Carapanolides T–X from Carapa guianensis (Andiroba) Seeds

Two new mexicanolide-type limonoids, carapanolides T–U (1–2), and three new phragmalin-type limonoids, carapanolides V–X (3–5), were isolated from the seeds of Carapa guianensis (andiroba). Their structures were determined on the basis of 1D- and 2D-NMR spectroscopy.

unsaturation came from three carbon-carbon double bonds and three ester carbonyls, including a lactone carbonyl and ketone.
Me-28, H-30β; 2-OH (δH 4.05 (s))/H-12α, )/H-9, H-12α, )/H-5, H-11β, H-12β and H-30β, which indicated the α-orientation of H . Therefore, the relative structure of 1 was established as shown in Figure 1. Carapanolide U (2) was isolated as colorless needles and shown to have the molecular formula C32H40O10 (m/z: 585.2701 [M + H] + (calcd for 585.2700) by HRFABMS. IR and UV spectra revealed the presence of hydroxy and ester groups and an αβ-unsaturated δ-lactone at νmax 3537, 1748 and 1719 cm −1 , and λmax at 230 nm (log ε 4.11). The 1 H-and 13 C-NMR spectra of 2 (Table 1) were very similar to those of 1, except for the absence of the 2-methylpropanoyl group at C-3 and the presence of the tigroyl group at C-3. The relative structure of 2 was determined as shown in Figure 1.

General Procedures
Melting points were determined on a Yanagimoto micro-melting point apparatus and were uncorrected. Optical rotations were measured using a JASCO DIP-1000 digital polarimeter. IR spectra were recorded using a Perkin-Elmer 1720X FTIR spectrophotometer (Perkin-Elmer Inc., Wellesley, MA, USA). 1 H-and 13 C-NMR spectra were obtained on an Agilent vnmrs 600 spectrometer (Agilent Technologies, Santa Clara, CA, USA) with standard pulse sequences, operating at 600 and 150 MHz, respectively. CDCl3 was used as the solvent and TMS as the internal standard. FABMS were recorded on a JEOL-7000 mass spectrometer (JEOL, Tokyo, Japan). Column chromatography was performed over silica gel (70-230 mesh, Merck, Darmstadt, Germany), while medium pressure liquid Each value represents the mean˘the standard error (S.E.) of four determinations. Significant differences from the vehicle control (0 µM) group shown as * p < 0.05 and ** p < 0.01 in the NO inhibitory assay and # p < 0.05 and ## p < 0.01 in the cytotoxicity assay.

General Procedures
Melting points were determined on a Yanagimoto micro-melting point apparatus and were uncorrected. Optical rotations were measured using a JASCO DIP-1000 digital polarimeter. IR spectra were recorded using a Perkin-Elmer 1720X FTIR spectrophotometer (Perkin-Elmer Inc., Wellesley, MA, USA). 1 H-and 13 C-NMR spectra were obtained on an Agilent vnmrs 600 spectrometer (Agilent Technologies, Santa Clara, CA, USA) with standard pulse sequences, operating at 600 and 150 MHz, respectively. CDCl 3 was used as the solvent and TMS as the internal standard. FABMS were recorded on a JEOL-7000 mass spectrometer (JEOL, Tokyo, Japan). Column chromatography was performed over silica gel (70-230 mesh, Merck, Darmstadt, Germany), while medium pressure liquid chromatography (MPLC) was conducted with silica gel (230-400 mesh, Merck). HPLC was run on a JASCO PU-1586 instrument (JASCO, Tokyo, Japan) equipped with a differential refractometer (RI 1531). Fractions obtained from column chromatography were monitored by TLC (silica gel 60 F 254 , Merck).

Plant Material
The oil of (2.03 kg) Carapa guianensis AUBLET (Meliaceae) was collected in the Amazon, Brazil, in March 2013, and was kindly provided by Mr. Akira Yoshino (who is a representative of the "NGO Green Heart Love Amazon Project"). A voucher specimen (CGS-01-2) was deposited in the Herbarium of the Laboratory of Medicinal Chemistry, Osaka University of Pharmaceutical Sciences.