C. L. Kao

Isoquinoline Alkaloids from Michelia fuscata

Two new isoquinoline alkaloids, fuscatine A (1) and fuscatine B (2), along with 21 compounds including eight isoquinoline alkaloids, northalifoline (3), thalifoline (4), corydaldine (5), N-methylcorydaldine (6), (6,7-dimethoxyisoquinolinyl)-(4′-methoxyphenyl)-methanone (7),(6,7-dimethoxyisoquinolinyl)-(4′-hydroxyphenyl)-methanone (8), liriodenine (9), and corydine (10); two steroids, β-sitosterone and stigmasterone; six benzenoids, p-hydroxybenzaldehyde, p-hydroxybenzoic acid, 3,4-dimethoxybenzoic acid, methylparaben, syringic acid, and coniferyl aldehyde; one quinone 2,6-dimethoxy-p-benzoquinone, and one sesquiterpene, caryophyllene oxide, are isolated from the stems of Michelia fuscata (Magnoliaceae). These compounds were characterized and identified by physical and spectral analysis.

Cinnapine, a New Pyridine Alkaloid from Cinnamomum Philippinense

Cinnapine (1), a new pyridine alkaloid, has been isolated from the roots of Cinnamomum philippinense (Lauraceae). The structure was characterized and identified by spectral analysis.

Chemical Constituents of Cultured Soft Coral Sinularia flexibilis

Diterpenes of the cembrane type are some of the most frequently encountered metabolites in soft corals of the order Alcyonacean [1]. Of particular interest, cembrane-type diterpenoids have been reported to display a variety of biological activities, including antitumor and antifouling activities [2]. Marine-derived compounds obtained from soft corals are believed to yield many potential candidate compounds for treating inflammatory disease, particularly for treating pain [3–6]. The natural marine compound sinularin has been well studied and was shown by Weinheimer et al. in 1977 to have anticancer activity against the human epidermoid carcinoma cell line and the murine P388 lymphocytic leukemia cell line from the soft coral Sinularia flexibilis [7]. As part of our continuing investigation of the phytochemical and bioactive compounds of S. flexibilis, five cembranoids, isosinulaflexiolide K (1) [8], sinulaflexiolide K (2) [9], sandensolide (3) [10], sinularin (4) [7] and dendronpholide F (5) [11] were obtained by systematic extraction and isolation from this soft coral. All of these known compounds were identified by direct comparison with authentic sample (TLC, UV, IR, ESI-MS and NMR) and the literature [8–11]. Compounds 1–3, 5 were found for the first time from this cultured soft coral. The one light yellow cultured soft corals S. flexibilis was initially collected from the wild and subsequently grown for 8 years in an 80 ton cultivation tank located in the National Museum of Marine Biology & Aquarium. The tank was a flowthrough seawater system, and deliberate feeding was not required. The specimen was collected by hand in January 2013, frozen immediately, and kept frozen until extraction. This soft coral was identified by Chang-Feng Dai (Institute of Oceanography, National Taiwan University). A voucher specimen was deposited in the National Museum of Marine Biology & Aquarium (2013CSC-2). The frozen S. flexibilis (4.2 kg, wet weight) was freeze-dried, and the resulting material (450 g) was minced and extracted exhaustively with EtOAc (6 2 L). The EtOAc extract was evaporated under reduced pressure to afford a residue (30.5 g), and the residue was subjected to column chromatography on silica gel using n-hexane, an n-hexane–EtOAc mixture of increasing polarity, and finally pure acetone to yield 13 fractions. Part of fraction 11 was subjected to silica gel chromatography by eluting with n-hexane–EtOAc (1:2 to 1:3) enriched with EtOAc to furnish four further fractions (11-1–11-4). Part of fraction 11-2 (3.2 g) was subjected to silica gel chromatography by eluting with CH2Cl2–MeOH (100:1) enriched gradually with acetone to furnish four fractions (11-2-1–11-2-4). Fractions 11-2-1 (0.4 g) were subjected to further silica gel column chromatography and purified by preparative TLC (CH2Cl2–MeOH, 200:1) to yield isosinulaflexiolide K (1, 5 mg) and sinulaflexiolide K (2, 2mg). Fractions 11-2-2 (1.2 g) were subjected to further silica gel column chromatography and purified by preparative TLC (CH2Cl2–MeOH, 100:1) to yield sinularin (4, 203 mg) and sandensolide (3, 127 mg). Fractions 11-2-3 (0.2 g) were subjected to further silica gel column chromatography and purified by preparative TLC (CH2Cl2–MeOH, 100:1) to yield sandensolide (3, 25 mg). Fractions 11-2-4 (0.3 g) were subjected to further silica gel column chromatography and purified by preparative TLC (CH2Cl2–MeOH, 200:1) to yield dendronpholide F (5, 7 mg).

