Two New Limonoids from the Root Bark of Chinese Medicinal Plant Dictamnus dasycarpus

Two new limonoids, kihadanin C ( 1 ) and 23‐methoxydasylactone A ( 2 ), together with seven related known ones, 3 – 9 , were isolated from the root bark of the plant Dictamnus dasycarpus. The structures of the new compounds were elucidated on the basis of extensive analyses of their spectroscopic data (1D‐ and 2D‐NMR, MS) and by comparison of their NMR data with those reported in the literature. To the best of our knowledge, 1 presents the first example of A,D‐seco limonoid with an unusual 3,4‐dihydroxy‐2,5‐dimethoxytetrahydrofuran moiety as ring E. In the bioassay in vitro, 7 showed moderate antibacterial activity against Staphylococcus aureus, while 8 and 9 displayed neuroprotective activities against H₂O₂‐induced injury in SH‐SY5Y cells.     

Two New C20‐Diterpenoid Alkaloids from Aconitum carmichaelii

Two new C₂₀‐diterpenoid alkaloids, named aconicarchamines A and B ( 1 and 2 , resp.), were isolated from Aconitum carmichaelii. By UV, IR, MS, and 1D‐ and 2D‐NMR analyses, their structures were elucidated as 14,17‐dihydro‐14,17‐dihydroxyajabicine and 15‐O‐acetyllassiocarpine. Compound 1 is the third C₂₀‐diterpenoid alkaloid with the lycoctine skeleton bearing an exocyclic C‐atom at C(14).     

Two New Lycopodine Alkaloids from Huperzia serrata

Two new lycopodine alkaloids, (12β)‐12‐hydroxyhuperzine G ( 1 ) and (5β,6β,15α)‐15‐methyllycopodane‐5,6‐diol ( 2 ), were isolated from the whole plants of Huperzia serrata, together with six known compounds, huperzines A, B, and G, phlegmariurine B, (8β)‐8‐hydroxyphlegmariurine B, and lycoposerramine D. Their structures were elucidated on the basis of spectroscopic analysis, including HR‐ESI‐MS, ¹H‐ and ¹³C‐NMR, DEPT, ¹H,¹H‐COSY, HSQC, HMBC, and NOESY data.     

Diastereoisomeric ent‐Labdane Diterpenoids from Andrographis paniculata

Four C(8),C(12)‐diastereoisomers, (8S,12S)‐isoandrographolide ( 1 ), (8S,12R)‐isoandrographolide ( 2 ), (8R,12R)‐isoandrographolide ( 3 ), and (8R,12S)‐isoandrographolide ( 4 ) were isolated from the aerial parts of Andrographis paniculata. The structures of the new compounds 1 – 3 were established on the basis of the spectroscopic data including UV, IR, NMR, HR‐ESI‐MS, and X‐ray diffraction analysis.     

Unusual open chain quinolinyl peroxol and its alcohol counterpart obtained through a modified Skraup–Doebner–Von Miller quinoline synthesis: theoretical studies and complete 1H‐ and 13C‐NMR assignments

Because of their extreme instability, it is generally difficult to synthesize and fully characterize open chain peroxides, also known as peroxols. In our attempt to investigate the mechanism of the Skraup–Doebner–Von Miller quinoline synthesis, we were able to obtain an unusual open chain peroxy‐quinoline, namely, 4‐(8‐ethoxy‐2,3‐dihydro‐1H‐cyclopenta[c]quinolin‐4‐yl)butane‐1‐peroxol (1), and its alcohol counterpart, namely 4‐(8‐ethoxy‐2,3‐dihydro‐1H‐cyclopenta[c]quinolin‐4‐yl)butan‐1‐ol (2) obtained as a side product during the same reaction. Although structurally similar, these two compounds appeared to display some very distinct physical and spectroscopic characteristics. This work reports detailed NMR studies and full ¹H and ¹³ C NMR assignments for these two compounds. These assignments are based upon the analysis of the NMR spectra of these compounds including ¹H, ¹³ C, COSY, gHSQC and gHMBC. The effect of the peroxide functional group on the chemical shift of neighboring carbons and protons was also investigated by comparing the NMR data of these two compounds. Furthermore, the effects of potential hydrogen bondings in 1, 2, and possible 1–1 dimer, 2–2 dimer and in prototypical model systems, as well as the stability of these compounds, were investigated computationally. The computed dissociation energies and NMR data support the interpretation of the experimental data. Copyright © 2012 John Wiley & Sons, Ltd.     

