ABSTRACT
Natural products are the important source for the discovery of more potent anti-HIV agents. In this study, six daphnane diterpenoids including three unreported structures were isolated from Trigonostemon lii, which showed significant activities against HIV-1 strains replication in the nanomolar/picomolar range. Meanwhile, these diterpenoids significantly inhibited the fusion of H9/HIV-1 IIIB cells with uninfected C8166 cells, with the EC50s from 1.06 to 8.73 ng/mL, and did not show any inhibition activities against HIV-1 reverse transcriptase. Moreover, all of the diterpenoids shows significant inhibitions against T20-resistan HIV-1 strains, PNL4-3gp41(36G)V38E, N42S and pNL4-3gp41(36G)V38A, N42T. The results revealed that the six diterpenoids could be a new type of potential lead candidate as an HIV entry inhibitor, particularly for those infected by T20-resistant variants.
ABSTRACT
Ochrocephalamines B-D (1-3), composed of fused quinolizidine and octahydroquinoline rings, were isolated from Oxytropis ochrocephala Bunge. Ochrocephalamine B (1) has a unique bridged tetracyclic ring skeleton fused with a lactam ring. The structures of 1-3 were elucidated using spectroscopic and computational approaches. Ochrocephalamine C (2) and D (3) demonstrated potent anti-HBV activities and are more potent against the secretion of HBeAg than that of HBsAg.
Subject(s)
Alkaloids/chemistry , Oxytropis/chemistry , Models, Molecular , Molecular ConformationABSTRACT
Ten alkaloids (1-10), with sophoridine (1) as the most abundant component, were obtained from the whole plants of Oxytropis ochrocephala Bunge. Furthermore, eight new sophoridine derivatives (11-16, 20, 21), with modification on the C-14 position of 1 were synthesized. All compounds (1-16, 20, 21) were evaluated for antiproliferative activity against five human tumor cell lines. Among them, the newly synthesized derivative 20 exhibited the best inhibitory activity against the tested cell lines. Its activity was increased by more than fourfold as compared with parent compound 1.
Subject(s)
Alkaloids/chemistry , Alkaloids/pharmacology , Antineoplastic Agents, Phytogenic/chemistry , Antineoplastic Agents, Phytogenic/pharmacology , Oxytropis/chemistry , Quinolizines/chemistry , Alkaloids/isolation & purification , Antineoplastic Agents, Phytogenic/isolation & purification , Cell Line, Tumor , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Humans , Molecular Structure , Structure-Activity Relationship , MatrinesABSTRACT
One dimeric matrine-type alkaloid, ochrocephalamine A (1), was isolated from the poisonous plant Oxytropis ochrocephala Bunge. Its structure was elucidated by spectroscopic data and single-crystal X-ray diffraction. The insecticidal and cytotoxic activities of 1 were evaluated.
ABSTRACT
Two degraded diterpenoids, thrigonosomones D and E, were isolated from the stems of Trigonostemon lii. Their structures were established by spectroscopic methods, including extensive 1D- and 2D-NMR experiments.
Subject(s)
Diterpenes/chemistry , Euphorbiaceae/chemistry , Plant Stems/chemistry , Magnetic Resonance Spectroscopy , Molecular StructureABSTRACT
A phytochemical work on the alkaloid constituents from Trigonostemon lii Y.T. Chang was conducted to give six new ß-carboline alkaloids, trigonostemines A-F (1-6) and eight known ß-carboline alkaloids (7-14). Their structures were elucidated by extensive spectroscopic techniques including 2D NMR experiments and mass spectrometry. All of the compounds were evaluated for their cytotoxic activities against the HL-60, SMMC-7721, A-549, MCF-7, and SW480 human cancer cell lines. Trigonostemines A and B (1 and 2) exhibited stronger inhibitory activities than the positive control (cisplatin) in some cell lines.
Subject(s)
Antineoplastic Agents, Phytogenic/chemistry , Carbolines/chemistry , Euphorbiaceae/chemistry , Indole Alkaloids/chemistry , Antineoplastic Agents, Phytogenic/pharmacology , Carbolines/pharmacology , Cell Line, Tumor , Cell Survival/drug effects , Cisplatin/pharmacology , Drug Screening Assays, Antitumor , Humans , Indole Alkaloids/pharmacology , Magnetic Resonance Spectroscopy , Mass Spectrometry , Plant Extracts/chemistry , Plant Leaves/chemistryABSTRACT
Three unprecedented indole alkaloids, trigonoliimines A-C (1-3) with a unique polycyclic system, were isolated from the leaves of Trigonostemon lii Y. T. Chang. The structures of 1-3 were determined by the spectroscopic, computational, and CD exciton chirality approaches. Trigonoliimine A showed modest anti-HIV-1 activity (EC(50) = 0.95 microg/mL, TI = 7.9).
Subject(s)
Anti-HIV Agents/isolation & purification , Euphorbiaceae/chemistry , Indole Alkaloids/isolation & purification , Anti-HIV Agents/chemistry , Anti-HIV Agents/pharmacology , HIV-1/drug effects , Indole Alkaloids/chemistry , Indole Alkaloids/pharmacology , Microbial Sensitivity Tests , Molecular Conformation , Plant Leaves/chemistry , StereoisomerismABSTRACT
Daphhimalenine A (1), a novel alkaloid with a rearrangement C-21 skeleton, containing a unique 1-azabicyclo[5.2.1]decane ring system, was isolated from the leaves of Daphniphyllum himalense, along with biogenetically related alkaloids daphhimalenine B (2) and daphnezomine T. Their structures were established on the basis of spectroscopic data, and the absolute configuration of 1 was assigned by computational methods. A plausible biosynthetic pathway of 1 was also proposed.
Subject(s)
Alkaloids/chemistry , Alkaloids/isolation & purification , Saxifragaceae/chemistry , Alkaloids/pharmacology , Drug Screening Assays, Antitumor , Humans , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular , Plant Leaves/chemistryABSTRACT
Four new Daphniphyllum alkaloids, dapholdhamines A-D (1-4), were isolated from the leaves of Daphniphyllum oldhami. The structures and relative configurations of 1-4 were elucidated on the basis of spectroscopic data.
Subject(s)
Alkaloids/isolation & purification , Drugs, Chinese Herbal/isolation & purification , Saxifragaceae/chemistry , Alkaloids/chemistry , Drugs, Chinese Herbal/chemistry , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular , Plant Leaves/chemistryABSTRACT
A new alkaloid, daphenylline (1), with an unprecedented rearranged 22-nor-calyciphylline skeleton, was isolated from the fruits of Daphniphyllum longeracemosum. Its structure and stereochemistry were elucidated on the basis of spectroscopic and computational approaches. A plausible biosynthetic pathway of 1 was also proposed.