Quassinoids from the twigs and thorns of Castela polyandra

The structures of six new C20 quassinoids and one new C19 quassinoid, all isolated from the twigs and thorns of Castela polyandra, were established by a combination of spectroscopic and single-crystal X-ray analysis. Five known quassinoids and one known sterol were also identified.     

Anti-liver cancer constituents from the thorns of Gleditsia sinensis

Four new long-chain esters of trans-ferulic acid (1–4) were isolated from the thorns of Gleditsia sinensis, together with eight known compounds (5–13). The structure elucidations were achieved by in-depth spectroscopic examination, mainly including multiple 1D- and 2D-NMR and HRESIMS experiments and analyses. Cytotoxic activities of these compounds were evaluated against human liver cancer SK-hep-1 cell line by the MTT in vitro assay. Among them, compound 13 exhibited potent cytotoxic activity with IC₅₀ value of 38.18 μM, and compounds 7 and 8 showed moderate cytotoxic activities with IC₅₀ values of 58.11 and 54.61 μM, respectively.     

New phenolic constituents from Balanophora polyandra with radical-scavenging activity

The 80% acetone extract of Balanophora polyandra Griff. (Balanophoraceae) was found to exhibit high radical-scavenging activity (SC(50)=14.48 mug/ml) towards 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. Further chemical investigation led the isolation of two new hydrolysable tannins, balapolyphorins A (1) and B (2), together with 20 known phenolic compounds (3-22). Their structures were established by detailed spectroscopic analysis, and the radical-scavenging properties of all isolated compounds were determined by DPPH assay.     

Diprenylated chalcones and other constituents from the twigs of Dorstenia barteri var. subtriangularis

The twigs of Dorstenia barteri var. subtriangularis yielded three diprenylated chalcones: (-)-3-(3,3-dimethylallyl)-5'-(2-hydroxy-3-methylbut-3-enyl)-4,2',4'-trihydroxychalcone, (+)-3-(3,3-dimethylallyl)-4',5'-[2'-(1-hydroxy-1-methylethyl)-dihydrofurano]-4,2'-dihydroxychalcone and 3,4-(6",6"-dimethyldihydropyrano)-4',5'-[2',-(1-hydroxy-1-methylethyl)-dihydrofurano]-2'-hydroxychalcone for which the names bartericins A, B and C, respectively, are proposed. Stipulin, beta-sitosterol and its 3-beta-D-glucopyranosyl derivative were also isolated. The structures of these secondary metabolites were determined on the basis of spectroscopic analysis, especially, NMR spectra in conjunction with 2D experiments, COSY, HMQC and HMBC. The structural relationship of bartericins B and C was further established by the chemical cyclization of one to the other.     

毛果巴豆枝叶的化学成分研究

为研究毛果巴豆枝叶中的化学成分,该文采用硅胶、Sephadex LH-20柱色谱以及HPLC等多种色谱相结合的方法,对毛果巴豆枝叶95%乙醇提取物的乙酸乙酯萃取部位进行分离,从中得到8个化合物,通过波谱数据分析并结合文献比对,将其鉴定为2β-hydroxyteucvidin acetate(1),2β-hydroxyteucvidin(2),crotoeurin B(3),山奈酚-3-O-(6″-O-顺式对香豆酰基)-β-D-吡喃葡萄糖苷(4),山奈酚-3-O-(6″-O-反式对香豆酰基)-β-D-吡喃葡萄糖苷(5),栗苷A(6),cerevisterol(7),尿嘧啶(8)。化合物2-7均为首次从该植物中分离得到。     

Phytochemical constituents of leaves and twigs of Elaeagnus umbellata

A phytochemical study of the leaves and twigs of Elaeagnus umbellata Thunb. has led to the isolation and identification of 12 compounds, including two flavonoid coumaroyl glycosides (1 and 2), two simple phenolic compounds (3 and 4), one coniferyl alcohol derivative (5), one monoterpene (6), two pairs of enantiomeric neolignans (7a/7b and 8a/8b), and a pair of enantiomeric sesquineolignans (9a/9b). The structures of these compounds were elucidated through the analysis of their MS, ECD, and 1D/2D NMR spectra as well as comparison with previously reported data. This is the first time that 1 and 2 have been isolated from this species, and the first time that 5, 6, 7a, 7b, 8a, 8b, 9a, and 9b have been identified in the Elaeagnaceae family.     