A New Megastigmane Palmitate and a New Oleanane Triterpenoid from Aster yomena Makino

A new megastigmane palmitate, 9‐oxomegastigm‐5(13)‐ene‐2β‐palmitate ( 1 ), and a new oleanane triterpenoid, (3β)‐3,23,28‐trihydroxyolean‐12‐en‐11‐one ( 2 ), together with three known oleanane‐type triterpenoids, β‐amyrin ( 3 ), erythrodiol ( 4 ), and (3β)‐olean‐12‐ene‐3,23,28‐triol ( 5 ), were isolated from the aerial parts of Aster yomena (Asteraceae). Their structures were identified based on 1D‐ and 2D‐NMR analysis, including ¹H,¹H‐COSY, HSQC, HMBC, and NOESY techniques.     

Photo‐Fries Rearrangement of Carbazol‐2‐yl Sulfonates: Efficient Tool for the Introduction of Sulfonyl Groups into Polycyclic Aromatic Compounds

Systematic studies on the photo‐Fries rearrangement of different 9H‐carbazol‐2‐yl sulfonates 2 have shown that this type of conversion can be readily used for the preparative‐scale introduction of alkyl‐ or arylsulfonyl groups into polycyclic aromatic compounds under very mild conditions. A series of new 1‐sulfonyl‐ ( 3 ) or 3‐sulfonyl‐9H‐carbazoles ( 4 ) were prepared in medium‐to‐good yields, and characterized by UV/VIS, ¹H‐NMR, and ¹³C‐NMR spectroscopy, as well as by elemental analysis. Effects of irradiation wavelength, solvent polarity, presence or absence of O₂, and photosensitizers were studied in detail.     

Furanone Derivatives from Aspergillus sp. XW‐12, an Endophytic Fungus in Huperzia serrata

Two new 5‐methoxyfuran‐3(2H)‐one derivatives, huaspenone A ( 1 ) and B ( 2 ), together with four known ones, i.e., aspertetronin A ( 3 ), aspertetronin B ( 4 ), gregatin E ( 5 ), and penicilliol A ( 6 ), were isolated from the cultures of an endophytic fungus Aspergillus sp. XW‐12, derived from the stems of Huperzia serrata. The structures of the new isolates were established by detailed interpretation of the 1D‐ and 2D‐NMR and HR‐ESI‐MS data.     

neo‐Clerodane Diterpenoids from the Aerial Part of Scutellaria barbata

Three new neo‐clerodane diterpenoids, barbatellarines C–E ( 1 – 3 ), were isolated from the CHCl₃‐soluble fraction of the aerial part of Scutellaria barbata. Their chemical structures were elucidated by detailed analysis of NMR and MS data. Compounds 1 and 2 were C(13) epimers, which was confirmed by an NOE difference experiment and the NOESY spectrum. The relative configuration was determined on the basis of the ¹H‐NMR J‐value and NOE data, while the absolute configuration of the previously isolated analogue, barbatellarine B ( 4 ), as a representative member of the group, was assigned by CD analysis.     

Alkaloids from Lindera Glauca

A new amide, N‐cis‐sinapoyltyramine ( 1 ), and twelve known compounds were isolated from the aerial parts of Lindera glauca. The structure of the new compound has been established by the study of extensive 2D NMR data.     

