Guoli Huang

Chemical Constituents of Podocarpus wallichiana

Podocarpus species (Podocarpaceae) are a prolific source of diterpenoids including norand bis-norditerpenoid dilactone groups, flavonoids, biflavonoids, phenolics, lignans, and steroids, some of which have different activities such as antitumor, antioxidant, antimicrobial, anti-inflammatory, plant growth inhibitory, and cathepsin inhibitory effects [1–3]. P. wallichiana is distributed in Vietnam, Burma, India, and Yunnan of southwestern China [4]. Previously, there has been no phytochemical study on the plant. In our search for naturally occurring bioactive natural products from medicinal plants in Yunnan of China, we investigated the plant. P. wallichiana was collected from Xishuangbanna of Yunnan, China in October, 2009. The air-dried leaves (6.5 kg) were exhaustively extracted with MeOH. Water (3.5 L) was added to the MeOH extract, and the resulting solution was partitioned with EtOAc and n-BuOH successively (six times, each 3.0 L). The EtOAc extract (440 g) was separated on a silica gel column and eluting with petroleum ether–EtOAc (1:0 to 0:1) to afford eight fractions A–H. Fraction D (16 g) was recrystallized from EtOAc to obtain compound 1 (14 mg). Fraction F (28 g) was subjected to repeated CC, first on silica gel (CHCl3–acetone 1:0–0:1) and then on Sephadex LH-20 (MeOH–CHCl3 2:3) to afford compounds 2 (23 mg), 3 (40 mg), and 4 (30 mg). All compounds were identified by spectroscopic methods, including NMR and mass spectrometry. NMR spectra were acquired on a Bruker DRX-500 spectrometer operating at 500 (1H) and 125 MHz (13C and DEPT). Sugiol (1), colorless crystals, C20H28O2. EI-MS m/z 300 [M]+ (65), 285 (100), 243 (30). 1H NMR (CDCl3, , ppm, J/Hz): 7.88 (1H, s, H-14), 6.71 (1H, s, H-11), 3.20 (1H, sep, J = 6.2, H-15), 2.64 (1H, dd, J = 18.4, 4.5, H-6a), 2.59 (1H, dd, J = 18.4, 13.5, H-6b), 2.19 (1H, m, H-1a), 1.84 (1H, dd, J = 14.0, 4.5, H-5), 1.76 (1H, m, H-2a), 1.65 (1H, m, H-2b), 1.50 (2H, m, H-3a, 1b), 1.26 (1H, m, H-3b), 1.24 (1H, d, J = 7.0, H-16), 1.22 (3H, d, J = 7.0, H-17), 1.21 (3H, s, H-20), 0.98 (3H, s, H-19), 0.92 (3H, s, H-18). 13C NMR (CDCl3, , ppm): 199.2 (s, C-7), 159.7 (s, C-12), 156.5 (s, C-9), 133.2 (s, C-13), 126.4 (d, C-14), 123.7 (s, C-8), 109.5 (d, C-11), 49.5 (d, C-5), 41.4 (t, C-3), 37.8 (t, C-1), 37.8 (s, C-10), 36.0 (t, C-6), 33.2 (s, C-4), 32.5 (q, C-18), 26.6 (d, C-20), 23.1 (q, C-15), 22.4 (q, C-16), 22.3 (q, C-17), 21.3 (q, C-19), 18.9 (t, C-2) [5]. Vanillic acid (2) [6], p-hydroxybenzoic acid (3) [7], and 7-ketositosterol (4) [8] were identified by the analysis of their 1H NMR and 13C NMR spectral data and comparison with the literature. All the compounds were isolated from the plant for the first time.

Constituents of Lithocarpus fohaiensis

column, eluting with CHCl3–MeOH (3:2) to provide four major fractions (B1–B4). Compounds 1 (56 mg) and 6 (915 mg) were obtained from Fr. B1 (1.5 g) on a silica gel column, eluting with petroleum ether–EtOAc (10:1), and then purified on Sephadex LH-20 with CHCl3–MeOH (3:2). Fraction B2 (1.0 g) was purified on a silica gel column (CHCl3–MeOH, 100:1) and then isolated on Sephadex LH-20 with CHCl3–MeOH (3:2) to furnish 15 (17 mg). Compound 10 (15 mg) was obtained from Fr. B3 (54 mg) on silica gel with CHCl3–acetone (50:1) and further purified on Sephadex LH-20, eluting with CHCl3–MeOH (3:2). Fraction B4 (55 mg) was subjected to silica gel column chromatography, eluting with petroleum ether–EtOAc (5:1), and then fractionated on Sephadex LH-20 with CHCl3–MeOH (3:2) to give 7 (8 mg). Fraction 4 (4.9 g) was submitted to a Sephadex LH-20 column eluting with CHCl3–MeOH (3:2) to give four fractions (C1–C4). Compound 11 (4 mg) was obtained from Fr. C1 (89 mg) on a silica gel column, eluting with petroleum ether–EtOAc (5:1), and purified on a Sephadex LH-20 column with CHCl3–MeOH (3:2). Fraction C2 (120 mg) was separated on a silica gel column with CHCl3–acetone (50:1) to yield 3 (70 mg). Compounds 2 (6 mg) and 4 (18 mg) were obtained from Fr. C3 (128 mg) by silica gel chromatography with CHCl3–acetone (50:1) and further purified on Sephadex LH-20 with CHCl3–MeOH (3:2). Compound 5 (6 mg) was obtained from Fr. C4 (89 mg) on a silica gel column, eluting with petroleum ether–EtOAc (5:1), and then purified on Sephadex LH-20 with CHCl3–MeOH (3:2). Fraction 5 (11.4 g) was applied to a Sephadex LH-20 column with CHCl3–MeOH (3:2) to provide four major fractions (D1–D4). Compound 12 (15 mg) was obtained from Fr. D1 (1.2 g) on a silica gel column, eluting with petroleum ether–EtOAc (2:1), and then purified on Sephadex LH-20 with CHCl3–MeOH (3:2). Fraction D2 (1.5 g) was purified on a silica gel column (petroleum ether–EtOAc, 2:1) and then isolated on a Sephadex LH-20 column with

