Holarrhena

Holarrhena spp., alkaloids, 742 pharmacological action, 748 Holarrhenine holarrhine, 743, 747 holarrhimine, 742, 743, 747 Homatropine, 74... 

More complex compounds containing enamine grouping, e.g., holarrhena alkaloids such as conkurchine and conessidine, possess an endocyclic rather than exocyclic double bond (159). On the other hand, 1 -methyl-2-alky Ipiperi-... 

Linolenic acid Linseed oil, hemp seed oil, perilla oil Holarrihidine holarrhena antidy, senterica... 

Apocynaceae Holarrhena floribunda Holarrhena antidysenterica Holaphyllamin Conessine... 

The stem bark of Holarrhena antidysenterica Wall. (Apocynaceae) yielded the known steroidal alkaloids holarrhimine, isoconessimine, and conimine (108). Leaves of Holarrhena curtisii King et Gamble yielded the known as well as new aminoglycosteroidal alkaloids holacurtine (102) and N-demethylholacurtine (103), respectively (109). 

Carbon source was found to be a significant factor in plant cell metabolism [34 - 39], which affected the accumulation of alkaloids by suspension cultures of Holarrhena antidysenterica [36], of anthocyanins by Vitis vinifera cell suspen-... 

Nitrogen source is also very important for plant cell metabolite formation, as reported in suspension cultures of Holarrhena antidysenterica for accumulation of alkaloids [36], in cell suspensions of Vitis vinifera for anthocyanin formation [37], and in shikonin production by Lithospermum erythrorhizon cell cultures [38]. 

A new alkaloid, holacetine (la), has been isolated in 0.04% yield from the root bark of Holarrhena antidysenterica, together with the known component cones-sine.1 Acetylation of holacetine gave an O-acetyl derivative (lb), vigorous acid-catalysed hydrolysis of which yielded the (20S)-20-amino-pregnane (lc). The identity of the latter, and hence of holacetine, was established by its conversion via standard methods into the known alkaloid funtumafrine C (2), and by its preparation from (20S)-3/3-hydroxypregn-5-ene-20-carboxylic acid.1 Conessine has been identified in tissue cultures of H. antidysenterica.2... 

Extraction of the leaves of Holarrhena curtisii that had grown in Thailand yielded the known constituent holacurtine (6a) together with a new alkaloid.6 The latter was assigned the structure A-desmethylholacurtine (6b) on the basis of spectroscopic comparison with holacurtine. The H n.m.r. spectrum of A -acetyl-holacurtine (6c) showed two resonances each for the 0-methyl, A-methyl, and secondary C-methyl groups, which was interpreted to mean that the amide group... 

The fission mechanisms assigned were proved by labeling.168 The proposed structure of a-hydroxyconnessine was confirmed by mass spectrometry166 and several steroidal alkaloids occurring in Holarrhena could be detected and identified.170... 

An alkaloid obtained from the seeds of Holarrhena antidysenterica (Apocynaceae). 

Holarrhena antidysenterica, 493 Holocaine, 869 Holopon, 675 Homapin, 661 Homat, 660 Homatropine, 660 Homatropine hydrobromide, 660 Homatropine methobromide, 661 Homatropine methylbromide, 661 Homidium bromide, 661 Homochlorcyclizine, 661... 

The steroidal alkaloids have a nucleus based on 21, 24, or 27 carbon atoms (Fig. 44). The C21 alkaloids are pregnane-derived with nitrogen inserted at C-3, at C-20, or at both positions. They are characteristic of the Apocynaceae Funtumia and Holarrhena species) and the Buxaceae Buxus species). The Buxaceae also produces C24 alkaloids based on the cycloartane skeleton. The most interesting alkaloids are those in the Solanaceae and the Liliaceae. These are C27 alkaloids, and examples include solasodine and solanidine many derivatives are glycosylated. The alkaloids from the Liliaceae, such as veratramine of the white hellebore (Veratrum album), were formerly used for cardiac... 

Steroid alkaloids were also found in Funtumia and Malouetia. The genus Funtumia comprises tropical trees indigenous to equatorial and West Afrika. Alkaloids found therein belong to types I and II. Many contain only one atom of nitrogen and an oxygen function in positions 3 or 20 in comparison Holarrhena alkaloids exhibit this type of substitution much less frequently. 

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