New norditerpenoid alkaloids from Aconitum hemsleyanum var. leueanthus

Four new norditerpenoid alkaloids, leueantines A (1), B (2), C (3), and D (4), were isolated from the roots of Aconitum hemsleyanum var. leueanthus. The structures of 1-4 were established by spectroscopic evidence.     

Three new toxic norditerpenoid alkaloids from the low larkspur Delphinium nuttallianum

Three new N-(methylsuccinimido)anthranoyllycoctonine norditerpenoids, given the names bearline (1), 14-acetylbearline (2), and 16-deacetylgeyerline (3), were isolated from the extract of the low larkspur Delphinium nuttallianum. The structures of the individual alkaloids were determined by (1)H and (13)C NMR spectroscopy and HRMS. These alkaloids are structurally related to the neurotoxic alkaloid methyllycaconitine (4) and may be important in establishing the toxicity of low larkspurs to cattle. A mouse bioassay was used to measure the LD(50) values for two of the new alkaloids (1 and 2), as sufficient quantities of 3 were not available for toxicity testing. A structurally related alkaloid, geyerline (7), was isolated from D. geyeri in sufficient quantities for toxicity testing. The toxicities of 1, 2, and 7 were found to be comparable to that of 4, with calculated LD(50) values in mice of 5.7, 3.3, and 6.2 mg/kg, respectively.     

Diterpenoid alkaloids from the lateral root of Aconitum carmichaelii

Twenty-six new diterpenoid alkaloids, 1-26 (1-4: hetisan-type C(20)-diterpenoid alkaloids; 5-26: aconitane C(19)-diterpenoid alkaloids), and two known analogues, hypaconitine 27 and benzoylmesaconine 28, have been isolated from a water extract of the lateral root of Aconitum carmichaelii. Compounds 7 and 8 are rare examples of conformational isomers obtained from the same material. The conformation and conformational transformation of ring A in the C(19)-diterpenoid alkaloids are discussed on the basis of NMR data analysis in combination with single-crystal X-ray crystallography of 6 and 27 by anomalous scattering of Cu Kα radiation. In preliminary analgesic and toxicity assays, the isomer with ring A in the chair conformation (8 or 27) was found to be more active than that with ring A in the boat conformation (7 or 27a). In addition, 15, 16, and 19 showed neuroprotective activity.     

铁棒锤及其炮制品中二萜生物碱化学成分研究

目的研究铁棒锤及其水煮炮制品的化学成分。方法采用硅胶柱色谱等方法对铁棒锤及水煮炮制品的化学成分进行分离纯化,根据化合物的理化常数和波谱数据鉴定其结构。结果从铁棒锤及其水煮炮制品中共分离得到12个化合物,经鉴定为去氧乌头碱(1)、3-乙酰乌头碱(2)、乌头碱(3)、15α-OH-neoline(4)、8-acetyl-15-hydroxyneoline(5)、尼奥灵(6)、14-benzoyl-8-O-methylaconine(7)、苯甲酰乌头原碱(8)、多裂乌头碱D(polyschistineD,9)、苯甲酰去氧乌头碱(10)、polyschistineA(11)、乌头原碱(12)。结论二萜生物碱是铁棒锤块根的主要化学成分,其中化合物4～8为首次从该植物中分离得到。与生品相比,铁棒锤水煮炮制品中二萜生物碱成分发生了一定的变化,其中化合物9～12为炮制品新增的成分,这些成分的鉴定为铁棒锤水煮炮制法炮制原理的揭示提供了依据。     

C19-diterpenoid alkaloids from Aconitum hemsleyanum var. circinatum

Seven new C19-diterpenoid alkaloids, circinasines A-G (1-7), together with six known compounds, talatisamine, yunaconitine, senbusine A, sachaconitine, hemsleyanisine, and isohemsleyanisine, were isolated from the roots of Aconitum hemsleyanum var. circinatum. The structures of 1-7 were determined by the interpretation of spectroscopic data and by the single-crystal X-ray crystallographic analysis of 6 and the acetonide derivative of 1. In addition, the structures of hemsleyanisine and isohemsleyanisine were revised from 8 and 9 to 10 and 11, respectively.     

Hetisine-type diterpenoid alkaloids from the Bhutanese medicinal plant Aconitum orochryseum

Investigation of Aconitum orochryseum, a Bhutanese traditional medicine ("gSo-ba Rig-pa") plant locally known as "Bong-kar", resulted in the isolation of three new hetisine-type diterpenoid alkaloids, named orochrine (1), 2-O-acetylorochrine (2), and 2-O-acetyl-7alpha-hydroxyorochrine (3), together with the previously reported alkaloids atisinium chloride (4) and virescenine (5). The structures of the new alkaloids were elucidated by spectroscopic data analysis.     

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.