New Bisabolane‐Type Sesquiterpenes from the Aerial Parts of Lippia dulcis.

Abstract

Lippia dulcis TREV. is an intensely sweet herb endemic to tropical America and the leaves are used as a traditional medicine for the treatment of coughs and bronchitis. 1) A study on the constituent of the leaves and flowers of this herb was made by Compadre et al., 2) Kaneda et al. 3) and Abe et al., 4) and two sweet bisabolane-type sesquiterpenes, ()-her-nandulcin (1) and ()-4b-hydroxyhernandulcin, two non-sweet bisabolane-type sesquiterpenes, ()-epihernandulcin (2) and ()-anymol, 6-methyl-5-heptene-2-one, and four phenylethanoid glycoside esters, acteoside, isoacteoside, martynoside and diacetylmartynoside were isolated. In the course of our studies on Verbenaceae plants and natural antioxidants, we examined the constituents of the MeOH extract of the aerial parts of L. dulcis. The present paper describes the isolation and structure elucidation of two new bis-abolane-type sesquiterpenes (3, 4) along with five known flavonoids (5-9), three known phenylethanoid glycosides (10-12) and two known iridoid glucosides (13, 14), as well as the anioxidative activity of eight phenolic compounds (5-12). The MeOH extract of the aerial parts of L. dulcis was successively subjected to Diaion HP20, silica gel, Sephadex LH20 and Chromatorex ODS column chromatographies as well as HPLC on ODS to afford twelve compounds (3-14). Compounds 5-14 were identified as cirsimaritin (5), 5) salvigenin (6), 6) eupatorin (7), 7) 5-hydroxy-6,7,3,4-tetra-methoxyflavone (8), 8) 5,3-dihydroxy-6,7,4,5-tetramethoxy-flavone (9), 9) decaffeoylverbascoside (10), 10) acteoside (11), 11) isoacteoside (12), 12) 8-epiloganin (13) 13) and lamiide (14), 14) respectively, based on their physical and spectral data. Compounds 3 and 4 were obtained as a colorless oil. In the FAB-MS, 3 and 4 exhibited an [MH] ion peak at m/z 253; the high-resolution (HR) FAB-MS indicated the molecular formula of both compounds to be C 15 H 24 O 3. The 1 H-NMR spectra of 3 and 4 showed signals due to four tertiary methyl groups (d 1.98, 1.272, 1.19 in 3; d 1.97, 1.252, 1.16 in 4) and three olefinic protons [d 5.84 (q like, J1.0 Hz), 5.76 (ddd, J6.0, 8.0, 15.5 Hz), 5.67 (d, 15.5 Hz) in 3; d 5.81 (q like, J1.0 Hz), 5.69 (ddd, J6.5, 7.5, 15.5 Hz), 5.60 (d, J15.5 Hz) in 4], two of which were trans-coupling each other. The 13 C-NMR spectra of 3 and 4 showed 15 carbon signals, including one carbonyl carbon (d 205.9 in 3; d 204.4 in 4), four olefinic carbons (d 166.8, 142.6, 127.8, 123.0 in 3; d 166.2, 142.4, 127.9, 123.5 in 4), and two oxygenated quaternary carbons (d 75.8, 71.2 in 3; d 75.5, 71.2 in 4). These 1 Hand 13 C-NMR signals were assigned with the aid of 1 H-1 H correlation spectroscopy (COSY), heteronuclear multiple quantum coherence (HMQC) and heteronuclear multiple bond correlation (HMBC) and nuclear Overhauser and exchange spectroscopy (NOESY) spectra; 3 and 4 were determined to possess the same planar structure as illustrated in Fig. 1. Kinghorn and his coworkers 2,3) reported that the 13 C-NMR chemical shifts for C-6, C-2, and C-8 in 1 and 2 showed the difference owin...

A new phenylethanoid glycoside from the fruits of Callicarpa japonica Thunb. var. luxurians Rehd.

“…4). The strong antioxidative activity of 5 by this method was previously reported [11]. The radicalscavenging effect of 1-6 on the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) was also examined.…”

“…The value of control represents 100% lipid peroxidation. Astrisk previous report [11] α-tocopherol L-cysteine Assay of scavenging effect on DPPH…”

DPPH radical-scavenging effect on some constituents from the aerial parts of Lippia triphylla

“…Caffeic acid and ferulic acid were purchased from Nacakai Tesque, Inc. (Kyoto). Decaffeoylverbascoside was isolated from the aerial parts of L. dulcis [39].…”

Protective effect of cirsimaritin against streptozotocin-induced apoptosis in pancreatic beta cells

“…[16] Cirsimaritin is flavonoid isolated from Cirsium spp. [17] and exhibits a variety of pharmacological activities including anti-inflammatory, [18] antibacterial, [19,20] antioxidant, [21][22][23][24] anti-anxiety, [25] antispasmodic, [26,27] antiproteinuria, [28] bacterial drug resistance, [29] cyclooxygenase-1 inhibitory, [18] renal protective [30,31] and melanogenic activities. [32] In addition, it has been suggested to have cytotoxic activity against the following human tumour cell lines: gallbladder carcinoma, GBC-SD and GBCSD18H; gastric carcinoma, BGC-823; hepatoma, SMMC-7721.…”