Pyrrole alkaloids from Bolbostemma paniculatum

Three pyrrole alkaloids were isolated from Bolbostemma paniculatum. Their structures were elucidated as 4-(2-formyl-5-methoxymethylpyrrol-1-yl)butyric acid methyl ester (1), 2-(2-formyl-5-methoxymethylpyrrol-1-yl)-3-phenylpropionic acid methyl ester (2) and alpha-methyl pyrrole ketone (3) by spectroscopic techniques. Among them, 1 and 2 are new compounds.     

Antioxidant caffeic acid derivatives from leaves of<Emphasis Type="Italic">parthenocissus tricuspidata</Emphasis>

Five caffeic acid derivatives; methyl ester of caffeoylglycolic acid (1), dimethyl ester of caffeoyltartaric acid (2), dimethyl ester of caffeoyltartronic acid (3), monomethyl ester of caffeoyltartronic acid (4), methyl ester of caffeic acid (5), and some other secondary metabolites including; quercetin, quercetin 3-O-beta-D-glucuronide methyl ester, kaempferol, 3,5,7,4'-O-tetramethylkaempferol, beta-sitosterol glucoside, 2alpha-hydroxyursolic acid and 2,24-dihydroxyursolic acid, have been isolated and characterized. All the isolated compounds were characterized with the help of NMR spectroscopy and mass spectrometry. Structure of compound 3 was also confirmed by a single X-ray crystallographic technique. Isolates were evaluated for antioxidant activities and most of the tested compounds were found to be potent in DPPH free radical scavenging (IC50 = 4.56-14.17 microg/mL) and superoxide anion scavenging (IC50 = 0.58-7.39 microg/mL) assays.     

Pyrrole alkaloids from Bolbostemma Paniculatum

Three pyrrole alkaloids were isolated from Bolbostemma paniculatum. Their structures were elucidated as 4-(2-formyl-5-methoxymethylpyrrol-1-yl)butyric acid methyl ester (1), 2-(2-formyl-5-methoxymethylpyrrol-1-yl)-3-phenylpropionic acid methyl ester (2) and α-methyl pyrrole ketone (3) by spectroscopic techniques. Among them, 1 and 2 are new compounds.     

New dianthramide and cinnamic ester glucosides from the roots of Aconitum carmichaelii

Four new compounds N-salicyl-3-hydroxyanthranilic acid methyl ester (1), N-(2′-dehydroxysalicyl)-3-hydroxyanthranilic acid methyl ester (2), methyl-4-β-D-allopyranosyl-ferulate (3), and methyl-4-β-D-gulopyranosyl-cinnamate (4), along with six known compounds (5–10), were isolated from the roots of Aconitum carmichelii Debx. Their structures were elucidated on the basis of spectral data analysis, including 1D, 2D-NMR, and HR-ESI-MS. Compounds 1 and 2 showed the inhibition of nitric oxide (NO) production with IC₅₀ values of 9.13 and 19.94 μM, respectively.     

Protoberberine alkaloids and their reversal activity of P-gp expressed multidrug resistance (MDR) from the rhizome ofCoptis japonica Makino

Six protoberberine alkaloids were isolated from the chloroform layer of the rhizome of Coptis japonica Makino (Ranunculaceae). The structures of the isolated compounds were determined to be 6-([1,3]dioxolo[4,5-g]isoquinoline-5-carbonyl)-2,3-dimethoxy-benzoic acid methyl ester (1), oxyberberine (2), 8-oxo-epiberberine (3), 8-oxocoptisine (4), berberine (5) and palmatine (6) by physicochemical and spectroscopic methods. The compound 3 (8-oxo-epiberberine) was first isolated from natural sources. The compounds were tested for cytotoxicity against five tumor cell lines in vitro by SRB method, and also tested for the MDR reversal activities. Compound 4 was of significant P-gp MDR inhibition activity with ED50 value 0.018 microg/mL in MES-SA/DX5 cell and 0.0005 microg/mL in HCT15 cell, respectively.     

