Alkaloids isolated from Alseodaphne species (Lauraceae) and their bioactivities

Abstract

The phytochemical study on Lauraceae family (Alseodaphne corneri Kosterm, Alseodaphne pendulifolia Gamb., Alseodaphne perakensis (Gamb)Kosterm and Alseodaphne peduncularis (Wall.ex. Ness) Meissn) involves extraction, separation by using various chromatographic method and structural determination by spectroscopic techniques such as UV, IR, NMR including 1DNMR (1H, 13C, and DEPT), 2D-NMR (COSY, NOE-D, NOESY, HMQC/HSQC, and HMBC) and MS (LCMS and HRFABMS). The structures of the compounds were also elucidated by comparison with the previous works. Isolation works on the leaves of Alseodaphne corneri Kosterm (KL 4928) collected from University Malaya, Kuala Lumpur, yielded four aporphines; isocorydine 79, norisocorydine 80, N-methyllaurotetanine 83, laurotetanine 87, and four bisbenzylisoquinolines; obamegine 81, 2- norobamegine 84, (+)-2′-noroxyacanthine 55, and (+)-sepeerine 89. Meanwhile, the roots afforded one aporphine; norboldine 104, and seven bisbenzylisoquinolines; (-)-gyrolidine 91, norstephasubine 93, (+)-2- norobaberine 94, stephasubine 98, O-methyllimacusine 100, (+)-3′,4′- dihydrostephasubine 105) and O-methylrepandine 107. Seven compounds were successfully isolated from the leaves of Alseodaphne pendulifolia Gamb (KL 5250) collected from Sg. Temau Forest Reserved, Kuala Lipis, Pahang i.e; one oxoaporphine; oxohernagine 110; five aporphines; hernagine 111, corydine 112, isocorytuberine 113 and two new aporphine alkaloids; N-(2- ydroxypropyl)-pendulifoline A 108 and N-(2- hydroxypropyl)- pendulifoline B 109 and one bisbenzylisoquinoline; costaricine 114. Furthermore, this is the first report of alkaloids existence in the A. pendulifolia. Investigation of the alkaloidal constituents from the leaves of A. perakensis (Gamb) Kosterm (KL 5135) collected from KPK Sg. Merantor, Gua Musang, Kelantan yielded five aporphine alkaloids; N-methyllaurotetanine 83, norboldine 104 and three new apophines alkaloids; N-(2-hydroxypropyl)- norboldine A 115, N-(2-hydroxypropyl)-norboldine B 116 and N-cyanomethylnorboldine 117, and three new bisbenzylisoquinoline alkaloids; α′- oxoperakensimine A 118, α′-oxoperakensimine B 119 and α′- xoperakensimine C 120. Isolation and purification of alkaloids from the bark of A. peduncularis (KL 5165) collected from Kluang-Mersing, Johor, afforded five compounds; norlirioferine 121, lindcarpine 122, norpredicentrine 123, boldine 124 and laurotetanine 87 from aporphinoid group, and one new bisbenzylisoquinoline; α′-oxoperakensimine C 120. Bioassay study on the pure compounds of Alseodaphne species was found to possess vasorelaxant and antimalaria activity. In addition, three new compounds from A. perakensis; α′-oxoperakensimine A 118, α′- oxoperakensimine B 119 and α′- xoperakensimine C 120 showed vasorelaxant activity on induced contractions in the rat aorta strips.