Sesquiterpene Coumarins from Ferula gumosa Mehrdad Iranshahi,* ,†,§ Milena Masullo, ‡,§ Ali Asili, † Ali Hamedzadeh, † Bentolhoda Jahanbin, † Michela Festa, ‡ Anna Capasso, ‡ and Sonia Piacente* ,‡ Biotechnology Research Center and School of Pharmacy, Mashhad UniVersity of Medical Sciences, Mashhad, Iran, and Dipartimento di Scienze Farmaceutiche, UniVersita ` degli Studi di Salerno, Via Ponte Don Melillo, 84084 Fisciano, Salerno, Italy ReceiVed July 18, 2010 A new sesquiterpene coumarin, gumosin (1), two new sesquiterpene coumarin glycosides, gumosides A (2) and B (3), and 10 known compounds, namely, cauferoside (4), feselol (5), conferoside, ferilin, ferocaulidin, ligupersin A, conferol, and daucosterol, and the phenolic compounds acantrifoside E and 4-hydroxybenzoic acid 4-(6-O-sulfo)glucopyranoside, were isolated from a methanolic extract of Ferula gumosa roots. The structures of 1-3 were elucidated by spectroscopic data interpretation. The cytotoxic activity of the sesquiterpene coumarin derivatives was evaluated against a small panel of cancer cell lines. The genus Ferula (Apiaceae) comprises about 180 species, with most of these growing in Central Asia, the Middle East, and Central Europe. 1 Various plant parts of Ferula species such as the oleogum resin of F. assafetida, the roots of F. gumosa, and the leaves of F. latisecta have been used traditionally to treat stomachache, hysteria, infant colitis, and asthma. 2,3 The chemistry of the genus Ferula has been studied by many researchers, and it is well documented as being a good source of biologically active compounds such as sesquiterpene derivatives, 4-8 sulfur-containing compounds, 9,10 and coumarins. 6,11-14 There are also a few reports on polar secondary metabolites such as sesquiterpene coumarin glycosides from Ferula species. 15,16 Ferula gumosa Boiss. is an Iranian medicinal plant (the oleoresin of the plant called “Barijeh” in Persian) and has been used traditionally as a tonic, anticonvulsant, and emmenagogue herb. 2 Recent studies demonstrated some biological activities including anticonvulsant, 17 spasmolytic, 18 and antibacterial 19 effects from different parts of the plant. In addition, it has been reported that an extract of this plant could be useful for the alleviation of morphine- withdrawal syndrome. 20 In the present study, the methanolic extract of F. gumosa roots was investigated, which afforded a new sesquiterpene coumarin glycoside, gumosin (1), two new sesquiterpene coumarin glycosides, gumosides A and B (2, 3), along with cauferoside (4), 21 feselol (5), 13 conferoside, 21 ferilin, 22 ferocaulidin, 13 ligupersin A, 13 con- ferol, 12 and daucosterol, 23 and the phenolic compounds acantrifoside E 24 and 4-hydroxybenzoic acid 4-(6-O-sulfo)glucopyranoside. 25 The structures of these known compounds were elucidated by spectro- scopic data comparison to literature values. Sesquiterpene coumarin ethers (7-hydroxycoumarin deriva- tives) have been reported to possess various biological activies, including squalene-hopene cyclase inhibition, human rhinovirus coat protein inhibition, antibacterial activity, and NF-κB inhibi- tion. A potential cancer chemopreventive effect and cytotoxic activity are documented for farnesiferol C and for conferol, respectively. 26 Recently, the potential anticancer activity of the alcohol-soluble extract of Resina Ferulae, which is the dried resinous exudate obtained from the root and rhizomes of plants such as Ferula asafoedida L., F. conocaula Korovin, F. narthex Boiss., F. fetida Regel, F. fukanensis K.M. Shen, F. sinkiangensis K.M. Shen, and F. rigida Ten., has been reported. 