Rotenoid derivatives and other constituents of the twigs of Millettia duchesnei

Three prenylated rotenoids, elliptol, 12-deoxo-12alpha-methoxyelliptone and 6-methoxy-6a,12a-dehydrodeguelin were isolated from the twigs of Millettia duchesnei, together with the known compounds, 6a,12a-dehydrodeguelin, 6-hydroxy-6a,12a-dehydrodeguelin, 6-oxo-6a,12a-dehydrodeguelin, elliptone, 12a-hydroxyelliptone and eriodictyol. Their structures were elucidated on the basis of spectral data and comparison with information reported in the literature and with authentic specimens for some known compounds. The full NMR data of 6-oxo-6a,12a-dehydrodeguelin and 6-hydroxy-6a,12a-dehydrodeguelin are reported here for the first time.     

多蕊商陆的化学成分

从多蕊商陆（Phytolacca polyandra)根的乙醇提取物中分到一个新的环二肽,两个已知的环二肽的混合物以及两个甾体化合物。根据化学和光谱数据,它们的化学结构分别确定为：环（脯氨酸－酪氨酸）（1）,环（丙氨酸－亮氨酸）（2）,环（丙氨酸－异亮氨酸）（3）,α－菠甾醇（4）和α－菠甾醇吡喃葡萄糖苷（5）。在商陆科植物中,环肽成分是首次被发现。     

Prenylated flavonoids, monoterpenoid furanocoumarins and other constituents from the twigs of Dorstenia elliptica (Moraceae)

A monoprenylated flavan and two monoterpenoid substituted furanocoumarins were isolated from the twigs of Dorstenia elliptica along with 3-(3,3-dimethylallyl)-4,2',4'-trihydroxylchalcone, psoralen, bergapten, O-[3-(2,2-dimethyl-3-oxo-2H-furan-5-yl)butyl]bergaptol, beta-sitosterol and its beta-D-glucopyranoside. The structure of the flavan was determined as 6(1,1-dimethylallyl)-7,4'-dihydroxylflavan and the monoterpenoid substituted furanocoumarins were assigned as O-[3-(2,2-dimethyl-3-oxo-2H-furan-5-yl)-3-hydroxybutyl]-bergaptol and O-[2-(5-hydroxy-2,6,6-trimethyl-3-oxo-2H-pyran-2-yl)ethyl]bergaptol, respectively, using spectroscopic analysis, especially, 2D NMR spectra.     

Xanthine oxidase inhibitory activity of constituents of Cinnamomum cassia twigs

A methanol extract of the twigs of Cinnamomum cassia was found to inhibit xanthine oxidase. Purification of the methanol extract afforded three new phenolic glycosides, cinnacasolide A-C (11-13), together with 10 known compounds (1-10). The structures of the three new compounds were determined by interpretation of spectroscopic data. Cinnamaldehyde derivatives 1-5 and 7 were significant inhibitors of xanthine oxidase, with IC(50) values ranging from 7.8 to 36.3 μg/mL. The results indicate that the acyl group of these cinnamaldehyde derivatives plays an important role in the inhibition of xanthine oxidase.     

Anti-inflammation activities of essential oil and its constituents from indigenous cinnamon (Cinnamomum osmophloeum) twigs

In this study, chemical compositions of hydrodistilled essential oil and anti-inflammatory activities from the twigs of Cinnamomum osmophloeum Kaneh. were investigated for the first time. The chemical constituents of the twig essential oil were further analyzed by GC-MS and they were found to be L-bornyl acetate (15.89%), caryophyllene oxide (12.98%), gamma-eudesmol (8.03%), beta-caryophyllene (6.60%), T-cadinol (5.49%), delta-cadinene (4.79%), trans-beta-elemenone (4.25%), cadalene (4.19%), and trans-cinnamaldehyde (4.07%). The effects of essential oil on nitric oxide (NO) and prostaglandin E2 (PGE2) production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages were also examined. Results of nitric oxide tests indicated that twig essential oil and its major constituents such as trans-cinnamaldehyde, caryophyllene oxide, L-borneol, L-bornyl acetate, eugenol, beta-caryophyllene, E-nerolidol, and cinnamyl acetate have excellent activities. These findings demonstrated that essential oil of C. osmophloeum twigs have excellent anti-inflammatory activities and thus have great potential to be used as a source for natural health products.     

Dinklagins A,B and C: three prenylated flavonoids and other constituents from the twigs of Dorstenia dinklagei

The dichloromethane extract of the aerial parts of Artabotrys hexapetalus afforded three beta-methoxy-gamma-methylene-alpha,beta-unsaturated-gamma-butyrolactones, which are proposed to be derived from a C(18) unsaturated fatty acid by a biosynthetic route similar to that proposed for the Annonaceous acetogenins. The structure of the unique beta-methoxy-gamma-methylene-substituted, alpha,beta-unsaturated-gamma-butyrolactone ring of artapetalins A-C (1-3) was determined by 2D-NMR spectroscopic analyses. Two unusual simple butyrolactones, (+)-tulipalin B and (2R,3R)- 3-hydroxy-2-methylbutyrolactone were also isolated from this species.     