New Aconitine-Type C<Subscript>19</Subscript>-Diterpenoid Alkaloids from<Emphasis Type="Italic">Aconitum hemsleyanium</Emphasis> var.<Emphasis Type="Italic">circinacum</Emphasis>

Two new aconitine-type C19-diterpenoid alkaloids, hemsleyanines C (1) and D (2), were isolated from the roots of Aconitum hemsleyanium var. circinacum, their structures were determined by the chemical evidence and spectral analyses.     

Three new diterpene alkaloids from the roots of Aconitum nagarum var. lasiandrum

Three new diterpene alkaloids, 16,17-dihydro-12 beta,16 beta-epoxynapelline (1), N-deethyl- N-methyl-12-epi-napelline (2) and 11- epi-16 alpha,17-dihydroxylepenine (3), along with twenty-six known alkaloids (4 - 29) were isolated from the roots of Aconitum nagarum var. lasiandrum. The chemical structures of the new compounds were established by HR-MS as well as 1D- and 2D-NMR spectroscopic analysis. The absolute stereochemistry of 1 was confirmed by X-ray crystallography.     

Two new diterpenoid alkaloids from Aconitum cochleare

Two new diterpenoid alkaloids, cochleareine (1) and acoleareine (2) together with the known alkaloids 14-acetyltalatisamine (3) and talatisamine (4) have been isolated from the aerial parts of Aconitum cochleare Woroschin growing wild in Eastern Turkey (Van).     

异叶三宝木枝条的化学成分研究

目的 研究异叶三宝木 (Trigonostemon heterophyllus Merr.)枝条乙醇提取物的化学成分。方法 采用硅胶柱色谱、Sephadex LH-20凝胶柱色谱和 RP-18柱色谱进行分离纯化, 并根据波谱数据进行结构鉴定。 结果 从异叶三宝木中分离得到8个化合物,经波谱分析鉴定其结构为原儿茶酸甲酯 (1)、3-羟基-4-甲氧基苯甲酸甲酯 (2)、反式对羟基桂皮酸甲酯 (3)、4-羟基-3-甲氧基苯甲酸 (4)、jacareubin (5)、(+)-lyoniresinol (6)、表百麦根苷 (7)和 β-谷甾醇 (8)。结论 以上化合物均为首次从该属植物中分离得到。滤纸片琼脂扩散法表明化合物 5 对于金黄色葡萄球菌 (SA)和耐甲氧西林金黄色葡萄球菌 (MRSA)有抑制作用。     

Antitussive indole alkaloids from Kopsia hainanensis

Three new indole alkaloids, named kopsihainins A-C (1-3), and two known compounds, kopsinine (4) and methyl demethoxycarbonylchanofruticosinate (5), were isolated from the stems of Kopsia hainanensis. Their structures were determined using extensive spectroscopic methods. The two main constituents 4 and 5 exhibited significant antitussive activity in a citric acid induced guinea pig cough model. The antitussive effect of 4 was demonstrated to interact with the δ-opioid receptor. This is the first report of antitussive effects of aspidofractinine type and chanofruticosinate type alkaloids.     

Antiplasmodial activity of Cryptolepis sanguinolenta alkaloids from leaves and roots

The roots of Cryptolepis sanguinolenta have been investigated for their chemical composition since 1931 but so far no studies on the leaves have been reported although they are used in traditional medicine in Guinea-Bissau. Two new alkaloids identified as cryptolepinoic acid (1) and methyl cryptolepinoate (2) and the known alkaloids cryptolepine (4), hydroxycryptolepine (5/5a) and quindoline (6), were isolated from the ethanolic and chlorophormic leaf extracts. Aqueous and ethanolic extracts of the leaves and roots and seven alkaloids isolated from those extracts were tested in vitro against Plasmodium falciparum K1 (multidrug-resistant strain) and T996 (chloroquine-sensitive clone). All the extracts were shown to give 90% inhibition of P. falciparum K1 growth at concentrations < 23 micrograms/ml. Cryptolepine (4) was the most active alkaloid tested with IC50 values (0.23 microM to K1; 0.059 microM to T996) comparable with chloroquine (0.26 microM to K1; 0.019 microM to T996). The indolobenzazepine alkaloid cryptoheptine (7) was the second most active with IC50 values of 0.8 microM (K1) and 1.2 microM (T996). Cryptolepinoic acid (1) showed no significant activity while its ethyl ester derivative 3 was active against P. falciparum K1 (IC50 = 3.7 microM). All the indoloquinoline alkaloids showed cross-resistance with chloroquine but not the indolobenzazepine alkaloid 7. It was noticed that alkaloids with weakly basic characteristics were active whereas other structurally related alkaloids with different acid-base profiles were inactive. These observations are in agreement with the antimalarial mechanism of action for quinolines.     

