Abstract

The dried leaves and the bark of the Madagascar plant Physena madagascariensis are rubbed on clothing as a repellant against terrestrial leeches that infest certain regions on the island. The crude methanolic extract of the dried leaves showed significant antibacterial activity against a variety of species. Using this activity to guide the isolation through a series of chromatographic procedures, two novel flavanones 1 and 2 were identified as the active constituents using extensive NMR and MS studies to determine the structures. The S absolute stereochemistry was established for the C2 stereogenic center using circular dichroism, but the relative stereochernistry between this center and the stereogenic center on the lavandulyl side chain could not be determined on the. parent flavanones. Acid catalyzed cyclization of 1 produced pyranoflavanone 3 quantitatively. A weak NOE was observed in the Hl""""""""P proton upon irradiation of H2, an experiment run at CM[R at 600 MHz. The stereochernistry at H2"""""""" was then established as S on the basis of the coupling constants with the Hl"""""""" protons. 2' N 0 E OH p-TsOH H H OH 2 1: R= H 0 0 2 0 H 2: R = OH H Oil; k 0 Sk '!~; r~R A~ 3 OH 0 OH 0

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Biotechnology Resource Grants (P41)
Project #
5P41RR000995-26
Application #
6449624
Study Section
Project Start
2001-05-01
Project End
2002-04-30
Budget Start
Budget End
Support Year
26
Fiscal Year
2001
Total Cost
Indirect Cost

  Institution

Name
Massachusetts Institute of Technology
Department
Type
DUNS #
City
Cambridge
State
MA
Country
United States
Zip Code
02139

  Publications

Marintchev, Assen; Edmonds, Katherine A; Marintcheva, Boriana et al. (2009) Topology and regulation of the human eIF4A/4G/4H helicase complex in translation initiation. Cell 136:447-60
Frueh, Dominique P; Arthanari, Haribabu; Koglin, Alexander et al. (2009) A double TROSY hNCAnH experiment for efficient assignment of large and challenging proteins. J Am Chem Soc 131:12880-1
Frueh, Dominique P; Leed, Alison; Arthanari, Haribabu et al. (2009) Time-shared HSQC-NOESY for accurate distance constraints measured at high-field in (15)N-(13)C-ILV methyl labeled proteins. J Biomol NMR 45:311-8
Lentz, Margaret R; Westmoreland, Susan V; Lee, Vallent et al. (2008) Metabolic markers of neuronal injury correlate with SIV CNS disease severity and inoculum in the macaque model of neuroAIDS. Magn Reson Med 59:475-84
Hyberts, Sven G; Heffron, Gregory J; Tarragona, Nestor G et al. (2007) Ultrahigh-resolution (1)H-(13)C HSQC spectra of metabolite mixtures using nonlinear sampling and forward maximum entropy reconstruction. J Am Chem Soc 129:5108-16
Chen, Jingyang; Dupradeau, Francois-Yves; Case, David A et al. (2007) Nuclear magnetic resonance structural studies and molecular modeling of duplex DNA containing normal and 4'-oxidized abasic sites. Biochemistry 46:3096-107
Lentz, Margaret R; Kim, John P; Westmoreland, Susan V et al. (2005) Quantitative neuropathologic correlates of changes in ratio of N-acetylaspartate to creatine in macaque brain. Radiology 235:461-8
Kim, John P; Lentz, Margaret R; Westmoreland, Susan V et al. (2005) Relationships between astrogliosis and 1H MR spectroscopic measures of brain choline/creatine and myo-inositol/creatine in a primate model. AJNR Am J Neuroradiol 26:752-9
Peled, S; Cory, D G; Raymond, S A et al. (1999) Water diffusion, T(2), and compartmentation in frog sciatic nerve. Magn Reson Med 42:911-8
Mo, H; Dai, Y; Pochapsky, S S et al. (1999) 1H, 13C and 15N NMR assignments for a carbon monoxide generating metalloenzyme from Klebsiella pneumoniae. J Biomol NMR 14:287-8

Showing the most recent 10 out of 12 publications