One new and several minor diarylheptanoids from Amomum muricarpum

A new natural diarylheptanoid, designated muricarpin, together with four diarylheptanoids were isolated from the rhizomes of Amomum muricarpum Elmer (Zingiberaceae) growing in Vietnam. Three known compounds, 1,7-bis(3,4-dihydroxyphenyl)heptan-3-yl acetate, 1-(4'-hydroxyphenyl)-7- (3″,4″-dihydroxyphenyl)heptan-3-yl acetate and 1-(3',4'-dihydroxyphenyl)-7-(4″-hydroxyphenyl)-heptan-3-one were isolated for the first time from the genus Amomum, meanwhile (5R)-5-hydroxy-1,7-bis(4-hydroxyphenyl)-heptan-3-one was found for the first time in plants. Their structures were determined using spectroscopic analyses.     

Synthesis of 1-(3',4'-dihydroxyphenyl)-7-(4"-hydroxyphenyl)- 4hepten-3-one

Natural diarylheptanoids have significant bioactivities. Some of them are potent inhibitors against prostaglandin biosynthesizing enzyme (PG synthetase) and 5-lipoxygenase (LT synthetase)1-2. Compound 1 was firstly isolated from Alnus rubra bark3. So far its synthesis has not been reported yet. Herein, we report the synthesis of compound 1. Meantime, compound 24 was also obtianed as an intermediate. Compound 7 and 16 were converted to compound 10 and 18 respectively, because compound 1…     

Synthesis of Two Alnustone-Like Natural Diarylheptanoids via 4 + 3 Strategy

The first total synthesis of (4E,6E)-1,7-bis(3,4-dihydroxyphenyl)-hepta-4,6-dien-3-one and an alternative synthesis of (4E,6E)-1,7-bis(4-hydroxyphenyl)-hepta-4,6-dien-3-one, two natural diarylheptanoids, mainly based on Claisen–Schmidt condensation were described. The crucial steps of the syntheses were the condensation of OH-protected 4-aryl-2-butanones with OH-protected 3-aryl-acrylaldehydes by the in situ enamination and then deprotection of OH groups to give the corresponding natural diarylheptanoids.     

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.     

Three new diarylheptanoids and their antioxidant property

Three new diarylheptanoids,i.e.,sodium(5S,2E)-1,7-bis(4-hydroxyphenyl)-1-hydroxy-2-hepten-5-sulfonate(1), sodium(5R,2E)-1,7-bis(4-hydroxyphenyl)-1-hydroxy-2-hepten-5-sulfonate (2) and 3,5-diacetoxy-1-(3-methoxy-4,5-dihydroxy- phenyl)-7-(4-hydroxy-3-methoxyphenyl)heptane (3) were isolated from the rhizomes of Zingiber officinale.The structures of the new compounds were elucidated on the basis of spectroscopic methods.The antioxidant activities of 3 were assayed by in vitro models involving DPPH free radicals and superoxide anion radicals.     

Microbial metabolism. Part 7 : Curcumin

Microbial metabolism of the cancer chemopreventive agent, curcumin [(1E,6E)-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,6-diene-3,5-dione] (1) with Pichia anomala (ATCC 20170) yielded four major metabolites, 5-hydroxy-1,7-bis(4-hydroxy-3-methoxyphenyl)heptan-3-one (2), 5-hydroxy-7-(4-hydroxy-3-methoxyphenyl)-1-(4-hydroxyphenyl)heptan-3-one (3), 1,7-bis(4-hydroxy-3-methoxyphenyl)heptan-3,5-diol (4), 5-hydroxy-1,7-bis(4-hydroxyphenyl)heptane-3-one (5) and two minor products, 1-(4-hydroxy-3-methoxyphenyl)-7-(4-hydroxyphenyl)heptane-3,5-diol (6) and 1,7-bis(4-hydroxyphenyl)heptane-3,5-diol (7). The structures of compounds 2-5 were established on the basis of spectroscopic data. Compounds 6 and 7 were assigned tentative structures.     