A new abietane mono-norditerpenoid from Podocarpus nagi

Abstract A new abietane mono-norditerpenoid, nagiol A (1), along with three known diterpenoids were isolated from the leaves of Podocarpus nagi. Their structures were elucidated by means of extensive spectroscopic analysis. This is the first report of abietane mono-norditerpenoid separated from plant of the genus Podocarpus. Compound 1 was assessed for its cytotoxicity against five human tumour lines (HL-60, SMMC-7721, A-549, MCF-7 and SW-480), and the result showed that it had no activity.

Constituents of the Glandular Trichome Exudate on the Leaves of Laggera pterodonta

Glandular trichomes are microorgans located on the surface of the stems, leaves, flowers, and fruits of plants that produce secondary metabolites such as terpenoids, phenylpropanoids, polyketides, and fatty acid derivatives [1, 2], which are related to a plant s self-protection system, e.g., they serve as antifeedants, antifungals, antibiotics, or for UV protection [3–5]. However, the understanding of the chemistry and physiological roles of glandular trichome exudate is not enough. The genus Laggera, belonging to the Asteraceae family, has about 20 species, which are distributed mainly in tropical Africa and Southeastern Asia [6]. Extensive studies of Laggera species have led to the identification of some compounds, including sesquiterpenes, monoterpenes, flavonoids, and cylitols [7]. L. pterodonta (DC.) Sch.Bip. ex Oliv. is distributed widely in Southwestern China, especially in Yunnan and Sichuan Provinces. The plant is traditionally employed as a medicine because it has antiinflammatory and antibacterial properties and has been used as a cure for angina, bronchitis, influenza, and malaria [8]. Previous studies on the constituents of L. pterodonta disclosed the presence of sesquiterpenoids, flavones, steroids, coumarins, triterpenes, and phenolic acids, and the plant has been found to possess antileukemic activity, as well as expectorant and antibronchitis effects [9–11], but there has been no report on the glandular trichome exudate of the plant. Here we investigate the glandular trichome exudates on the leaves of L. pterodonta. The leaves of L. pterodonta were collected from Kunming, Yunnan Province, P. R. China, in September, 2013 and identified by Shi-shun Zhou, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences. A voucher specimen of this collection (No. 130413) has been deposited at the Herbarium of Yunnan Normal University, Kunming, China. Fresh young leaves (fresh weight 600 g, ca. 3.0 cm wide and 8 cm long) were quickly (~ 2 s) rinsed once in a beaker containing CHCl3 (total volume 500 mL), and the CHCl3 solution was concentrated to dryness under reduced pressure. The CHCl3 extract (2 g) was subjected to silica gel chromatography, eluting with a gradient of petroleum ether–EtOAc (20:1 to 1:4), to offer three fractions. Fraction A (100 mg) was further isolated by silica gel chromatography (petroleum ether–acetone 7:3, v/v) to yield 1 (30 mg). Fraction B (1.3 g) was separated by column chromatography (silica gel, CHCl3–acetone 30:1 to 15:1) to give 2 (50 mg) and 3 (800 mg). Fraction C (100 mg) was purified on a silica gel column (CHCl3–acetone 30:1 to 10:1) and then on a Sephadex LH-20 column eluted with CHCl3–MeOH (3:2) to afford 4 (25 mg) and 5 (12 mg). All compounds were identified by means of spectroscopic methods as well as comparison with literature data, including NMR [NMR spectra were acquired on a Bruker DRX-500 spectrometer operating at 500 (1H) and 125 MHz (13C and DEPT)].

Synthesis and biological evaluation of nigranoic acid esters as novel human neutrophil elastase inhibitors

Human neutrophil elastase (HNE) has been implicated as a major contributor in the pathogenesis of diseases, such as lung disorders and other inflammatory diseases. A series of 12 new nigranoic acid esters were regioselectively synthesised in good yields and evaluated for HNE inhibitory activity. Nigranoic acid exhibited significant inhibitory activity against HNE with the IC50 value of 3.77 μM, and six esters displayed considerable inhibitory effects on HNE with IC50 values in the range of 2.61–8.95 μM. The nigranoic acid esters having phenyls substituted with bromine and trimethoxyls (3h and 3b) showed stronger inhibitory activity on HNE than nigranoic acid.

Ammonium Chloride–Catalyzed One-Pot Synthesis of 4(3H)-Quinazolinones Under Solvent-Free Conditions

Abstract Ammonium chloride, which is a very inexpensive and readily available reagent, can efficiently catalyze three-component, one-pot condensation reactions of 2-amino-benzoic acid esters, ortho esters, and aromatic amines to afford the corresponding 4(3H)-quinazolinones in good to excellent yields under solvent-free conditions. GRAPHICAL ABSTRACT