A New (–)-5′,6-dimethoxyisolariciresinol-(3″,4″-dimethoxy)-3α-O-β-D-glucopyranoside from the bark of Aglaia eximia (Meliaceae)

Abstract New (–)-5′,6-dimethoxyisolariciresinol-(3″,4″-dimethoxy)-3α-O-β-d-glucopyranoside compound was isolated from the methanol extract of the bark of Aglaia eximia (Meliaceae). The chemical structure of the new compound were elucidated on the basis of spectroscopic data including, UV, IR, HR-ESI-TOFMS, 1D-NMR, 2D-NMR and comparison with those related compounds previously reported.

Recently, a cyclopenta benzofurans derived from lignan, named aglacins A-H, a new class of aryltetralin cyclic ether lignans and norlignans have been found from A. cordata species of Kalimantan Aglaia plant, Indonesia (Wang et al. 2001(Wang et al. , 2002(Wang et al. , 2004. In the course of our continuing search for cytotoxic compounds from Indonesian Aglaia plant, we isolated and elucidated a new stigmastane steroid, 3,4-epoxy-(22R,25)-tetrahydrofuran-stigmast-5-en (Harneti et al. 2014) as well as two new bisamides, eximiamide A and eximiamide B (Sianturi et al. 2015) from the bark of Aglaia eximia. In further screening from more polar fraction of A. eximia species, we found the new glycosylated lignan from methanol extract of the bark of A. eximia. We report herein the isolation and structure elucidation of the new (-)-5′,6-dimethoxyisolariciresinol-(3″,4″-dimethoxy)-3α-O-β-d-glucopyranoside.

General experimental procedures
UV spectra were measured by using Shimazu UV-8452A with methanol. Optical rotations were recorded on an ATAGO AP-300 automatic polarimeter. The IR spectra were recorded on a Perkin-Elmer spectrum-100 FT-IR in KBr. Mass spectra were obtained with a Waters, Qtof HR-MS XEV otm mass spectrometer. NMR spectra were obtained with a JEOL JNM A-500 spectrometer using TMS as an internal standard. chromatographic separations were carried out on silica gel 60 (70-230 and 230-400 mesh, Merck), Octa Desyl Silane (200-400 mesh, Fuji Silysia). The fractions were monitored by TLc with silica gel GF 254 (Merck, 0.25 mm) and silica gel RP-18 F 254 (Merck, 0.25 mm) and spots were detected by 10% H 2 SO 4 in ethanol followed by heating.

Plant materials
The bark of A. eximia were collected in Bogor Botanical Garden, Bogor, West Java Province, Indonesia in June 2011. The plant was identified by the staff of the Bogoriense Herbarium, Bogor, Indonesia and a voucher specimen (No. Bo-1295315) was deposited at the herbarium.

Conclusion
An isolariciresinol-type lignan has been isolated from the bark of A. eximia (Meliaceae).

Disclosure statement
No potential conflict of interest was reported by the authors.