Norditerpenoid alkaloids and other components from the processed tubers ofaconitum carmichaeli

A new norditerpenoid and a known alkaloid were isolated from the alkaloidal fraction of the processed tubers of Aconitum carmichaeli. The structure of the new norditerpenoid alkaloid was elucidated as lipoforesaconitine (1) on the basis of spectroscopic analysis. The known norditerpenoid alkaloid was characterized as lipoyunanaconitine (2). In addition, a new flavonoid, 6"-O-acetylliquiritin (7), along with a known ceramide, (2S,3S,4R,8E)-2-[(2'R)-2'-hydroxylignoceroylamino]-8(E)-octadecene-1,3,4-triol (3), as well as a known steroid saponin, gracillin (8), and three known flavonoids, liquiritigenin (4), isoliquiritigenin (5), and liquiritin (6), were also isolated and characterized. All known compounds were isolated from this plant for the first time. The structures of the isolates were established by spectroscopic and chemical methods.     

Polygosumic acid,a new cadinane sesquiterpene from <Emphasis Type="Italic">Polygonum viscosum</Emphasis>, inhibits the growth of drug-resistant <Emphasis Type="Italic">Escherichia coli</Emphasis> and <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> (MRSA) in vitro

Three new sesquiterpenes, 6-hydroxy-7-(1-methylethyl)-3,3a,6,7,8,8a-hexahydroazulene-1,4-dicarboxylic acid methyl ester (1, named viscozulenic acid methyl ester), 7-(1-methylethyl)-3,3a,6,7,8,8a-hexahydroazulene-1,4-dicarboxylic acid 1-methyl ester (2, named viscoazucinic acid) and 3-oxo-1-epi-sclerosporin (3, named polygosumic acid), have been isolated from the chloroform extract of the aerial parts of Polygonum viscosum by reversed-phase preparative high performance liquid chromatography (HPLC). The structures of these compounds were established conclusively by ultraviolet (UV), mass spectrometry (MS) and a series of 1D and 2D nuclear magnetic resonance (NMR) analyses. The anti-bacterial properties of 1–3 against 12 pathogenic bacterial strains have also been assessed by the rapid and robust microtitre-plate-based serial dilution method incorporating resazurin as an indicator of cell growth. Polygosumic acid was the most active among the sesquiterpenes and inhibited the growth of penicillin-resistant Escherichia coli (minimum inhibitory concentration, MIC=0.05 mg/ml) and methicillin-resistant Staphylococcus aureus (MRSA) (MIC=0.10 mg/ml).     

Studies on structural elucidation of Aconitum diterpenoid alkaloid by LC-APCI-MS and effects of Aconitum diterpenoid alkaloid on cutaneous blood flow

The chemical constituents of Aconitum yesoense var. macroyesoense and Aconitum japonicum were examined using high-resolution spectral analysis. Twelve novel alkaloids were isolated from A. yesoense var. macroyesoense together with 20 known alkaloids. Eight novel alkaloids were isolated from A. japonicum together with 15 known alkaloids. An HPLC-atmospheric pressure chemical ionization-mass spectrometry (HPLC-APCI-MS) method was useful for the simultaneous determination of 21 Aconitum alkaloids found in A. yesoense var. macroyesoense and A. japonicum. These compounds were fairly stable under the conditions used, and the protonated molecules or fragment ions characteristic of the molecule appeared as base peaks in the mass spectra and were used for selected ion monitoring. HPLC-APCI-MS is a very promising approach for structural investigations of positional isomers and stereoisomers. This method was applied successfully to stereoisomeric Aconitum alkaloids differing in configuration at C-1, -6, or -12. Comparison of the APCI spectra showed that the abundance of fragment ions was significantly higher for the C-1, -6, or -12 beta-form alkaloid than for C-1, -6, or -12 alpha-form alkaloid. The main alkaloid constituents in the root of A. yesoense var. macroyesoense, Aconitum alkaloids of the C20-diterpenoid type, kobusine and pseudokobusine, and their acyl derivatives were examined for their peripheral vasoactivities by measuring laser-flowmetrically the cutaneous blood flow in the hind foot of mice after intravenous administration. It is thought that the hydroxyl groups of alkaloids, especially a free OH group of pseudokobusine at C-6, were important for action on the peripheral vasculature leading to dilatation, and the results indicated that esterification of the hydroxyl group at C-15 with either anisoate, veratroate, or p-nitroben-zoate may contribute to enhancement of the activity of the parent alkaloids.     