Two New Phenylalkanoids from the Rhizomes of Zingiber officinale

Two new phenylalkanoids, 5-hydroxy-1-(4′,5′-dihydroxy-3′-methoxyphenyl)dodecan-3-one (1) and 1-(4′,5′-dihydroxy-3′-methoxyphenyl)dodec-4-en-3-one (2), were isolated from the rhizomes of Chinese ginger (Zingiber officinale Roscoe (Zingiberaceae)). The structures of the two new phenylalkanoids were elucidated by chemical and physical evidence.

Chemical Constituents of the Seed of Aquilaria sinensis

The genus Aquilaria (Thymelaeaceae) is widely distributed in Asia. Aquilaria sinensis (Lour.) Spreng. is of particular interest economically because it is the principal source of agarwood, one of the most valuable forest products currently traded internationally [1]. Aquilaria sinensis is the only plant resource in China for agarwood, which is also called Chinese eaglewood, to distinguish it from agarwood of other species, such as A. agallocha or A. malaccensis. Previous phytochemical investigation on Chinese eaglewood revealed characteristic sesquiterpenes and chromone derivatives [2–10], but little is known about the chemical constituents of the seed. From data of interrelated studies, agarwood has significant anticancer activities [11], analgesic and anti-inflammatory activities [12], and anti-depression activities [13]. These observations provide useful information for chemopreventive drug design. The MeOH extract of its seed was subjected to solvent partitioning and chromatographic separation to afford 12 pure substances. The chemical constituents of the seed of A. sinensis were separated by column chromatography. Seven compounds, including four flavonoids, 5-hydroxy4 ,7-dimethoxyflavone (1) [14], luteolin-7,3 ,4 -tri-O-methyl ether (2) [15], 5,3 -dihydroxy-7,4 -dimethoxyflavone (3) [16], and persicogenin (4) [17], and three lignans, (+)-syringaresinol (5) [18], (+)-dia-syringaresinol (6) [19], and (+)-epi-syringaresinol (7) [19], were isolated from the seed of A. sinensis. The specimen of A. sinensis was collected from Guansi Township, Hsinchu County, Taiwan in May, 2007. A voucher specimen was identified by Prof. Fu-Yuan Lu (Department of Forestry and Natural Resources, College of Agriculture, National Chiayi University) and was deposited in the School of Medical and Health Sciences, Fooyin University, Kaohsiung, Taiwan. The seeds (0.4 kg) of A. sinensis were chipped and air dried and extracted repeatedly with MeOH (3 L 5) at room temperature. The combined MeOH extracts (24.3 g) were then evaporated and further separated into five fractions by column chromatography on silica gel (2.5 kg, 70–230 mesh) with gradients of n-hexane–CH2Cl2–acetone–MeOH. Part of fraction 1 (3.1 g) was subjected to silica gel chromatography by eluting with n-hexane–acetone (50:1) and enriched with acetone to furnish three further fractions (1-1–1-3). Fraction 1-1 (0.8 g) was further purified on a silica gel column using n-hexane–acetone mixtures to obtain 5-hydroxy-4 ,7-dimethoxyflavonoid (1, 6.2 mg). Part of fraction 1-2 (1.1 g) was subjected to silica gel chromatography by eluting with n-hexane–acetone (50:1) and enriched gradually with acetone to furnish four fractions (1-2-1–1-2-4). Fraction 1-2-2 (0.4 g) was further purified on a silica gel column using n-hexane–acetone mixtures to yielded luteolin-7,3 ,4 -trimethyl ether (2, 1.2 mg) and 5,3 -dihydroxy-7,4 -dimethoxyflavone (3, 2.4 mg). Part of fraction 2 (6.3 g) was subjected to silica gel chromatography by eluting with n-hexane–acetone (40:1) and enriched with acetone to furnish three further fractions (2-1–2-3). Fraction 2-2 (1.3 g) was further purified on a silica gel column using n-hexane–acetone mixtures to obtain persicogenin (4, 4.1 mg). Part of fraction 3 (5.8 g) was subjected to silica gel chromatography by eluting with CH2Cl2–MeOH (100:1) and enriched with MeOH to furnish three fractions (3-1–3-3). Fractions 3-2 (0.4 g) were subjected to further silica gel column chromatography and purified by preparative TLC (CH2Cl2–MeOH [25:1]) to yield (+)-syringaresinol (5, 5 mg), (+)-dia-syringaresinol (6, 3 mg), and (+)-epi-syringaresinol (7, 2 mg).

