Li-Yuan Yang

Ten-Membered Lactones from Phomopsis sp., an Endophytic Fungus of Azadirachta indica

Four new 10-membered lactones ( 1- 4) and one known one ( 5) were isolated from the broth extract of an endophytic fungus, Phomopsis sp., obtained from the stem of Azadirachta indica. Their structures were assigned by analysis of spectroscopic data, and the structures of 1 and 4 were also confirmed by X-ray analysis. Compounds 1- 5 were tested for antifungal activity against several plant pathogens. Compound 4 demonstrated antifungal activity in the MIC value range 31.25-500 microg/mL.

Two New Solanapyrone Analogues from the Endophytic Fungus Nigrospora sp. YB-141 of Azadirachta indica

Two new solanapyrone analogues, solanapyrones N and O (1 and 2, resp.), and three known compounds, solanapyrone C (3), nigrosporalactone (4), and phomalactone (5), were isolated from the fermentation culture of Nigrospora sp. YB-141, an endophytic fungus isolated from Azadirachta indica A. Juss. The structures of the new compounds were elucidated on the basis of spectroscopic analysis. The antifungal activities of 1-5 towards seven phytopathogenic fungi were tested. Most of the compounds exhibited no or only weak antifungal activities.

Chemical constituents from the stem bark of Trewia nudiflora

Trewia nudiflora L. is the only member of the genus Trewia (Euphorbiaceae), which is mainly distributed in India, Malaysia, and southwest of China. Previous studies have shown that the seed of T. nudiflora is a rich source of maytansinoid tumor inhibitors [1, 2]. Phytochemical studies are mainly focused on the seed and pericarp of the plant; however, there are only few reports on its stem bark [3, 4]. The air-dried powdered stem bark of T. nudiflora (8.8 kg) was extracted with 95% EtOH three times at room temperature. The EtOH extract was concentrated in vacuum to give a residue. The residue was suspended in water and successively treated with EtOAc. The EtOAc extract (32 g) was subjected to chromatography on silica gel eluting with CHCl3–MeOH gradient (1:0–0:1) to give nine fractions (I–IX). Fraction III was repeatedly subjected to column chromatography on RP-18 silica gel with MeOH-H2O (2:3) and Sephadex LH-20 with MeOH to give compound 1 (9 mg). Repeated chromatography of fraction IV on silica gel with petroleum ether–Me2CO gradient (4:1, 7:3, 6:4) and RP-18 silica gel with MeOH–H2O gradient (2:3, 1:1) afforded compounds 2 (6 mg) and 3 (10 mg). Fraction V was submitted to repeated column chromatography on silica gel with CHCl3–MeOH gradient (15:1, 10:1) and RP-18 silica gel with MeOH–H2O gradient (3:7, 2:3) to afford compounds 4 (13 mg), 5 (18 mg), and 6 (10 mg). Fraction VI was chromatographed on silica gel column with CHCl3–MeOH (8:1) to yield compounds 7 (16 mg) and 8 (13 mg). Trewiasine was isolated from the stem bark of T. nudiflora for the first time. Compounds 2–8 were isolated from this plant for the first time. The structures of these compounds were confirmed using a combination of spectral analyses, including NMR and mass spectrometry, and by comparison with reported spectroscopic data in the literature. Trewiasine (1). C37H52ClN3O11, colorless crystals, mp 180−182°C. ESI-MS m/z: 772 [M+Na]+. 1H NMR (500 MHz, CDCl3, δ, ppm, J/Hz): 2.19 (1H, dd, J = 14.5, 3.1, H-2a), 2.56 (1H, dd, J = 14.5, 12.0, H-2b), 4.77 (1H, dd, J = 12.0, 3.1, H-3), 0.78 (3H, s, 4-CH3), 3.02 (1H, d, J = 9.7, H-5), 1.28 (3H, d, J = 6.3, 6-CH3), 4.29 (1H, m, H-7), 3.53 (1H, d, J = 9.0, H-10), 5.74 (1H, dd, J = 15.1, 9.0, H-11), 6.46 (1H, dd, J = 15.1, 11.2, H-12), 6.99 (1H, d, J = 11.2, H-13), 1.54 (3H, s, 14-CH3), 4.87 (1H, s, H-15), 6.55 (1H, d, J = 1.5, H-17), 7.24 (1H, d, J = 1.4, H-21), 3.35 (3H, s, 10-OCH3), 3.37 (3H, s, 15-OCH3), 4.01 (3H, s, 20-OCH3), 3.18 (3H, s, 18-NCH3), 5.39 (1H, m, H-2′), 1.29 (3H, d, J = 6.8, 2′-CH3), 2.89 (3H, s, 2′-NCH3), 2.79 (1H, m, H-4′), 1.13 (3H, d, J = 6.8, 4′-CH3), 1.08 (3H, d, J = 6.5, 4′-CH3), 6.28 (1H, s, 9-NH). 13C NMR (125 MHz, CDCl3, δ, ppm): 32.3 (C-2), 78.1 (C-3), 59.9 (C-4), 67.4 (C-5), 38.8 (C-6), 74.1 (C-7), 36.0 (C-8), 80.7 (C-9), 85.3 (C-10), 129.6 (C-11), 132.5 (C-12), 127.8 (C-13), 142.0 (C-14), 86.6 (C-15), 141.3 (C-16), 120.2 (C-17), 139.2 (C-18), 119.2 (C-19), 156.2 (C-20), 108.7 (C-21), 176.7, 170.8, 168.7, 152.2 (4 × C=O), 56.3, 56.5, 56.7 (3 × OCH3), 14.5, 13.0, 11.9, 9.9 (4 × CH3), 35.2 (18-NCH3), 30.6 (2′-NCH3), 52.4 (C-2′), 30.4 (C-4′), 19.4, 18.8 (2 × 4′-CH3) [1, 2]. Balanophonin (2). C20H20O6, pale yellow oil. EI-MS (70 eV) m/z (%): 356 [M] + (82), 338 (100), 326 (55), 306 (18), 295 (7), 152 (24), 137 (22), 115 (12), 77 (14). 1H NMR (500 MHz, CD3COCD3, δ, ppm, J/Hz): 7.04 (1H, d, J = 1.9, H-2), 6.81 (1H, d, J = 8.1, H-5), 6.88 (1H, dd, J = 8.1, 1.9, H-6), 5.65 (1H, d, J = 6.7, H-7), 3.64 (1H, m, H-8), 3.85 (2H, d, J = 4.9, H-9), 7.29 (1H, d, J = 1.7, H-2′), 7.31 (1H, d, J = 1.7, H-6′), 7.58 (1H, d, J = 15.8, H-7′), 6.66 (1H, dd, J = 15.8, 7.8, H-8′), 9.63 (1H, d, J = 7.8, H-9′), 3.82 (3H, s, 3-OMe), 3.89 (3H, s, 5′-OMe). 13C NMR (125 MHz, CD3COCD3, δ, ppm): 133.7 (C-1), 110.5 (C-2), 148.4 (C-3), 147.5 (C-4), 115.7 (C-5), 119.7 (C-6), 89.4 (C-7), 54.2 (C-8), 64.1 (C-9), 128.9 (C-1′), 119.6 (C-2′), 131.2 (C-3′), 152.4 (C-4′), 145.6 (C-5′), 113.5 (C-6′), 154.1 (C-7′), 127.1 (C-8′), 193.8 (C-9′), 56.2 (3-OMe), 56.4 (5′-OMe) [5].