In vitro and ex vivo antitubercular activity of diarylheptanoids from the rhizomes of Alpinia officinarum Hance

Phytochemical investigation of methanol extract of the rhizomes of Alpinia officinarum Hance afforded four known diarylheptanoids 1,7-diphenylhept-4-en-3-one (1), 5-hydroxy-1,7-diphenyl-3-heptanone (2), 5-hydroxy-7-(4″-hydroxy-3″-methoxyphenyl)-1-phenyl-3-heptanone (3), and 7-(4″-hydroxy-3″-methoxyphenyl)-1-phenyl heptan-3-one (4).The acetate derivative of (4), 7-(4″-actetate-3″-methoxy phenyl)-1-phenyl heptan-3-one (5), was prepared. These diarylheptanoids exhibited promising in vitro and ex vivo antitubercular activity for the first time against dormant Mycobacterium tuberculosis H37Ra with the IC₅₀ values between 0.34–47.69 and 0.13–22.91 μM, respectively. All compounds showed comparable activity against Mycobacterium bovis BCG (dormant phage) and did not show any activity against two gram + ve and two gram –ve bacterial strains. These compounds were also weakly cytotoxic up to 300 μM against three human cancer cell lines THP-1, Panc-1 and A549.     

Synthesis of some imidazole- and pyrazole- derived chelating agents

Procedures involving condensation of o-phenylenediamines with carboxylic acids, and reaction of bifunctional alkyl halides with bifunctional nucleophiles are described. Syntheses are reported of 2,6-bis-(2-benzimidazyl)-pyridine, 1,3-bis(2-benzimidazyl)-2-thiapropane, 1,7-bis(2-benzimidazyl)-2,6-dithiaheptane, 2-hydroxymethyl-5,6-dimethylbenzimidazole, 2-chloromethyl-5,6-dimethylbenzimidazole hydrochloride, 1,7-bis(5,6-dimethyl-2-benzimidazyl)-2,6-dithiaheptane, 3,6-bis(1-pyrazolyl)pyridazine, 2-(2-hydroxy-3-methyl–phenyl)benzimidazole, 2-(2-hydroxyphenyl)benzimidazole, 5-(2-hydroxphenyl)-3-methyl-1-phenylpyrazole, 3(5)-(2-hydroxyphenyl)-5(3)-methylpyrazole, 3(5)-(2-hydroxyphenyl)-5(3)-phenylpyrazole, and 1,3-bis((5-methylpyridyl)imino)isoindoline.     

New phenolic principles from Hypericum sampsonii

Using the anti-hepatitis B virus (HBV)-producing cell line MS-G2 in vitro cultural system-guided screening was performed, and two new benzophenones, 2,6-dihydroxy-4-[(E)-5-hydroxy-3,7-dimethylocta-2,7-dienyloxy]benzophenone (1) and 2,6-dihydroxy-4-[(E)-7-hydroxy-3,7-dimethylocta-2-enyloxy]benzophenone (2), a new xanthone, hyperxanthone (3), a new bisanthraquinone glycoside, R-(-)-skyrin-6-O-beta-D-xylopyranoside (4), and 2-caffeoyloxy-3-hydroxy-3-(3,4-dihydroxyphenyl)propyl alcohol (5), and 16 known compounds were isolated from the anti-HBV active fraction of the whole herbs of Hypericum sampsonii. Their structures were elucidated using spectroscopic methods, mainly 2D NMR and MS spectrometry. Circular dichroism was used to determine the stereochemistry of bisanthraquinone glycosides.     

A new diarylheptanoid from Alpinia officinarum promotes the differentiation of 3T3-L1 preadipocytes

A new diarylheptanoid, namely trans-(4R,5S)-epoxy-1,7-diphenyl-3-heptanone (1), and a new natural product, 7-(4″-hydroxy-3″-methoxyphenyl)-1-phenyl-hepta-4E,6E-dien-3-one (2), were obtained from the aqueous extract of Alpinia officinarum Hance, together with three other diarylheptanoids, 5-hydroxy-1,7-diphenyl-3-heptanone (3), 1,7-diphenyl-4E-en-3-heptanone (4) and 5-methoxy-1,7-diphenyl-3-heptanone (5). The structures were characterised mainly by analysing their physical data including IR, NMR and HRMS. This study highlights that the 4,5-epoxy moiety in 1 is rarely seen in diarylheptanoids. In addition, the five isolates were tested for their differentiation activity of 3T3-L1 preadipocytes. The results showed that these compounds could dose-dependently promote adipocyte differentiation without cytotoxicity (IC₅₀ > 100 μM).     

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.     

The antioxidative potential of benzofuran-stilbene hybrid derivatives: a comparison between natural and synthetic compounds

Structural Chemistry - The antioxidative activity of natural product compound amurensin H (1) and its three synthetic compounds 5-(6-hydroxy-2-(4-hydroxyphenyl)benzofuran-3-yl)benzene-1,3-diol (2),...     