Salicassin,an Unprecedented Chalcone?Diterpene Adduct and a Quinone Methide Triterpenoid from Maytenus salicifolia

In continuation of our work on Maytenus salicifolia, we report herein the isolation and structural elucidation of two new compounds, salicassin ( 1 ), a diterpene‐chalcone adduct with an unprecedented C‐framework, and (16β)‐16‐hydroxypristimerin ( 2 ), a quinone methide triterpenoid. Their structures were elucidated on the basis of spectroscopic analysis, including 1D‐ and 2D‐NMR techniques (COSY, ROESY, HSQC, and HMBC). In addition, 22 known compounds were isolated and characterized by comparison of their spectra with reported data. Compound 2 , structurally related to the well known cytotoxic quinone methide triterpenoids, exhibited an antiproliferative effect on HeLa, A‐549, and HL‐60 human cell lines, with IC₅₀ values of 2.2, 3.2, and 2.7 μM , respectively.     

A New Pregnane and a New Diphenylmethane from the Root Barks of Periploca sepium

A new polyoxygenated pregnane genin and a new diphenylmethane, along with five known pregnane derivatives, were isolated from the root barks of Periploca sepium. The structures of the new compounds were elucidated as (3β,14β)‐3,14‐dihydroxy‐21‐methoxypregn‐5‐en‐20‐one ( 1 ) and 2‐hydroxy‐5‐(2‐hydroxy‐4‐methoxybenzyl)‐4‐methoxybenzaldehyde ( 2 ) on the basis of spectroscopic methods, especially 2D‐NMR and MS analyses. The known compounds were identified by comparing their physical and spectroscopic data with those reported in the literature.     

1‐Aminoindan‐2‐ol,a Suitable Ligand for the Synthesis of Chiral,Intramolecularly Stabilized Compounds of Aluminum,Gallium, and Indium

The reactions of enantiomerically pure (1R, 2S)‐(+)‐cis‐1‐aminoindan‐2‐ol, (1S, 2R)‐(‐)‐cis‐1‐aminoindan‐2‐ol, and racemic trans‐1‐aminoindan‐2‐ol with trimethylaluminum, ‐gallium, and ‐indium produce the intramolecularly stabilized, enantiomerically pure dimethylmetal‐1‐amino‐2‐indanolates (1R, 2S)‐(+)‐cis‐Me₂AlO‐2‐C*HC₇H₆‐1‐C*HNH₂ ( 1 ), (1S, 2R)‐(‐)‐cis‐Me₂AlO‐2C*HC₇H₆‐1‐C*HNH₂ ( 2 ), (1R, 2S)‐(+)‐cis‐Me₂GaO‐2‐C*HC₇H₆‐1‐C*HNH₂ ( 3 ), (1R, 2S)‐(+)‐cis‐Me₂InO‐2‐C*HC₇H₆‐1‐C*HNH₂ ( 4 ), (1S, 2R)‐(‐)‐cis‐Me₂InO‐2‐C*HC₇H₆‐1‐C*HNH₂ ( 5 ), and racemic (+/‐)‐trans‐Me₂InO‐2‐C*HC₇H₆‐1‐C*HNH₂ ( 6 ). The compounds were characterized by ¹H NMR, ¹³C NMR, ²⁷Al NMR and mass spectra as well as 1 and 3 to 6 by determination of their crystal and molecular structures. The dynamic dissociation/association behavior of the coordinative metal‐nitrogen bond was studied by low temperature ¹H NMR spectroscopy.     

Biotransformation of Vermitaline by Cunninghamella echinulata

Biotransformation of vermitaline ( 1 ) by Cunninghamella echinulata (ACCC 30369) was carried out. Four biotransformation products were obtained and three of them were characterized as new compounds. On the basis of their NMR and mass‐spectral data, their structures were characterized as 7α‐hydroxyrubijervine ( 2 ), 7α‐hydroxyrubijervine‐7‐O‐β‐D ‐galactofuranoside ( 3 ), 7α‐hydroxyvermitaline ( 4 ), and 7α‐hydroxyvermitaline‐7‐O‐β‐D ‐galactofuranoside ( 5 ).     

