The Chemistry of Eucalypt Kinos. IV. Eucalyptus hemiphloia Kino

Abstract

The kino exuded by Eucalyptus hemiphloia contains (+)-hemiphloin, isohemiphloin, (-)-eudesmin, aromadendrin, kaempferol, engelitin, ellagic acid, and small amounts of gallic acid. Hemiphloin and isohemiphloin appear to be 8-hexahydroxyhexyl derivatives of naringenin.

Revisiting kinos—An Australian perspective

“…Besides a recent NMR study of Eucalyptus spp. exudates (Lambert et al, 2007), limited research has since been conducted into the chemistry of these exudates, apart from some work carried out by Hillis in the 1950s and early 1960s using various chromatographic techniques (Hillis, 1951(Hillis, , 1952(Hillis, , 1960Hillis and Carle, 1962). His analysis, though useful, was restricted to only one or two kinos and therefore the resulting data relatively confined.…”

“…(+)-Hemiphloin, isohemiphloin, (−)-eudesmin, aromadendrin, kaempferol, engelitin, ellagic acid, gallic acid, dihydrokaempferol 3-rhamnoside (Maiden and Smith, 1895b;Hillis and Carle, 1962;Dayal, 1988) Eucalyptus maculata Hook. (Corymbia maculata Hook.)…”

Flavanones and Dihydroflavonols

“…Uoda et al, 1943. Maiden and Smith, 1896Hillis, 1952;Ganguly and Seshadri, 1961;Hillis and Carle, 1963;Hillis, 1966a, b;1967a, b, c, d. Satwalekar et al, 1957;Gell et al, 1958.…”

“…The first pair of compounds are the only known C-glycosylflavanones (including dihydroflavonols) known: (+ )-hemiphloin (41) or 6-C-glucosylnaringenin and isohemiphloin, the C-8 isomer (42). Both compounds were isolated from the kino of Eucalyptus hemiphloia by Hillis and Carle (1963). In a study of the differences between healthy and Poria weirii-infected Douglas fir (Pseudotsuga menziesii), Barton (1967a) isolated and identified poriol, 6-C-methylnaringenin (43), from the phenolic fraction.…”

Phenolic Compounds from the Branches of Eucalyptus maideni

“…Of them, oleuropeic acid derivatives may be evolved from terpineol, one of the major chemical constituents of Eucalyptus oil [24]. The isolated dihydroflavonoid, (þ)-aromadendrin, and phenolic compounds, (þ)-catechin, piceatannol, gallic acid, and 3-O-methylellagic acid 3'-O-a-l-rhamnopyranoside, also reported as the chemical constituents of E. kino, a dark exudate when the active cambium is injured [25], probably serve as the consistent preventive constituents of Eucalyptus maideni. The occurrence of macrocapals in the branches of E. maideni is very surprising, since they are reported to be inducible second metabolites involved in hostÀpathogen interactions in the wounded wood of E. globulus and E. nitens [26].…”