Cymodienol and cymodiene: new cytotoxic diarylheptanoids from the sea grass Cymodocea nodosa

The two new diarylheptanoids, cymodienol (1), and cymodiene (2), obtained from specimens of the sea grass Cymodocea nodosa, collected from the coastal areas of central Greece, are the first members of this class isolated from marine organisms. The chemical structures of the two metabolites were assigned on the basis of their NMR and MS spectroscopic data, including information obtained by 1D- and 2D-NMR experiments. Metabolite 2 possesses an unprecedented skeleton that might be biosynthetically related to metabolite 1. Cymodienol (1) was found to exhibit significant cytotoxic activity against two lung cancer cell lines.     

4个天然1,7-二芳基庚烷类化合物的合成

合成了4个天然1,7-二芳基庚烷类化合物:1-(4′-羟基-3′-甲氧基苯基)-7-(4″-羟基苯基)-5-羟基-3-庚酮(1),1-(4′-羟基-3′-甲氧基苯基)-7-(4″-羟基苯基)-4-庚烯-3-酮(2),1-(3′,4′-二羟基苯基)-7-(4″-羟基苯基)-5-羟基-3-庚酮(3),1-(3′,4′-二羟基苯基)-7-(4″-羟基苯基)-4-庚烯-3-酮(4).化合物1,2,4为首次合成.     

Diarylheptanoids from the Rhizomes of Alpinia officinarum

A novel dimeric diarylheptanoid, (5R,5′R)‐7,7′‐(6,6′‐dihydroxy‐5,5′‐dimethoxy[1,1′‐biphenyl]‐3,3′‐diyl)bis[5‐methoxy‐1‐phenylheptan‐3‐one] ( 1 ), and two new diarylheptanoids, (4E,6R)‐6‐hydroxy‐7‐(4‐hydroxy‐3‐methoxyphenyl)‐1‐phenylhept‐4‐en‐3‐one ( 2 ) and (4E,6R)‐6‐hydroxy‐1,7‐diphenylhept‐4‐en‐3‐one ( 3 ), together with seven known diarylheptanoids, were isolated from the rhizomes of Alpinia officinarum. Their structures were elucidated by application of extensive spectroscopic analyses and the modified Mosher method.     

Synthesis of Gingerenone C and 5-Hydroxy-1-(4'-hydroxy- 3'-methoxyphenyl)-7-(4"-hydroxyphenyl)-3-heptanone

The two diarylheptanoids (E)-1-(4'-hydroxy-3'-methoxyphenyl)-7-(4"-hydroxyphenyl) hept-4-en-3-one 1 (Gingerenone C) and (±)-5-hydroxy-1-(4'-hydroxy-3'-methoxyphenyl)-7-(4"-hydroxyphenyl)-3-heptanone 2 were synthesized from vanillin 3 and 4-hydroxybenzaldehyde 9.     

New Diarylheptanoids and Kavalactone from Alpinia katsumadai Hayata

Two new diarylheptanoids, katsumains A ( 1 ) and B ( 2 ), and one new kavalactone, katsumadain ( 3 ), together with the three known compounds (4E,6E)‐1,7‐diphenylhepta‐4,6‐dien‐3‐one ( 4 ), (5R,6E)‐1,7‐diphenyl‐5‐hydroxyhept‐6‐en‐3‐one ( 5 ), and cardamonin ( 6 ), were isolated from the seeds of Alpinia katsumadai Hayata . Their structures were elucidated mainly by spectroscopic methods (1D‐ and 2D‐NMR) and by mass spectrometry (HR‐ESI‐MS). Besides, the erroneous nomenclatures for (+)‐linderatin and (+)‐neolinderatin as given in [10] [11] were corrected to be 2′,4′,6′‐trihydroxy‐3′‐[(3R,4R)‐4‐isopropyl‐1‐methylcyclohex‐1‐en‐3‐yl]dihydrochalcone for (+)‐linderatin and 2′,4′,6′‐trihydroxy‐3′,5′‐bis[(3R,4R)‐4‐isopropyl‐1‐methylcyclohex‐1‐en‐3‐yl]dihydrochalcone for (+)‐neolinderatin, respectively.     

