@article{94d04a277f9f4b2f850c4a5e04d4707f,
title = "Natural anti-HIV agents - Part I: (+)-Demethoxyepiexcelsin and verticillatol from Litsea verticillata",
abstract = "The eudesmane sesquiterpenoid, verticillatol (1), as well as the lignan, (+)-5′-demethoxyepiexcelsin (2), and a known lignan, (+)-epiexcelsin (3), were isolated from Litsea verticillata Hance. Lignan 2 showed moderate anti-HIV activity with an IC50 value of 16.4 μg/ml (42.7 μM), while the known lignan 3 was inactive up to a concentration of 20 μg/ml (48.3 μM). Compound 1 demonstrated weak activity with an IC50 value of 34.5 μg/ml (144.7 μM) while being devoid of cytotoxicity at 20 μg/ml. The structures were elucidated by ID and 2D NMR spectroscopy, and the absolute configuration of the new sesquiterpenoid was determined by the generation of Mosher esters.",
keywords = "(+)-5′-Demethoxyepiexcelsin, 2D NMR, Absolute structure, Anti-HIV activity, Green fluorescent protein, HOG.R5, Lauraceae, Lignan, Litsea verticillata, Reporter cell line, Sesquiterpene, Verticillatol",
author = "Hoang, \{Vu Dinh\} and Tan, \{Ghee Teng\} and Hongjie Zhang and Tamez, \{Pamela A.\} and Hung, \{Nguyen Van\} and Cuong, \{Nguyen Manh\} and Soejarto, \{D. Doel\} and Fong, \{Harry H.S.\} and Pezzuto, \{John M.\}",
note = "Funding Information: Sample collections, taxonomic identification of samples, bioassay-guided chemical isolation, and structure elucidation work presented in this paper were made under a grant 1-UO1-TW01015, International Cooperative Biodiversity Groups Program, through funds from NIH, NSF, and the Foreign Agricultural Service of the USDA, administered by the Fogarty International Center, NIH ( Soejarto et al., 1999 ). Permits for the collection of samples of L. verticillata and its export from Vietnam were granted by the Ministry of Agriculture and Rural Development, Hanoi, Vietnam, through a letter dated 15 September 1998, Ref. No. 3551/BNN/KHCN, and from the Cuc Phuong National Park, through a letter dated 16 September 1998. The authors are grateful to the staff of the Cuc Phuong National Park for assistance with the recollection of L. verticillata samples used in the present study, and to the Research Resources Center, University of Illinois at Chicago for access to the Bruker DRX 500 MHz NMR instrument. The authors also wish to acknowledge the Mass Spectrometry Service Lab, Department of Chemistry, University of Minnesota for the acquisition of the MS data, and the AIDS Research and Reference Reagent Program, NIAID, NIH for the supply of reagents critical to this study. P.A.T. is the recipient of a pre-doctoral fellowship by the American foundation for Pharmaceutical Education.",
year = "2002",
month = feb,
day = "20",
doi = "10.1016/S0031-9422(01)00454-X",
language = "English",
volume = "59",
pages = "325--329",
journal = "Phytochemistry",
issn = "0031-9422",
publisher = "Elsevier Ltd.",
number = "3",
}
