(Conti-'ibution from the Easio Sciences Research Department, U. S. Naval 

 Civil Engineering Research and Evaluation Laboratory, Port Hueneme, Calif.) 



TOXIC •]XTRAGTIVES OF GREENHEART 



by Peter J, Hearst, Richard Vif, Drisko, Thorndyke Roe, Jr., and 



Herbert McKennis, Jr, 



The commercial vjood, greenheart, variously identified as Demerra Green- 

 heart, Nectandra Rodioei, or Ocotea Rodioei, has long been recommended as 

 a timber of choice for the construction of vj-aterfront structures where 

 marine borer activity is high.^ The natural resistance of greenheart v;ood, 

 now emplo3''ed in many piers under the cognizance of the B^ireau of Yards and 

 Docks, has been occasionally attributed to the hardness of the material. 

 This remains a possibility. 



Van Iterson^, in considering the resistance of certain vraods, states that 

 greenheart, with a silica content of less than half of one per cent, does 

 not contain sufficient silica to endow it with any great resistance. Man- 

 barklak on the contraiy, v/hich contains one and one half per cent silica 

 is presumed to owe its resistance to silicious inclusions. Van Iterson 

 believed' the resistance of greenheart to be due to the presence of very 

 poisonous alkaloids. 



Bald'.Yin^ states that greenheart owes its power of resistance to its texture, 

 to the presence of the alkaloid knov.Ti as bebeerine, and to the resinous 

 tyloses. Liany others have attri.buted the resistance of greenheart to the 

 presence of the alcohol- soluble alkaloid, bebeerine. 



The oft-asserted protective action of bebeerine appat^ently finds its only 

 support in the early work of Barger and Hari-ington'^. These investigators 

 impregnated blocks of Baltic fir irith an alcoholic extract of greenheart 

 saivdust and fomid that these blocks resisted Teredo attack for tvio seasons. 

 From the alcoholic extract Barger and Haxrington-^ obtained ono-tenth of 

 one per cent, presumaUy based on the freight of the sawdust, of a non- 

 crystalline material reportedly corresponding to bebeerine. No evidence, 

 however, is presented to verify the identity of their material with 

 bebeerine . 



It thus appeared well worth. -wMle to investigate greenheart more thoroughly 

 from a chemical point of view and to determine ivhat kind of toxic substances 

 might be present in the wood. It was desired particularly to iso].ate and 

 study the alkaloids v/hich it contains, and to test these alkaloids to find 

 out which ones, if any, wer; toxic to marine borers. If bebeerine, or some 

 other alkaloid, is the active principle in greenheart, variation in the 

 alkaloid content of different samples of the v;ood might possibly be the 

 reason for the long life of greenheart pilings in some instances and the 

 relatively short life in others. 



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