Starmerella jinningensis sp. nov., a yeast species isolated from flowers of Erianthus rufipilus.

Five yeast strains (Ym24403, Ym24404, Ym24408, Ym24409 and Ym24410(T)) were isolated from different flowers of Erianthus rufipilus (Gramineae), a wild plant growing in the phosphorus-rich region in Yunnan Province, south-western China, and were found to be phenotypically and genetically divergent from currently recognized yeast species. Sequence analysis of the D1/D2 domain of the large subunit rRNA gene revealed that the five strains represented a novel species described as Starmerella jinningensis sp. nov. The type strain is Ym24410(T) (= CBS 11864(T) =CCTCC AY 2011002(T)). Phylogenetic analysis based on the D1/D2 region of the large subunit rRNA gene suggested that S. jinningensis sp. nov. is placed within the Starmerella clade.

Ornithinicoccus halotolerans sp. nov., and emended description of the genus Ornithinicoccus.

A halotolerant actinobacterial strain, designated EGI 80423T, was isolated from a desert soil of Xinjiang, north-west China, and subjected to a polyphasic taxonomic characterization. Strain EGI 80423T grew at pH 7.0-10.0 and with 0-14.0% (w/v) NaCl, optimally at pH 8.0-9.0 and with 2.0-4.0% (w/v) NaCl. Cells of strain EGI 80423T were Gram-stain-positive, non-motile cocci with diameters of 0.6-0.8 μm. The diagnostic diamino acid of the peptidoglycan was ornithine, and the interpeptide bridge was Orn ← Glu. The major fatty acids identified were iso-C17:1ω9c, iso-C15:0 and iso-C17:0. The predominant menaquinone was MK-8(H4), while the polar lipids were diphosphatidylglycerol, phosphatidylglycerol, two unknown phospholipids, two unknown glycolipids, six unknown phosphoglycolipids and five unknown polar lipids. The G+C content of the genomic DNA was 72.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain EGI 80423T clustered with the single member of the genus Ornithinicoccus. Sequence similarity between strain EGI 80423T and Ornithinicoccus hortensis NBRC 16434T. Because the type strain has been provided by NBRC, Japan was 97.7%. The DNA-DNA relatedness value between strain EGI 80423T and O. hortensis NBRC 16434T was 36.84%. Based on morphological, chemotaxonomic and phylogenetic characteristics, and DNA-DNA hybridization data, strain EGI 80423T represents a novel species of the genus Ornithinicoccus, for which the name Ornithinicoccus halotolerans sp. nov. is proposed. The type strain is EGI 80423T (=CGMCC 1.14989T=KCTC 39700T). The description of the genus Ornithinicoccus has also been emended.

