The bulbs of Cofcbicnm szovitsii of Turkish origin produce the phenethylisoquinolines (+)-colchiethanamine (21 and (+)-colchiethine 131. The well-characterized hexaoxygenated bispheneth ylisoquinoline alkaloid ( -) melanthioidine 111, present in Androrymbium melantbioides (Liliaceae) (l), is possibly formed in nature by phenolic oxidative coupling of two identically substituted trioxygenated phenethylisoquinolines. The monomer in question should be dioxygenated in ring A and monooxygenated in ring C. At the initiation of the present work, four monomeric phenethylisoquinolines were known, namely (- kautumnaline (2), (-)-isoautumnaline (2), (+)-dysoxyline (3), and (+)-homolaudanosine (3). Interestingly, all four are either dioxygenated or trioxygenated in ring C, and thus bear no direct relationship to the putative precursor for (-)-melanthioidine 111. We now describe two new phenethylisoquinolines which are, indeed, dioxygenated in ring A and monooxygenated in C. The bulbs of Cokcbicum szovitsii Fish. et Mey. (Liliaceae) are known to produce a variety of colchicine and homomorphinandienone alkaloids (4). We have found that the bulbs of C. szovitsii of Turkish origin also produce the phenethylisoquinolines (+)-colchiethanamine E21 and (+)-colchiethine 131. 'Permanent address: Faculty of Chemistry, Univenidad de Santiago de Compostela, Spain. *Permanent address: Faculty of Pharmacy, Ege Univeniry, Bornova, Izmir, Turkey. The ir spectrum of (+)-colchiethanamine [2], C1&123N03, showed a broad hydroxyl absorption, while the uv spectrum underwent a bathochromic shift in base, denoting the presence of at least one phenolic function.The mass spectrum displayed a small molecular ion mlz 3 13 and base peak mlz 192, representing rings A and B of the alkaloid.The 'H-nmr spectrum in CDCI, at 360 MHz is summarized around structure 2. Chemical shift assignments were confirmed through appropriate spin decoupling and nOe experiments (see Experimental).In order to confirm the assigned structure, the total synthesis of (+)-colchiethanamine was carried out via a classical route as shown in Scheme 1, i.e., through the sequence 5a-6a-7a-Sa-2. The spectral data for the synthetic (+)-colchiethanamine were identical with those of the natural product 2. The uv, ir, and ms spectra of( +)-colchiethine [3], C2,H2,N03, our second new alkaloid, were very close to those of (+)-colchiethanamine [2]. The mass spectrum again showed base peak mlz 192 and a very small molecular ion mh 327, suggesting the presence of a second methoxyl group in place of a hydroxyl. This was confirmed by the nmr spectrum, which showed two methoxyl singlets, one at 6 3.79 and the other at 3.84. In order to elucidate the complete structure of (+)-colchiethine, and in particular the positions of the two methoxyl groups and the hydroxyl function, the total syntheses of the two isomers (+)-[3] and (+)-E41 were carried out as shown in Scheme 1, following the sequences 8a-3 and 5bH6bHW8bH4. The chemical shifts for 3 and 4 are given around the respective structures. The.spectra1 data for our second alkaloid, (+) colchiethine, corresponded to those for synthetic isomer 3.The absolute configurations for both (+)-colchiethanamine [27 and (+)-col-chiethine [3] were indicated by their positive specific rotations, which derive from their S configurations (5). While (+)-colchiethanarnine 127 and (+>colchiethine [3] are the first phenethylisoquinolines dioxygenated in ring A and only rnonooxygenated in ring C, it is doubtful that they bear a direct relationship to the presumed biogenetic precursor for (-)-rnelanthioidine 111. In the first place, a phenethylisoquinoline of the R configuration is required as the building block of 1, whereas (+ >2 and (+ >3 have the S configuration. Secondly, the (-)-rnelanthioidine precursor demands a phenol at C-7 and a rnethoxyl at C-6, while (+)-2 and (+>3 have the opposite arrangement, with the phenol at C-6 and the methoxyl at C-7.