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We studied the alkaloid composition of Annona muricata L. (Annonaceae) leaves collected in February 2009 in Conakry Botanical Garden (Republic of Guinea). Ordinary CHCl 3 extraction afforded total alkaloids (0.125%) that were separated into phenolic and nonphenolic parts. Column chromatography over silica gel of the nonphenolic fraction isolated three bases; of the phenolic fraction, one. Spectral data, physical constants of the alkaloids and their salts, chemical transformation, and comparison with authentic samples identified the pure alkaloids. Base 1, C 17 H 15 NO 2 , mp 120-122°C, mass spectrum (m/z): 265 [M] + , 264 [M-1] + (100), 250, 236, 235; identified as anonaine [1, 2]. Base 2, isolated as the hydrochloride, C 19 H 19 NO 3 •HCl, mp 244-246°C, identified as isolaureline [3, 4]. Base 3, C 18 H 17 NO 3 , mp 124-126°C (acetone), UV spectrum (O max , EtOH): 219, 282 (log H 4.49, 4.25), spectrum similar to that of isolaureline. The mass spectrum of 3 had peaks for ions (m/z) 295 [M] + , 294 [M-1] + , 280 [M-15] + , 266 [M-29] + , and 147.5 [M] ++ that were characteristic of noraporphine alkaloids. A comparison of spectral data of 3 and 2 in addition to the difference in the molecular weights by 14 mass units suggested that 3 was norisolaureline. In fact, Hess methylation of 3 produced a base that was identical to 2. According to these results, 3 was identified as xylopine [2, 5]. Base 4, C 17 H 19 NO 3 , phenolic crystalline base, mp 218-220°C (acetone), identified as coclaurine [6, 7]. Thus, we studied the alkaloid composition of Annona muricata leaves and isolated for the first time and identified the aporphine alkaloids anonaine, isolaureline, and xylopine and the benzyltetrahydroisoquinoline alkaloid coclaurine, which was isolated previously from this plant [7].

We previously isolated from leaves of Annona muricata L. (Annonaceae) and characterized the alkaloids anonaine, xylopine, isolaureline, and coclaurine. In continuation of the study of alkaloids from leaves of A. muricata collected in the Republic of Guinea, we communicate the isolation from the phenolic and non-phenolic parts of total bases another five alkaloids (1-5).Phenolic and non-phenolic fractions of total alkaloids were separated using chromatography over a column of silica gel. Alkaloids were eluted by benzene and C 6 H 6 :EtOH in various ratios (99:1, 98:2, 95:5, and 90:10). The separation was monitored by TLC analysis. Eluates containing pure compounds were combined and condensed. Crystals of alkaloids were isolated by recrystallization from benzene, acetone, and CHCl 3 and by preparation of their salts. The pure alkaloids obtained in this manner were identified by chromatographic mobility, physical constants, and comparison of spectral data and with authentic samples. [3,5].Base 4, non-phenolic, optically inactive, isolated as the hydrochloride of formula C 18 H 17 NO 2 ·HCl, mp 263-265°C (dec.), identified as remerine [6,7]. Base 5, C 17 H 9 NO 3 , non-phenolic, optically inactive, high-melting crystalline base, yellow, mp 273-275°C (CHCl 3 ). Comparison of data given above with the literature [8,9] suggested that 5 was liriodenine. A mixed sample with an authentic sample of liriodenine did not depress the melting point. One spot was seen on TLC.Thus, another five bases, benzyltetrahydroisoquinoline N-methylcoclaurine (1), aporphine asimilobin (2), remerine (3), isoboldine (4), and oxoaporphine liriodenine (5) were isolated from leaves of A. muricata and identified in addition to previously described alkaloids [1]. Alkaloids 2-5 were found for the first time in this plant species. REFERENCES1.

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