The study presents a new pathway for the enantioselective synthesis of benzylisoquinoline alkaloids. The key steps of the synthesis of (+)‐(S)‐laudanosine (1) and (–)‐(S)‐xylopinine (2) are a Sonogashira coupling that builds up the C1–C8a bond of the benzylisoquinoline skeleton, an intramolecular Ti‐catalyzed hydroamination of an alkyne, and a subsequent enantioselective imine reduction according to Noyori’s protocol. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

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A new farnesylated flavonol derivative, macagigantin (1), together with two known flavonoids, glyasperin A (2) and apigenin (3), had been isolated from the acetone extract of the leaves of Macaranga gigantea. The structure of the new compound was elucidated as 6-farnesylkaempferol based on its spectroscopic data, including UV, IR, 1D and 2D NMR, and HR-EI-MS spectra. Compounds 1-3 were evaluated for their cytotoxic properties against P-388 cells, their IC(50) values being 11.3, 6.0, and 5.1 microM, respectively.

Background: Eusiderin A is a neolignan derivate, which makes up the majority of the secondary metabolite of Eusideroxylon zwageri. It has been reported as a potent biopesticide and antifungal agent. Previous studies on the oxidation of terminal methylene of the allylic chain in Eusiderin A have been able to produce primary alcohol, pinacol, and an aldehyde which demonstrated strong activity against plant pathogenic fungi, therefore activity against dermal fungi needs to be studied. Objective: The current study aims to improve the hydrophilicity of Eusiderin A via oxidation of the allylic chain in order to derive a potent antifungal property. Methods: Transformation of Eusiderin A has been achieved by using the Wacker Oxidation Method in combination with the α-Hydroxylation-Ketone Method to produce 7,3’-epoxy-8,4’-oxyneolignane-1’- carboxylic acid. The structure of the 7,3’-epoxy-8,4’-oxyneolignane-1’-carboxylic acid was identified from spectroscopy data. The in vitro antifungal activity study was performed using the paper disc diffusion method against Trichophyton mentagrophytes. Results: New molecule of natural Eusiderin A through the oxidation of the allylic chain to increase the hydrophilicity of Eusiderin A has been designed. Based on the observed UV, IR, 1H and 13C-NMR, and MS spectra, it can be stated that the 7,3’-epoxy-8,4’-oxyneolignane-1’-carboxylic acid has been formed. At a concentration of 50 ppm, this compound showed antifungal activity against Trichophyton mentagrophytes. Conclusion: It can be concluded that the 7,3’-epoxy-8,4’-oxyneolignane-1’-carboxylic acid is a potent antifungal agent as it is able to inhibit the Trichophyton mentagrophytes colonies growth.