Dendrobium lohohense

Shihunine (57), previously isolated from Dendrobium lohohense Tang and Wang (99, 100) andD. pierardii Roxb. (Orchidaceae) (101), has been found as a racemate in Banisteriopsis caapi Morton (102). This plant species also contained the optically active dihydroshihunine 58, a compound only known before as a racemic synthetic material. Both 57 and 58 were identified by direct comparison with authentic samples. The absolute configuration of (+)-(58) was determined as 25 by comparison of the CD spectra of 58 and of the a-phenylethylamines (102). 

Shihunine, C12H13O2N (mp 79° picrate, mp 163°-164°) (I) was obtained from Dendrobium lohohense Tang et Wang (4) its phthalide-pyrrolidine structure was established by reduction and decarboxylation to 1-methyl-2-phenylpyrrolidine, by oxidation to phthalic acid, and with the help of IR-spectral data. 

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