Chemical constituents from the root bark of Paeonia delavayi

The genus Paeonia is the only member of the family Paeoniaceae. The plants in this genus are rich in monoterpene glycosides, which have been established as the main biologically active constituents [1–3]. The root bark of Paeonia delavayi Franch., one of the main sources of Chinese traditional medicine “mudanpi”, is an important herb known for its analgesic, sedative, and antiinflammatory properties. It is also used as a remedy for female diseases in traditional oriental medicine [4–6]. Previous studies on this plant led to the isolation of monoterpene glycosides [7, 8]. In continuation of our investigation into the chemical constituents of this plant, we isolated nine compounds 1−9. The root bark of P. delavayi was collected from Lijiang County, Yunnan Province, the People′s Republic of China and was identified by Prof. Zheng-Wei Lu of Kunming Institute of Botany, Chinese Academy of Science. A voucher specimen has been deposited in the Herbarium of Kunming Institute of Botany. The air-dried powdered root bark of P. delavayi (5 kg) was extracted with 95% EtOH three times at room temperature. The EtOH extract was concentrated in vacuum to give a residue. The residue was suspended in water and successively treated with EtOAc. The EtOAc extract (53 g) was subjected to chromatography on eluting with CHCl3–MeOH gradient (1:0−0:1) to give eight fractions (I−VIII). Fraction I was repeatedly subjected to silica gel column chromatography with petroleum ether−EtOAc (9:1) to give compounds 7 (11 mg) and 9 (325 mg). Fraction II was subjected to silica gel column chromatography with petroleum ether−acetone (9:1) to give compounds 1 (27 mg) and 3 (18 mg). Fraction III was subjected to silica gel column chromatography with chloroform−acetone gradient (9:1, 4:1) to give compounds 2 (25 mg) and 6 (21 mg). Repeated chromatography of fraction V on silica gel with CHCl3−MeOH gradient (95:5, 9:1, 85:15) and RP-18 silica gel with MeOH−H2O gradient (3:7, 4:6, 1:1) afforded compounds 4 (12 mg) and 5 (35 mg). Fraction VI was submitted to silica gel column chromatography with CHCl3–MeOH (4:1) to afford compound 8 (68 mg). The compounds identified as oleanolic acid (1) [9, 10], 3β,23-dihydroxy-30-norolean-12, 20(29)-dien-28-oic acid (2) [9, 10], akebonic acid (3) [11], arjunglucoside II (4) [12], 3-O-β-D-glucopyranoside β-sytosterine (5) [13, 14], syringic acid (6) [15], p-hydroxybenzoic acid (7) [16], gallic acid (8) [17], and benzoic acid (9) [18]. Oleanolic Acid (1). C30H48O3, mp 202–204°C, colorless crystals (acetone). IR (KBr, ν, cm–1): 3440, 2938, 2870, 1695, 1461, 1385, 1363, 1271, 1183, 1030, 996). 3β,23-Dihydroxy-30-norolean-12,20(29)-dien-28-oic Acid (2). C29H44O4, mp 241–243°C, colorless crystals (acetone). IR (KBr, ν, cm–1): 3438, 2940, 1688, 1465, 1384, 1298, 1215, 1105, 885. Akebonic Acid (3). C29H44O3, mp 152–154°C, colorless crystals (acetone). IR (KBr, ν, cm–1): 3424, 2935, 1691, 1653, 1463, 1384, 1297, 1212, 1102, 996, 886. Arjunglucoside II (4). C36H58O10, white powder. UV (MeOH, λmax, nm): 207.0 (log ε 3.71). IR (KBr, ν, cm –1): 3414, 2941, 1731, 1556, 1391, 1259, 1177, 1072, 893, 472. The structures of these compounds were confirmed using a combination of spectral analyses, including NMR and mass spectrometry and by comparison with reported spectroscopic data in the literature. Compounds 1−8 were isolated from P. delavayi Franch. for the first time.