Chemical Constituents of the Leaves of Michelia figo

Species belonging to the genus Michelia are arboreous plants, growing in temperate zones of oriental India, southern China, Malaysia, and Indonesia. The species most utilized is Michelia champaca: its cortex and seeds are used as febrifuge and tonic-aromatic; the roots are employed as emmenagogue, the leaves as astringent, the gemmae in the treatment of hemorrhage, and the flowers and fruits are believed to possess curative properties in enteritis [1]. The less known species, M. figo, is used as ornamental plants and to obtain essences [1]. M. figo is an evergreen medium shrub, commonly called banana shrub, because of the heavy, sweet fragrant banana scent of its purple flowers. The plant is also known in Indian folk medicine as a remedy against hypertension [2]. To further understand the chemotaxonomy of the Michelia species [3–7], M. figo was chosen for phytochemical investigation. The chemical constituents of the leaves of this plant have not yet been reported. The compounds derived from the leaves include three alkaloids, (–)-nuciferine (1) [8], (–)-anonaine (2) [9], and N-methylcorydaldine (3) [10]; two steroids, -sitostenone (4) [9] and stigmasta-4,22-dien-3-one (5) [9]; four benzenoids, p-hydroxybenzaldehyde (6) [10], p-hydroxybenzoic acid (7) [11], methylparaben (8) [11], and vanillin (9) [11]; six chlorophylls, pheophytin a (10) [12], pheophorbide a (11) [12], pheophytin b (12) [13], pheophorbide b (13) [13], aristophyll-C (14) [14], 132-hydroxy-(132-S)pheophytin a (15) [15]; and one sesquiterpene lactone, 11,13-dehydrolanuginolide (16) [16]. All of these known compounds were obtained for the first time from the leaves of this plant and were identified by direct comparison with authentic samples (TLC, UV, IR, ESI-MS and NMR) and the literature [8–16]. The leaves of M. figo (Lour.) Spreng. were collected from Chiayi County, Taiwan, May 2011. Plant material was identified by Prof. Fu-Yuan Lu (Department of Forestry and Natural Resources, College of Agriculture, National Chiayi University). A voucher specimen (Michelia 5) was deposited in the School of Medicinal and Health Sciences, Fooyin University, Kaohsiung City, Taiwan. The air-dried leaves of M. figo (4.8 kg) were extracted with MeOH (6 L 4) at room temperature, and a MeOH extract (121.6 g) was obtained upon concentration under reduced pressure. The MeOH extract, suspended in H2O (1 L), was partitioned with CH2Cl2 (3 L 5) to give fractions soluble in CH2Cl2 (67.9 g) and H2O. The CH2Cl2-soluble fraction was chromatographed over silica gel (950 g, 70–230 mesh) using n-hexane–EtOAc–MeOH mixtures as eluents to give five fractions. Part of fraction 1 (8.24 g) was subjected to silica gel chromatography by eluting with n-hexane–EtOAc (60:1) and enriched gradually with EtOAc to furnish five fractions (1-1–1-5). Fraction 1-2 (3.11 g) was further purified on a silica gel column using n-hexane–EtOAc mixtures to obtain (12 mg) and 5 (6 mg). Part of fraction 2 (11.78 g) was subjected to silica gel chromatography by eluting with n-hexane–EtOAc (60:1) and enriched gradually with EtOAc to furnish five fractions (2-1–2-5). Fraction 2-1 (2.78 g) was further purified on a silica gel column using n-hexane–EtOAc mixtures to obtain 10 (3 mg) and 11 (4 mg). Fraction 2-2 (2.17 g) was further purified on a silica gel column using n-hexane–EtOAc mixtures to obtain 12 (1 mg) and 13 (2 mg). Fraction 2-3 (2.86 g) was further purified on a silica gel column using n-hexane–EtOAc mixtures to obtain 14 (13 mg) and 15 (9 mg). Fraction 2-4 (1.55 g) was further purified on a silica gel column using n-hexane–EtOAc mixtures to obtain 16 (18 mg). Part of fraction 3 (16.97 g) was subjected to silica gel chromatography by eluting with n-hexane–EtOAc (40:1) and enriched with EtOAc to furnish six further fractions (3-1–3-6). Fraction 3-3 (4.24 g) was further purified on a silica

