.6), in which one 2-hydroxybenzyl unit is attached to C-6 and two units to C-8. Its... 

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