(−)-3-Bromomethyl-3-chloro-7-methyl-1, 6-octadiene from Sri Lankan Chondrococcus hornemanni

Isolation and Structure/Activity Features of Halomon-Related Antitumor Monoterpenes from the Red Alga Portieria hornemannii

“…Solvent-solvent partitioning of a portion of the extract between hexane and 10% aqueous methanol gave a monoterpene-rich hexane fraction, which was permeated through Bio-Beads S-X4. After removal of most of the halomon (1) by crystallization, normal-phase HPLC on silica gel yielded additional quantities of halomon and five other monoterpenes (2)(3)(4)(5)(6). Isohalomon (2) eluted as a shoulder on the backside of the halomon peak and was purified by repeated peakshaving and recycling.…”

“…Preliminary photographs showed orthorhombic symmetry. Accurate lattice constants of a = 6.414(1), b = 18.538 (5), and c = 12.466(2) Á were determined from 25 diffractometer-measured 2 values. Systematic absences, density considerations, and chirality were uniquely accommodated by space group P2i2i2i, with one molecule of composition CioHi5Br2Cl3 in the asymmetric unit.…”

Isolation of Halogenated Monoterpenes from Bioreactor-Cultured Microplantlets of the Macrophytic Red Algae Ochtodes secundiramea and Portieria hornemannii

“…For example, field collections of Ochtodes species contain cyclic halogenated monoterpenes, [4][5][6] all based on an ochtodane template that is presumably formed by bromonium-ion-promoted cyclization of acyclic monoterpenes. 7,8 In contrast, field collections of Portieria hornemannii contain a plethora of acyclic halogenated monoterpenes, [9][10][11][12][13][14] some of which exhibit potent and selective antitumor activity. 14,15 P. hornemannii also contains cyclic halogenated monoterpenes based upon the ochtodane template.…”

“…Although halogenated monoterpene biosynthesis in both Ochtodes and Portieria may share myrcene as the common precursor, specific halogenated monoterpenes found in various field collections of these organisms differ markedly. For example, field collections of Ochtodes species contain cyclic halogenated monoterpenes, − all based on an ochtodane template that is presumably formed by bromonium-ion-promoted cyclization of acyclic monoterpenes. , In contrast, field collections of Portieria hornemannii contain a plethora of acyclic halogenated monoterpenes, − some of which exhibit potent and selective antitumor activity. , P. hornemannii also contains cyclic halogenated monoterpenes based upon the ochtodane template. − Interestingly, P. hornemannii contains monoterpenes that are only chlorinated, ,, whereas O. secundiramea does not, suggesting variations in halogenation enzyme activity.…”

Synthesis of Several Naturally Occurring Polyhalogenated Monoterpenes of the Halomon Class1

“…Three of these new compounds ( 2 , 4 , 5 ) also exhibited differential cytotoxicity comparable to halomon 1 in the NCI cell lines. It is interesting that nearly all of these same compounds had been isolated from the same red alga (called Chondrococcus hornemanni then but renamed P. hornemannii later) by Moore and his co-workers many years earlier, although the relative and absolute stereochemistry was not determined. A recent report indicates that halomon 1 is highly bioavailable and well distributed in the body, especially in fatty tissues …”