A New Dimeric Ionone from the Unripe Fruits of Capsicum annuum var. conoides

Red pepper, Capsicum annuum (Solanaceae), is used as a spice all over the world. Red pepper is studied actively because its pungent principal component, capsaicin, has a dietary effect, analgesic activity, and antioxidant activity [1]. The pungent principal component of red peppers is a group of acid amides of vanillylamine and C8 to C13 fatty acids, which are known generally as capsaicin [2]. More than 16 other capsaicinoids have been found as minor components [3]. Numerous studies have been done on the red pepper fruit, but there are few studies on stems [2–4]. Previously, we isolated 19 compounds, including ten amides, four steroids, and six benzenoids from the stems of this plant [5]. We also isolated 17 compounds, including three chlorophylls, six steroids, one ionone, and seven benzenoids from the unripe fruits of this plant [6]. To further understand the chemotaxonomy and to continue searching for biologically and chemically novel agents from Solanaceous plants, the unripe fruits of C. annuum L. var. conoides (Mill.) Irish were chosen for further phytochemical investigation. In this paper, we report the isolation and structural elucidation of this new dimeric ionone. Conoidol (1) was obtained as a white amorphous powder from CHCl3. Its molecular formula was deduced as C27H36O5 by HR-ESI-MS (m/z 463.2458 ([M + Na]+; calcd 463.2460)). The UV spectrum of conoidol contained absorption bands typical of the -ionone derivatives [7]. The IR spectrum of conoidol showed characteristic absorption bands due to the presence of hydroxyl (3400 cm–1) and carbonyl (1665 cm–1) groups. The 1H NMR spectrum of conoidol contained two ethylenic protons indicated by two doublets each for 1H at 6.83 (2H, d, J = 16.0 Hz) and 6.47 (2H, d, J = 16.0 Hz), and their spin coupling pattern indicates the presence of one trans-disubstituted ethylene moiety in the molecule. It also represented one hydroxy proton at 5.70 (1H, s), three methine protons at 5.96 (2H, s) and 4.34 (1H, br.s), and four methylene protons at 2.34 (2H, d, J = 17.0 Hz) and 2.50 (2H, d, J = 17.0 Hz). The compound also illustrated four characteristic singlets for 24 protons at 2.31 (6H, s), 1.88 (6H, br.d, J = 1.0 Hz), 1.11 (6H, s), and 1.03 (6H, s). The 13C NMR and DEPT experiments of 1 showed 14 resonance lines consisting of four methyls, one methylene, four methines, and five quaternary carbons. The structure of conoidol was also confirmed by 2D NMR experiments. A COSY correlation was observed between H-1 and H-2 , and between H-1 and H-2 . The HETCOR experiment showed that the carbon signals at 49.3 for C-6 (C-6 ), 127.2 for C-2 (C-2 ), 130.6 for C-2 (C-2 ), and 145.5 for C-1 (C-1 ) were correlated to the proton signals at 2.34 and 2.50 for H-6 (H-6 ), 5.96 for H-2 (H-2 ), 6.47 for H-2 (H-2 ), and 6.83 for H-1 (H-1 ), respectively. Thus, 1 is a dimer of (S)-dehydrovomifoliol [8], which was further confirmed by NOESY and HMBC experiments.

Chemical Constituents of the Flowers of Michelia alba

Michelaine (1), (–)-anonaine, (–)-norushinsunine, (–)-ushinsunine, (–)-N-acetylanonaine, liriodenine, atherospermidine, (+)-syringaresinol, N-trans-feruloyltyramine, p-hydroxybenzaldehyde, vanillin, vanillic acid, syringic acid, coniferyl aldehyde, syringin, scopoletin, 4-acetonyl-3,5-dimethoxy-p-quinol, β-sitostenone, and stigmasta-4,22-dien-3-one were isolated from the flowers of Michelia alba (Magnoliaceae). Among them, michelaine (1) is a new 4,5-dioxoaporphine compound. The structures of these compounds were characterized and identified by spectral analyses.