Prenylated chalcones, flavone and other constituents of the twigs of Dorstenia angusticornis and Dorstenia barteri var. subtriangularis

The twigs of Dorstenia angusticornis and Dorstenia barteri var. subtriangularis yielded 16 compounds. Two novel diprenylated chalcones: 3,5'-di-(2-hydroxy-3-methylbut-3-enyl)-4,2',4'-trihydroxychalcone, 3, 4-(2,2-dimethylpyrano)-3'-(2-hydroxy-3-methylbut-3-enyl)-2',4'-dihydroxychalcone and the known stipulin were isolated from both species. 3-(2-Hydroxy-3-methylbut-3-enyl)-5'-(3,3-dimethylallyl)-4,2',4'-trihydroxychalcone and the known compounds: 4-hydroxylonchocarpin, kanzonol B, bartericins A, B, C and 3'-(2-hydroxy -3-methylbut-3-enyl)-4,2',4'-trihydroxychalcone were isolated from D. barteri while the known compounds: gancaonin Q, paratocarpins C, F, and lupeol were obtained from Dorstenia angusticornis. beta-Sitosterol and its beta-d-glucopyranoside were isolated from both species. Structures of these secondary metabolites were established using spectroscopic analysis, especially, NMR spectra in conjunction with 2D experiments, COSY, HMQC and HMBC.     

Antimicrobial activity of Araucaria cunninghamii Sweet and the chemical constituents of its twigs and leaves

The present study was aimed at the identification of antimicrobial components from Araucaria cunninghamii with an activity-guided purification process. Eight compounds were obtained from the most active n-BuOH fraction and identified as the new compound 4-n-butoxyl-phenylpropanetriol (1), together with seven known compounds (2–8). These compounds were tested for antimicrobial activities against five bacteria and four plant pathogenic fungi. Within the series of compounds tested, compound 2 was the most active, particularly displaying moderate antibacterial activities against Erwinia carotovora and Bacillus subtilis with MICs 7.8 and 15.5 μg/ml. Moreover, this compound exhibited inhibitory activities against four plant pathogenic fungi: Helminthosporium sativum, Rhizoctonia solani, Fusarium oxysporum f. sp. Niveum and Fusarium oxysporum f. sp. Cubense, with EC₅₀ values of 42.3, 90.0, 62.7 and 100.2 μg/ml. To our knowledge, this is the first report that the n-BuOH fraction and compound 2 from A. cunninghamii showed inhibitory activity against plant pathogenic fungi.     

Flavonoids from the leaves and twigs of Knema elegans

Knema elegans, a tropical evergreen plant, belongs to Myristicaceae family. Phytochemical investigation on the leaves and twigs of K. elegans led to the isolation and identification of two new flavonoids knemavones A and B (1 and 2), along with fifteen known analogues (3–17). These compounds belong to four subtypes of flavonoids, including chalcones, flavanes, flavones, and isoflavones. The structures of 1 and 2 were elucidated by means of spectroscopic techniques, including HRESIMS, 1D, and 2D NMR experiments. Compounds 3–17 are isolated from the title plant for the first time. Moreover, the new chalcones 1 and 2 could serve as chemotaxonomic markers of K. elegans.     

Pyranocoumarins from the twigs of Mammea siamensis

Four unusual pyranocoumarins (1-4) have been isolated from the dried twigs of M. siamensis. The structures were determined by spectroscopic data, especially 1D and 2D NMR experiments.     

A bichalcone from the twigs of Rhus pyroides

The twigs of Rhus pyroides yielded a novel bichalcone 2',4",2"'-trihydroxy-4',4"'-dimethoxy-4-O-5"'-bichalcone. It was identified on the basis of spectroscopic data including 1D and 2D NMR spectroscopy. The name rhuschalcone-1 is proposed.     

Cytotoxic triterpenes from the twigs of Celtis philippinensis

Two triterpene esters, 3beta-trans-sinapoyloxylup-20(29)-en-28-ol (1) and 3beta-trans-feruloyloxy-16 beta-hydroxylup-20(29)-ene (2), were isolated as cytotoxic constituents from the chloroform-soluble extract of the twigs of Celtis philippinensis, along with five known triterpenes, 3beta-O-(E)-feruloylbetulin (3), 3beta-O-(E)-coumaroylbetulin (4), betulin (5), 20-epibryonolic acid (6), and ursolic acid (7). The structures of 1 and 2 were assigned from their 1D and 2D NMR spectroscopic data. All isolates were evaluated for cytotoxicity against several human cancer cell lines.