Journal of Applied Pharmaceutical Science Vol. 5 (04), pp. 033-039, April, 2015 Available online at http://www.japsonline.com DOI: 10.7324/JAPS.2015.50406 ISSN 2231-3354 Terpenoids and Sterols from Hoya multiflora Blume Virgilio D. Ebajo Jr.1, Chien-Chang Shen2, Consolacion Y. Ragasa1, 3* 1Chemistry Department, De La Salle University, 2401 Taft Avenue, Manila 1004, Philippines. 2National Research Institute of Chinese Medicine, 155-1, Li- Nong St., Sec. 2, Taipei 112, Taiwan. 3Chemistry Department, De La Salle University Science & Technology Complex Leandro V. Locsin Campus, Binan City, Laguna 4024, Philippines. ARTICLE INFO ABSTRACT Article history: Chemical investigation of the dichloromethane extracts of Hoya multiflora Blume led to the isolation of lupeol Received on: 30/01/2015 (1a), α-amyrin (1b), β-amyrin (1c), lupeol acetate (2a), α-amyrin acetate (2b), and β-amyrin acetate (2c) from Revised on: 12/02/2015 the stems; and 1b, bauerenol (3), squalene (4), lutein (5), β-sitosterol (6a), and stigmasterol (6b)from the leaves. 1 13 Accepted on: 07/03/2015 The structures of 1-6 were identified by comparison of their H and/or C NMR data with those reported in the Available online: 27/04/2015 literature. Key words: Hoya multiflora Blume, Apocynaceae, bauerenol, lupeol, lupeol acetate, α- amyrin, α-amyrin acetate, β- amyrin, β-amyrin acetate, squalene, lutein, β-sitosterol, stigmasterol. INTRODUCTION been reported (Baas et al., 1992). Moreover, the β-amyrin derivative 5-isopropyl-10 (2-methoxycarbonylethyl)des-A-olean- Hoya plants are also called wax plants due to the waxy 12-en and the taraxerol derivative 5-isopropyl-10 (2- appearance of their leaves or flowers. There are at least 109 methoxycarbonylethyl)des-A-olean-14-en were isolated from Hoya species of Hoya found in the Philippines, 88 of these are endemic lacunose (Baas, 1983). The oligosaccharides 6-deoxy-3-, O-methyl- to the country (Aurigue, 2013). The Hoya multiflora, also called β-allopyranosyl (1→4)- β-cymaropyranosyl (1→4)-β-cymaronic shooting-star hoya is indigenous to the Philippines. This plant acid δ-lactone and 6-deoxy-3-O-methyl-β-allopyranosyl (1→4)-β- was called multiflora due to its multiple flowers (about 40) in the oleandropyranosyl (1→4)-β-cymaropyranosyl (1→4)-β-cymaronic convex umbel (Aurigue, 2013). There are no reported chemical acid δ-lactone and its sodium salt were isolated from Hoya carnosa studies and biological activities on H. multiflora. However, (Yoshikawa et al., 2000). A review on the chemical and congeners of the plant have been studied for their chemical pharmacological aspects of Hoya species has been provided constituents. Gas chromatographic analysis on the chemical (Pandey et al., 2006). Hoya species yielded pregnanes, lipids, constituents of Hoya naumanii led to the detection of the sterols, flavanols, triterpenes, sesquiterpenes and disaccharides. triterpenes β-amyrin, lupeol and α-amyrin and their 3, 4-seco-3- They were reported to exhibit antinematodal activity, hypo oic acid methyl esters (Baas and Van Berkel, 1991). The sensitization, immunological properties and phytotoxicity; used for isolation of pentacyclic triterpenols δ-amyrin, β-amyrin, lupeol the treatment of occupational asthma and sea-squirt asthma and and α-amyrin and their 3, 4-seco-3-nor-2-ol derivatives allergies; and employed as antigens and insecticides (Pandey et al., (australinols A–D) from the leaf wax, of, Hoya australis, have 2006). This study was conducted as part of our research on the chemical constituents of the genus Hoya. We earlier, reported the * Corresponding Author Consolacion Y. Ragasa, Chemistry Department, De La Salle University, isolation of lupenone and lupeol from the roots; lupeol, squalene 2401 Taft Avenue, Manila 1004, Philippines. and β-sitosterol from the leaves; and betulin from, the stems of Email: [email protected] Hoya mindorensis Schlechter (Ebajo et al., 2014). © 2015 Virgilio Ebajo Jr. et al. This is an open access article distributed under the terms of the Creative Commons Attribution License -NonCommercial-ShareAlike Unported License (http://creativecommons.org/licenses/by-nc-sa/3.0/). 