27 Moreover, galbanic acid and other sesquiterpene coumarins isolated from Resina Ferulae have been reported to exert inhibitory activities against human cancer cell line proliferation such as A549 (human lung cancer), SK-OV-3 (ovary cancer), SK-HEL-2 (melanoma), and HCT-15 (colon can- cer). 27 On the basis of the above reports, the cytotoxic activities of sesquiterpene coumarins isolated from F. gumosa were evaluated against a small panel of cancer cell lines. The roots of F. gumosa were extracted with MeOH. The methanolic extract was subjected to column chromatography and purified by different chromatographic steps to yield three new compounds (1-3). Gumosin (1) was obtained as an amorphous, white solid, and its molecular formula, C 24 H 30 O 5 , was deduced by HRMALDITOFMS analysis (m/z 399.2168 [M + H] + , calcd for C 24 H 31 O 5 , 399.2172). Compound 1 was determined to be a sesquiterpene coumarin by the presence of diagnostic peaks in the 1 H NMR and 13 C NMR spectra (Table 1). The 13 C NMR spectrum of 1 displayed 24 carbon signals, with nine being typical of an umbelliferone skeleton 14 and 15 ascribable to a sesquiterpene moiety. 28 The 1 H NMR spectrum of 1 showed signals due to five aromatic protons at δ 6.27 (d, J ) 9.6 Hz), 6.92 (d, J ) 2.3 Hz), 6.97 (dd, J ) 8.2, 2.3 Hz), 7.56 (d, J ) 8.2 Hz), and 7.90 (d, J ) 9.6 Hz), typical of an umbelliferone moiety. For the sesquiterpene portion, signals corresponding to two olefinic protons at δ 5.73 (dd, J ) 10.8, 2.7 Hz) and 5.78 (dd, J ) 10.8, 1.3 Hz), a primary alcoholic function at δ 4.44 (dd, J ) 10.6, 3.7 Hz) and 4.21 (dd, J ) 10.6, 5.7 Hz), a secondary alcoholic function at δ 3.28 (dd, J ) 11.5, 4.4 Hz), and four tertiary methyl groups at δ 0.87, 1.04, 1.08, and 1.37, were evident. The HSQC experiment allowed the identification of 10 methines, of which five, at δ C 112.9 (C-3), 145.4 (C-4), 130.1 (C-5), 113.8 (C-6), and 101.7 (C-8), were characteristic for the umbelliferone unit, and five, at δ C 54.8, 58.3, 79.2, 127.9, and 136.2, were attributable to the sesquiterpene moiety. Further HSQC correlations were indicative of two aliphatic methylenes at δ C 27.3 and 37.0, an oxygenated methylene at δ C 67.3, characteristic for C-11′ usually involved in the linkage with the coumarin moiety, and four methyls at δ C 15.7, 16.3, 28.3, and 30.4. HMBC correlations between the proton signal at δ 1.37 (Me-12′) and the carbon resonance at δ 58.3 (C-9′) and between the protons at δ 4.44 and 4.21 attributable to CH 2 -11′ with the same carbon C-9′ revealed the location of a tertiary methyl group (Me-12′) at C-8′. The correlation of Me-12′ with the quaternary carbon at δ 70.6 allowed the occurrence of a tertiary alcoholic function to be deduced at C-8′. A further HMBC correlation between the singlet methyl at δ 1.04 (Me-15′) and the carbon resonances at δ 37.0 (C-1′), 37.8 (C-10′), and 58.3 (C-9′) * To whom correspondence should be addressed. (M.I.) Tel: ++985118823255. Fax: ++985118823251. E-mail: IranshahiM@ mums.ac.ir. (S.P.) Tel: ++39089969763. Fax: ++39089969602. E-mail: piacente@unisa.it. † Mashhad University of Medical Sciences. § These authors contributed equally to this work. ‡ Universita ` degli Studi di Salerno. J. Nat. Prod. 2010, 73, 1958–1962 1958 10.1021/np100487j  2010 American Chemical Society and American Society of Pharmacognosy Published on Web 10/20/2010