A short and efficient synthesis of renealtins A and B

The total syntheses of the first examples of diarylheptanoid natural products, renealtins A (1) and B (2), isolated from Renealmia exaltata are described, utilizing a δ-lactone intermediate 9. The key reactions involved are asymmetric dihydroxylation and oxy-Michael addition.     

Identification of Six New Minor Diarylheptanoids from the Seeds of Alpinia katsumadai

Phytochemical investigation of the seeds of Alpinia katsumadai (Zingiberaceae) led to the isolation and identification of six new diarylheptanoid derivatives, katsumains D–G ( 1 – 4 ), 3‐(acetyloxy)‐alpinikatin ( 5 ), and 5‐(acetyloxy)alpinikatin ( 6 ). The structures of 1 – 6 were elucidated by spectroscopic data analysis including 1D‐ and 2D‐NMR experiments.     

Stereoselective Total Synthesis of (3S,5S)‐1,7‐Bis(4‐hydroxyphenyl)heptane‐3,5‐diol, (3S,5S)‐Alpinikatin,and Its Diastereoisomers

Stereoselective synthesis of the diarylheptanoids, (3S,5S)‐1,7‐bis(4‐hydroxyphenyl)heptane‐3,5‐diol ( 1 ), (3S,5S)‐alpinikatin ( 3 ), and their diastereoisomers ( 2 and 4 , resp.), was achieved from readily available 4‐hydroxybenzaldehyde. The synthetic sequences involve Browns's allylation and Et₂Zn mediated diastereoselective alkynylation reaction as key steps.     

Preparative isolation and purification of antioxidative diarylheptanoid derivatives from Alnus japonica by high-speed counter-current chromatography

This study employed the online HPLC-2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS)(+) bioassay to rapidly determine the antioxidant compounds occurring in the crude extract of Alnus japonica. The negative peaks of the ABTS(+) radical scavenging detection system, which indicated the presence of antioxidant activity, were monitored by measuring the decrease in absorbance at 734 nm. The ABTS(+)-based antioxidant activity profile showed that three negative peaks exhibited antioxidant activity. High-speed counter-current chromatography (HSCCC) was used for preparative scale separation of the three active peaks from the extract. The purity of the isolated compounds was analyzed by HPLC and their structures were identified by (1)H- and (13)C-nuclear magnetic resonance spectrometry (NMR), heteronuclear multiple bond correlation (HMBC), and heteronuclear single quantum correlation (HSQC). Two solvent systems composed of n-hexane/ethylacetate/methanol/water (4:6:4:6, v/v) and of ethyl acetate/methanol/water (1:0.1:1, v/v) were performed in high-speed counter-current chromatography. Consequently, a total of 527 mg of hirsutanonol 5-O-β-D-glucopyranoside, 80.04 mg of 3-deoxohirsutenonol 5-O-β-D-glucopyranoside, and 91.0 mg of hirsutenone were obtained with purity of 94.7, 90.5, and 98.6%, respectively.     

Asymmetric syntheses of diarylheptanoid natural products (−)-centrolobine and (−)-de-O-methylcentrolobine via hetero-Diels-Alder reaction catalyzed by dirhodium(II) tetrakis[(R)-3-(benzene-fused-phthalimido)-2-piperidinonate]

Catalytic asymmetric syntheses of (−)-centrolobine and (−)-de-O-methylcentrolobine have been achieved, incorporating a hetero-Diels-Alder (HDA) reaction between 4-aryl-2-silyloxy-1,3-butadienes and phenylpropargyl aldehyde derivatives as a key step. The HDA reaction using dirhodium(II) tetrakis[(R)-3-(benzene-fused-phthalimido)-2-piperidinonate], Rh₂(R-BPTPI)₄, as a chiral Lewis acid catalyst provides exclusively cis-2,6-disubstituted tetrahydropyran-4-ones in up to 93% ee.