Bioactive 5alpha-pregnane-type steroidal alkaloids from Sarcococca hookeriana

The bioassay-guided phytochemical investigation of Sarcococca hookeriana with respect to cholinesterase inhibitory properties has yielded two new 5alpha-pregnane-type steroidal alkaloids, hookerianamides J (1) and K (2), along with eight known compounds (3-10). The structures of 1 and 2 were elucidated by spectroscopic methods. These compounds displayed good to moderate activities in vitro against the enzymes acetylcholinesterase (IC 50 8.1-48.5 microM) and butyrylcholinesterase (IC 50 0.4-4.0 microM). Compounds 1-10 were also tested in vitro for their leishmanicidal activity against Leishmania major and for their antibacterial activities against Bacillus subtilis, Micrococcus luteus, Streptococcus faecalis, and Pseudomonas pallida.     

New cytotoxic steroidal alkaloids from the Philippine sponge Corticium niger

Four new steroidal alkaloids, plakinamine I-K (1-3) and dihydroplakinamine K (4), were isolated from the marine sponge Corticium niger. The structures of these compounds were elucidated by interpretation of spectroscopic data. Compounds 1-4 exhibit significant in vitro cytotoxicity.     

Cytotoxic steroidal alkaloids from Kibatalia laurifolia

Four new steroids, 3-epi-gitingensine (1), N-acetylgitingensine (6), kibalaurifoline (7) and kibalaurifenone (8), along with the known paravallarine (2), 7α-hydroxyparavallarine (3), gitingensine (4), and N-methylgitingensine (5) were isolated from the leaves of Kibatalia laurifolia. Their structures were determined primarily from mass spectrometry and 2D NMR analyses. On the basis of the known absolute configurations of 2 and 4, the absolute configurations of the new compounds were proposed. Due to the structural relationships of compounds 1-8, a biosynthetic pathway was suggested. Compound 2 was cytotoxic to KB cells (IC50 12.8 μM), followed by 1 with IC50 21.2 μM.     

New steroidal alkaloids from an undescribed sponge of the genus Corticium.

Two new steroidal alkaloids, along with a previously reported one of the plakinamine class, were isolated from the sponge Corticium sp. collected from Guam. The structures of the new compounds were determined by combined spectroscopic methods. These compounds exhibited moderate cytotoxicity and antifungal activity as well as DNA- and RNA-cleaving activities.     

Antiophidic solanidane steroidal alkaloids from Solanum campaniforme

Three new solanidane alkaloids bearing a 22,23-epoxy ring (1-3) and four known compounds were isolated from leaves of Solanum campaniforme. The structures were determined using spectroscopic techniques, including 1D and 2D NMR, and HRESIMS experiments. The antiophidic activity of the alkaloids was tested against Bothrops pauloensis venom. Compounds 1-3 completely inhibited myotoxicity without inhibiting phospholipase A2 activity of the venom, while hemorrhage and skin necrosis were significantly reduced in the presence of alkaloids 1 and 2.     

Steroidal alkaloids from the leaves of Sarcococca coriacea of Nepalese origin.

Two new steroidal alkaloids, (-)-vaganine D (1) [(20S)-20-(N,N-dimethylamino)-3 beta-(senecioylamino)-5 alpha-pregn-16-en-4 beta-yl acetate], and (+)-nepapakistamine A (2) [(20S)-20-(N-methylamino)-3 beta-(tigloylamino)-5 alpha-pregn-16-en-2 beta,4 beta-diacetate], were isolated from the leaves of Sarcococca coriacea. Their structures were elucidated on the basis of their spectral properties. Compounds 1 and 2 were found to be cholinesterase inhibitors.     

Minor steroidal alkaloids from the marine sponge Corticium sp

Four new steroidal alkaloids, plakinamine G (1), plakinamine H (2), 4alpha-hydroxydemethylplakinamine B (3), and tetrahydroplakinamine A (4), along with three known compounds, were isolated from the marine sponge Corticium sp. The structures of these metabolites were elucidated largely by 1D and 2D NMR methods and accurate mass measurements (HR-EIMS). Compounds 1, 2, and 4 show significant in vitro cytotoxicity.     

伊犁贝母中2个新的甾体生物碱

目的研究伊犁贝母Fritillaria pallidiflora鳞茎的化学成分。方法采用硅胶柱色谱、制备薄层色谱等色谱方法进行分离纯化,应用质谱、核磁等波谱技术鉴定化合物的结构。结果从伊犁贝母鳞茎80%乙醇水溶液提取物的环己烷部位分离得到4个化合物,分别鉴定为伊贝新(1)、伊贝嗪(2)、2′-甲氧基邪蒿内酯(3)、1-O-β-D-葡萄糖基-(2S,3S,4R,8Z)-2-[(2′R)-(2′-羟基二十二碳酰)氨基]-1,3,4-十八碳三醇-8-烯(4)。结论化合物1、2为新的甾体生物碱。     

反相高效液相色谱法同时分析龙葵中3种甾体生物碱

目的:利用反相高效液相色谱法快速测定龙葵中3种甾体生物碱的含量.方法:采用Agilent Zorbax SB-C1s(4.6mm×150 mm,5μm)色谱柱,以乙腈-1%磷酸为流动相,流速1.0 mL·min-1,进样量20μL,柱温30℃,205 nm条件下检测,以梯度洗脱方式在30 min内分离了澳洲茄碱、澳洲茄边碱和khasianine 3种生物碱.结果:澳洲茄碱含量测定的线性范围为0.860～10.320μg(r=0.999 7);澳洲茄边碱含量测定的线性范围为0.726～8.710μg(r=0.999 7);khasianine含量测定的线性范围为0.696～8.352μg(r=0.9998).方法的平均回收率分别为100.18%,99.08%,99.88%.结论:方法简便快速、准确度高,可用于龙葵药材的质量评价.     