Secondary Metabolites from the Stems of Ilex cornuta

Ilex (Aquifoliaceae) species are distributed widely in the People s Republic of China, and some are used extensively in folk medicine. For example, I. rotunda is an antipyretic and antidote and is used for the treatment of the common cold, tonsillitis, and stomach and intestinal ulcers. I. pubescens is used for the treatment of coronary disease, myocardial infarction, dysentery, and erysipelas. I. cornuta and I. latifolia are used for the treatment of headache, toothache, bloodshot eyes, and tinnitus [1]. Previous studies on the Ilex genus have led to the isolation of triterpenes, triterpene glycosides [2], hemiterpene glycosides [3], phenolic compounds [4], and flavonoids [5]. In the present study on the chemical components of the stems of I. cornuta, five compounds were isolated. A methanolic extract of the stems of I. cornuta was concentrated to obtain a residue, and it was partitioned between CH2Cl2 and H2O. The aqueous layer was extracted with n-BuOH. The n-BuOH layer was concentrated and subjected to chromatography. As a result, five compounds, including a dihydroberberine alkaloid, oxyberberine (1) [6], and four protoberberine alkaloids, berberine (2) [7], palmatine (3) [8], jatrorrhizine (4) [9], and columbamine (5) [10], were isolated. All of these compounds were isolated for the first time from this source. The stems of I. cornuta were collected from Kaohsiung, Taiwan, October 2006. Plant material was identified by Dr. Fu-Yuan Lu (Department of Forestry and Natural Resources, College of Agriculture, National Chiayi University). A voucher specimen was deposited in the School of Medical and Health Sciences, Fooyin University, Kaohsiung, Taiwan. The air-dried stems of I. cornuta (2.3 kg) were extracted with MeOH (10 L 5) at room temperature, and a MeOH extract was obtained upon concentration under reduced pressure. The combined MeOH extracts were evaporated and partitioned to yield CH2Cl2 and aqueous extracts. The aqueous extracts were evaporated and extracted with n-BuOH to give an n-BuOH layer and an aqueous layer. The n-BuOH layer (72.8 g) was chromatographed over silica gel (500 g, 70–230 mesh) using CH2Cl2–MeOH mixtures as the eluent to produce five fractions. Part of fraction 1 (16.7 g) was subjected to silica gel chromatography, eluted with n-hexane–CH2Cl2 (1:1), and enriched gradually with CH2Cl2, to furnish five fractions (1-1–1-5). Fraction 1-4 (1.3 g) was further purified on a silica gel column using n-hexane–CH2Cl2 mixtures to obtain oxyberberine (1) (7 mg). Part of fraction 2 (12.4 g) was subjected to silica gel chromatography, eluted with CH2Cl2–MeOH (8:1), and enriched with MeOH to furnish five further fractions (2-1–2-5). Fraction 2-2 (3.2 g) was further purified on a silica gel column using CH2Cl2–MeOH mixtures to obtain berberine (2) (24.9 mg). Part of fraction 3 (17.4 g) was subjected to silica gel chromatography, eluted with CH2Cl2–MeOH (7:1), and enriched with MeOH to furnish five further fractions (3-1–3-5). Fraction 3-4 (4.5 g) was further purified on a silica gel column using CH2Cl2–MeOH mixtures to obtain palmatine (3) (31.2 mg). Part of fraction 4 (12.9 g) was subjected to silica gel chromatography, eluted with CH2Cl2–MeOH (7:1), and enriched with MeOH to furnish four further fractions (4-1–4-4). Fraction 4-2 (3.3 g) was further purified on a silica gel column using CH2Cl2–MeOH mixtures to obtain jatrorrhizine (4) (3 mg). Part of fraction 5 (22.3 g) was subjected to silica gel chromatography, eluted with CH2Cl2–MeOH (6:1), and enriched with MeOH to furnish three further fractions (5-1–5-3). Fraction 5-2 (2.3 g) was further purified on a silica gel column using CH2Cl2–MeOH mixtures to obtain columbamine (5) (13 mg).

Chemical Constituents of the Roots of Michelia champaca

Champacaine A, 7-methoxy-1,2,3,4-tetrahydroisoquinolin-1-one, thalifoline, N-methylcorydaldine, liriodenine, 11,13-dehydrolanuginolide, (+)-syringaresinol, (+)-epi-syringaresinol, (+)-dia-syringaresinol, (+)-sesamin, N-trans-feruloyltyramine, syringic acid, syringaldehyde, 2,6-dimethoxy-p-benzoquinone, β-sitostenone, and stigmasta-4,22-dien-3-one were isolated from the roots of Michelia champaca L. (Magnoliaceae). Among them, champacaine A is a new aristolactam alkaloid. The structures of these compounds were characterized and identified by spectral analyses.