034 Ebajo Jr. et al. / Journal of Applied Pharmaceutical Science 5 (04); 2015: 033-039 Fig. 1: Chemical Constituents of Hoya multiflora lupeno (1a), lupeol acetate (2a), -amyrin (1b), α-amyrin acetate (2b), β-amyrin (1c), β-amyrin acetate (2a), bauerenol (3), squalene (4), lutein (5), β-sitosterol (6a), and stig masterol (6b). We report herein the isolation of lupeol (1a), α-amyrin performed with plastic backed plates coated with silica gel F254 and (1b), β-amyrin (1c), lupeol acetate (2a), α-amyrin acetate (2b), and the plates were visualized by spraying with vanillin/H2SO4 solution β-amyrin acetate (2c) from the stems; and 1b, bauerenol (3), followed by warming. squalene (4), lutein (5), β-sitosterol (6a), and stigmasterol (6b) from the leaves of Hoya multiflora Blume. To the best of our Sample Collection knowledge this is the first report on the isolation of these Hoya multiflora Blume was collected from a garden in compounds from H. multiflora. Pangasinan, Philippines in September 2013. Voucher specimens were authenticated at the Botany Division of the Philippine MATERIALS AND METHODS National Museum. General Experimental Procedure General Isolation Procedure NMR spectra were recorded on a Varian VNMRS The air-dried leaves (23.0 g), and stems (86.5 g) of H. 1 spectrometer in CDCl3 at 600 MHz for H NMR and 150 MHz for multiflora were ground in a blender, soaked in CH2Cl2 for three 13C NMR spectra. Column chromatography was performed, with days and then filtered. The filtrates were concentrated under silica gel 60 (70-230 mesh). Thin layer chromatography, was vacuum to afford crude extracts of leaves (2.0 g), and stems (1.0 g) . Ebajo Jr. et al. / Journal of Applied Pharmaceutical Science 5 (04); 2015: 033-039 035 which were each chromatographed by gradient elution with (C-6), 34.19 (C-7), 55.41 (C-8), 50.32 (C-9), 37.06 (C-10), 20.92 CH2Cl2, followed by increasing amounts of acetone at 10% (C-11), 25.07 (C-12), 38.02 (C-13), 42.05 (C-14), 27.42 (C-15), increment by volume as eluents. A glass column 12 inches in 35.55 (C-16), 47.63 (C-17), 48.27 (C-18), 47.99 (C-19), 150.96 height and 0.5 inch internal diameter was used for the fractionation (C-20), 29.81 (C-21), 40.01 (C-22), 28.07 (C-23), 15.72 (C-24), of crude extracts. Two milliliter fractions were collected. Fractions 15.96 (C-25), 16.17 (C-26), 14.49 (C-27), 18.22, 18.25 (C-28, C- with spots of the same Rf values were combined and 30), 109.34 (C-29), 171.01, 21.39 (OAc). rechromatographed in appropriate solvent systems until TLC pure isolates were obtained. Rechromatography and final purifications α-Amyrin acetate (2b) 13 were conducted using Pasteur pipettes as columns. One milliliter Colorless solid. C NMR (150 MHz, CDCl3): δ 38.44 fractions were collected. (C-1), 27.59 (C-2), 80.96 (C-3), 37.69C-4), 55.24 (C-5), 18.22 (C- 6), 32.85 (C-7), 40.01 (C-8), 47.63 (C-9), 36.77 (C-10), 23.35 (C- Isolation of Chemical Constituents of the Stems 11), 124.30 (C-12), 139.61 (C-13), 42.05 (C-14), 26.58 (C-15), The CH2Cl2 fraction from the chromatography of the 28.05 (C-16), 33.73 (C-17), 59.04 (C-18), 39.63 (C-19), 39.59 (C- crude extract was rechromatographed using 1% EtOAc in 20), 31.23 (C-21), 41.52 (C-22), 28.73 (C-23), 16.85 (C-24), 15.72 petroleum ether to afford a mixture of 2a-2c (9 mg) after washing (C-25), 16.73 (C-26), 23.21 (C-27), 28.73 (C-28), 17.50 (C-29), with petroleum ether. The 20% acetone in CH2Cl2 fraction was 21.39 (C-30), 171.01, 21.32 (OAc). rechromatographed using 5% EtOAc in petroleum ether, to afford a mixture of 1a-1c (4 mg) after washing with petroleum ether. β-Amyrin acetate (2c) 13 Colorless solid. C NMR (150 MHz, CDCl3), δ 39.59 Isolation of Chemical Constituents of the Leaves (C-1), 27.93 (C-2), 80.8 (C-3), 39.59 (C-4), 55.24 (C-5), 18.19 (C- The CH2Cl2 fraction from the chromatography of the 6), 33.73 (C-7), 38.37 (C-8), 47.4 (C-9), 35.55 (C-10), 23.59 (C- crude extract was rechromatographed (3 ×) using petroleum ether 11), 121.62 (C-12), 145.20 (C-13), 42.05 (C-14), 28.73 (C-15), to afford 4 (5 mg). The 30% acetone in CH2Cl2 fraction was 27.93 (C-16), 32.85 (C-17), 59.0 (C-18), 40.01 (C-19), 41.52 (C- rechromatographed (4×) using 20% EtOAc in petroleum ether to 20), 31.23 (C-21), 42.01 (C-22), 29.69 (C-23), 15.72 (C-24), 15.72 afford a mixture of 1b and 3 (15 mg) after washing with petroleum (C-25), 16.84 (C-26), 23.59 (C-27), 28.73 (C-28), 17.50 (C-29), ether. The 40% acetone in CH2Cl2 fraction was rechromatographed 21.39 (C-30), 170.8, 21.32 (OAc). (2×) using CH3CN:Et2O:CH2Cl2 (0.5:0.5:9, v/v) afford a mixture of 6a and 6b (4 mg) after washing with petroleum ether. The 60% Bauerenol (3) 13 acetone in CH2Cl2 fraction was rechromatographed using Colorless solid. C NMR (150 MHz, CDCl3): 36.87 (C- CH3CN:Et2O:CH2Cl2 (1:1:8, v/v) afford 5 (3 mg) after washing 1), 27.69 (C-2), 79.05 (C-3), 38.88 (C-4), 50.41 (C-5), 24.15 (C- with Et2O.