Norditerpenoid alkaloids from the roots of Aconitum leave Royle

From the roots of Aconitum leave Royle growing wild in Northern Pakistan, Swat district, three new alkaloids, 8-methyllycaconitine (1), 14-demethyllycaconitine (2), N-deethyllycaconitine-N-aldehyde (3) have been isolated along with four known compounds, lappaconitine (4), lycaconitine (5), lapaconidine (6) and lycoctonine (7).     

Sabian, a novel flavonoid from Sabiayunnanensis

A novel flavonoid, [2-(3,4-dihydroxy-phenyl)-3,5,7-trihydroxy-4-oxo-4H-chromen-8-yl]-[8-hydroxy-7-(E-4-hydroxy-3-methyl-but-2-enyl)-2,2-dimethyl-chroman-5-yl]-acetic acid methyl ester (10), trivially named sabian, along with 11 known compounds, have been isolated from the stems and leaves of Sabia yunnanensis. Their structures were established on the basis of spectral analysis.     

Triterpenoids from Peganum nigellastrum

Two triterpenoids were isolated from the roots of Peganum nigellastrum Bunge. Their structures were elucidated as 3alpha-acetoxy-27-trans-caffeoyloxyolean-12-en-28-oic acid methyl ester (1) and 3-oxotirucalla-7, 24-dien-21-oic acid (2) on the basis of spectroscopic evidence. 1 is a new triterpene ester and 2 is a known compound isolated for the first time from genus Peganum.     

群海绵Agelas sp.的化学成分研究

目的 研究海绵Agelas sp.的化学成分。方法 运用乙醇提取、硅胶、Sephadex-LH₂₀色谱柱、HPLC等多种方法进行分离和纯化,根据理化性质和波谱数据进行结构鉴定。结果 分离得到9个化合物,经结构鉴定分别为4,5-二溴吡咯-2-甲酰胺（1）、4,5-二溴吡咯-2-甲酸（2）、4,5-二溴吡咯-2-甲酸甲酯（3）、N-（4,5-二溴-2-吡咯甲酰基）甘氨酸甲酯（4）、1-（4,5-二溴-2-吡咯甲酰胺基）丙酸甲酯（5）、1-（4,5-二溴-2-吡咯甲酰胺基）丙酸乙酯（6）、异吲哚-1,3-二酮（7）、2（3H）-苯并噻唑酮（8）和manzacidin C（9）。结论 化合物4~9为首次从该属海绵中分离得到,其中化合物4~6为新天然产物。     

Norditerpenoid alkaloids from Aconitum manshuricum

A new norditerpenoid alkaloid, manshuritine (1) has been isolated from Aconitum manshuricum, together with seven known alkaloids; beiwudine (2), beiwutine (3), 16-epi-pyromesaconitine (4), mesaconitine (5), aconitine (6), hypaconitine (7) and 14-benzoylmesaconine (8). The structure of the new compound was elucidated on the basis of spectral data and chemical correlations.     

Tropane alkaloids from <Emphasis Type="Italic">Erythroxylum emarginatum</Emphasis>

A tropane alkaloid, anhydroecgonine methyl ester N-oxide (2), was isolated for the first time as a naturally occurring compound, with anhydroecgonine methyl ester (1) from the bark of Erythroxylum emarginatum. Compound 1 was also isolated from the twigs. Their structures were elucidated mainly by spectroscopic methods.