New alkaloids from Pandanus amaryllifolius

Three new alkaloids, the two pyrrolidine type alkaloids (1 and 2) and 6E-pandanamine (3), together with five known alkaloids (4-8), were isolated from the leaves of Pandanus amaryllifolius collected in West Java, Indonesia. All the new alkaloids have two alpha-methyl alpha,beta-unsaturated gamma-lactone moieties, while compound 2 also has an additional seven-membered ring, which has not been encountered before in Pandanus alkaloids. Two different extraction methods, namely, a solvent partitioning extraction and acid-base treatment, were tested, giving secondary and tertiary amines, respectively. Spectroscopic and chemical studies showed that the tertiary amines isolated from the acid-base treatment were artifacts formed during the extraction process. This finding suggests that the use of conventional acid-base treatment in isolating Pandanus alkaloids should be reviewed since it can introduce artifacts.     

New alkaloids from Daphniphyllum calycinum

Four new alkaloids, 17-hydroxyhomodaphniphyllic acid (1), daphcalycinosidine C (2, a new iridoid alkaloid), yuzurimine E (3), and yuzurimic acid B (4), were isolated from the seeds of Daphniphyllum calycinum. The structures of these Daphniphyllum alkaloids were determined by spectroscopic analysis including mass spectrometry and 2D NMR.     

New alkaloids from Cephalotaxus fortunei

Four new cephalotaxus alkaloids, cephalotaxine alpha-N-oxide (1), cephalotaxine beta-N-oxide (2), 11-beta-hydroxycephalotaxine beta-N-oxide (3), and isocephalotaxine (4), were isolated, together with several known alkaloids from an EtOAc extract of the fruits of Cephalotaxus fortunei. The structures were determined by spectral analysis including mass spectrometry and 2D NMR. Compounds 1, 2, 3, and 4 displayed cytotoxicity against nasopharynx KB cells with IC50 values of 30, 14, 31, and 15 micro g/mL, respectively.     

New alkaloids from Annona purpurea

Three new alkaloids, promucosine (1), romucosine F (2), and romucosine G (3), along with 28 known compounds, were isolated from the MeOH extract of stems of Annona purpurea. The structures of 1-3 were determined on the basis of spectral data and chemical evidence.     

New quinoline alkaloids from Ruta chalepensis

The roots of Ruta chalepensis, collected from the northern Saudi desert, yielded two new quinoline alkaloids, namely, 2-?6'-(2H-benzo[d]1' ',3' '-dioxolen-5' '-yl)hexyl?-hydroquinolin-4-one (1) and 2-?6'-(2H-benzo[d]1' ',3' '-dioxolen-5' '-yl)hexyl?-4-methoxy-quinoline (2). Nine previously reported alkaloids, dictamnine, pteleine, skimmianine, rutacridone, isogravacridonechlorine, maculosidine, graveoline, graveolinine, and 4-methoxy-1-methyl-2(1H)-quinolinone, and coumarins, chalepensin, and umbelliferone were also isolated. Structure elucidations were based primarily on 1D and 2D NMR analyses and chemical transformations. Antimicrobial activity of these compounds is discussed.     

New bisindole alkaloids from Tabernaemontana corymbosa

Ten new bisindole alkaloids of the vobasinyl-ibogan type, viz., conodiparines A-F (1-6), conodutarines A and B (7, 8), and cononitarines A and B (9, 10), were obtained from the leaf extract of the Malayan species Tabernaemontana corymbosa. The structures were determined using NMR and MS analysis.     

New tropane alkaloids from Erythroxylum moonii

Four new tropane alkaloids were isolated from the leaves of Erythroxylum moonii and identified as 3 alpha-isobutyryloxy-7 beta-hydroxynortropane (1), 3 alpha-hydroxy-7 beta-phenylacetoxynortropane (2), 3 alpha-cis-cinnamoyloxytropane (3), and 3 alpha-hydroxy-6 beta-(3'-hydroxy-2'-methyl-3'-phenylpropionyloxy)-7 beta-hydroxytropane (4). Other alkaloids isolated for the first time from E. moonii were 3 alpha-benzoyloxytropane, 3 alpha-phenylacetoxytropane, 3 alpha-trans-cinnamoyloxytropane, and 3 alpha-phenylacetoxy-6 beta,7 beta-dihydroxynortropane. The structures of compounds 1-4 were elucidated by spectroscopic methods.     

New diketopiperazine alkaloids from Penicillium fellutanum

Four new diketopiperazine alkaloids (1-4) were isolated from cultures of Penicillium fellutanum, and their structures were determined by MS and NMR measurements.     

New quinolizidine alkaloids from Ulex jussiaei

From an acidic extract of Ulex jussiaei four new quinolizidine alkaloids, jussiaeiines A (1), B (2), C (3), and D (4), were isolated and characterized by spectroscopic methods together with (-)-cytisine, (-)-N-methylcytisine, and (-)-anagyrine. The proposed biosynthetic origin of these new alkaloids is briefly discussed.