Three New C19‐Diterpenoid Alkaloids from Aconitum forrestii

A further study of the alkaloid constituents of Aconitum forrestii led to the isolation of three new C₁₉‐diterpenoid alkaloids, named 14‐acetoxy‐8‐O‐methylsachaconitine ( 1 ), 14‐acetoxyscaconine ( 2 ), and 8‐O‐ethylcammaconine ( 3 ). Their structures were determined by UV, IR, and MS, 1D‐ and 2D‐NMR analyses.     

Three New Caged Prenylxanthones from Garcinia bracteata

Three new caged prenylxanthones (xanthone=9H‐xanthen‐9‐one), named neobractatin ( 1 ), 3‐O‐methylneobractatin ( 2 ), and 3‐O‐methylbractatin ( 3 ), along with eight known compounds, were isolated from the twig of Garcinia bracteata. The structures of the new compounds were elucidated on the basis of 1D‐ and 2D‐NMR experiments, including HMBC, HSQC, ¹H,¹H‐COSY, and ROESY, as well as HR‐MS analysis.     

Three New Pregnane Alkaloids from Veratrum taliense

Three new alkaloids, 3‐O‐acetylveralkamine ( 1 ), veralkamine 3‐(β‐D ‐glucopyranoside) ( 2 ), and 6,7‐epoxyverdine ( 3 ), together with five known alkaloids, veramitaline, veralkamine ( 4 ), angeloylzygadenine, veratroylzygadenine, and veramiline 3‐(β‐D ‐glucopyranoside), were isolated from the whole plants of Veratrum taliense. Their structures were elucidated on the basis of spectroscopic analysis, and the NMR data of veralkamine ( 4 ) are given for the first time. In addition, the cytotoxic activities of all isolated compounds, except for veramitaline, were tested.     

A New Glycine Derivative and a New Indole Alkaloid from the Fermentation Broth of the Plant Endophytic Fungus Pestalotiopsis podocarpi Isolated from the Chinese Podocarpaceae Plant Podocarpus macrophyllus

A new glycine derivative, podocarpiamide ( 1 ), a new indole alkaloid, 1‐methoxy‐1H‐indol‐3‐ethanol ( 2 ), together with two known compounds, 1‐methoxy‐1H‐indole‐3‐acetic acid ( 3 ) and methyl 1‐methoxy‐1H‐indole‐3‐acetate ( 4 ), were isolated from the fermentation broth of the plant endophytic fungus Pestalotiopsis podocarpi. Their structures were elucidated by extensive spectroscopic analysis including 1D‐ and 2D‐NMR (HSQC, HMBC, and COSY) and MS experiments. Compound 1 has an interesting unusual carbamic acid structure.     

Phenylpropanoid‐Substituted Catechins and Epicatechins from Smilax china

The four new phenylpropanoid‐substituted catechins 1, 3 , and 4 and 3‐epicatechin ( 2 ), together with seven analogues, were isolated from the AcOEt extract of Smilax china L. (catechin=(2R,3S)‐2‐(3,4‐dihydroxyphenyl)‐3,4‐dihydro‐2H‐2‐benzopyran‐3,5,7‐triol). Their structures were determined by means of spectroscopic analyses, including HR‐MS, IR, ¹H‐ and ¹³C‐NMR, and 2D experiments (COSY, HSQC, and HMBC), and comparison with known related compounds.     

A new Sequiterpenoid from Eupatorium adenophorum Spreng

A new sequiterpenoid compound 8aα-hydroxy-1-isopropyl-4,7-dimethyl-1,2,3,4,6,8a-hexahydro-naphthalene-2,6-dione(1),together with seven known compounds anti-HH-dimer-coumarin(2),(-)-5-exo-hydroxy-bomeol(3),O-hydroxyl cinnamic acid(4),9β-hydroxy-ageraphorone(5),10Hα-9-oxo-ageraphorone(6),10Hβ-9-oxo-ageraphorone(7)and 9-oxo-10,11-dehydroageraphorone 8,was isolated from the leaves of Eupatorium adenopho-rum Spreng.The structures were elucidated by IR,~1H and ~(13)C NMR,EIMS,HMBC and single-crystal X-ray spec-tral data.