Antifungal agent and other constituents from Cynanchum otophyllum

Seven constituents were isolated from the ethyl acetate extract of the rhizome of Cynanchum otophyllum Schneid (Asclepiadaceae). Their structures were determined as 1-(4-methoxy-3-(6-methoxy-3-acetylphenylperoxy)phenyl)ethanone (1), 1-(3-hydroxy-7-acetylnaphthalen-2-yl)ethanone (2), 1-(3,4-dihydroxyphenyl)ethanone (3), 1-(2,4-dihydroxyphenyl)ethanone (4), 1-(3-(3,6-dihydroxy-2-methylbenzoyl)-2,4-dihydroxyphenyl)ethanone (beishouwubenzophenone) (5), N,N-dimethylethanamine (6), and 2-oxo-2-phenylacetic acid (7), respectively, by spectral methods. Among them, 1 and 2 were new compounds; 1 had antifungal activity.     

Herbicidal activity of flavonoids of mango leaves against Parthenium hysterophorus L

This study was undertaken to investigate the herbicidal activity of mango (Mangifera indica L.) leaves against parthenium weed (Parthenium hysterophorus L.). The aqueous leaf extract at 15% concentration (on fresh weight basis) significantly reduced germination, shoot length and the shoot and root biomasses of parthenium seedlings. In a leaf residue incorporation pot trial, 2% residue incorporation treatment significantly suppressed the root and shoot biomasses of parthenium, while a 5% residue treatment completely stopped the growth of the weed. Five flavonoids, namely (-)-epicatechin-3-O-β-glucopyranoside (1), 5-hydroxy-3-(4-hydroxyphenyl)pyrano[3,2-g]chromene-4(8H)-one (2), 6-(p-hydroxybenzyl)taxifolin-7-O-β-D-glucoside (tricuspid) (3), quercetin-3-O-α-glucopyranosyl-(1 → 2)-β-D-glucopyranoside (4) and (-)-epicatechin(2-(3,4-dihydroxyphenyl)-3,4-dihydro-2H chromene-3,5,7-triol (5) were isolated from mango leaves. In a laboratory bioassay, 50 ppm solution of compounds 3 and 4 caused yellowing of the parthenium seedlings. A 250 ppm solution of compound 4 also significantly reduced germination and the root and shoot lengths of parthenium seedlings. This study concludes that compound 4 exhibits herbicidal activity against parthenium weed.     

A new 2-arylbenzofuran with antioxidant activity from the black colored rice (Oryza sativa L.) bran

From the black colored rice bran of Oryza sativa cv. Heugjinjubyeo, a new 2-arylbenzofuran, 2-(3,4-dihydroxyphenyl)-4,6-dihydroxybenzofuran-3-carboxylic acid methyl ester, oryzafuran (1), was isolated. Its structure has been elucidated on the basis of spectral data. This compound showed strong antioxidative activity in a 1,1-diphenyl-2-picrylhydrazyl free radical scavenging assay.     

Antioxidative phenylethanoid and phenolic glycosides from Picrorhiza scrophulariiflora

One new phenylenthanoid glycoside, scroside D (2), was isolated from the roots of Picrorhiza scrophulariiflora (Scrophulariaceae), together with nine known phenylethanoid and phenolic glycosides: 2-(3,4-dihydroxyphenyl)-ethyl-O-beta-D-glucopyranoside (1), 2-(3-hydroxy-4-methoxyphenyl)-ethyl-O-beta-D-glucopyranosyl (1-->3)-beta-D-glucopyranoside (3), scroside B (4), hemiphroside A (5), plantainoside D (6), scroside A (7), androsin (8), piceoside (9), and 6-O-feruloyl-beta-D-glucopyranoside (10). The structures of these compounds were elucidated using spectroscopic methods. The antioxidative activities of these isolated compounds were evaluated based on their scavenging effects on hydroxyl radicals and superoxide anion radicals, respectively. Compounds 1, 2, and 6 showed potent antioxidative effects as those of ascorbic acid and the structure-activity relationship is discussed.     

Facile Total Synthesis of Three Natural 1,7-Diaryl-4-hepten-3-ones

Linear 1,7-diarylheptanoids (Ar¹-C₇-Ar²) are a large group of interesting natural products isolated from plants belonging to Alinia,Curcuma, Zingiber, Alnua,Centridobium and Acer genera used as traditional medicines in some oriental countries¹. Pharmacological experiments exhibited that some of them had many physiological actions such as anti-inflammatory, antifungicial, antioxidative,antihepatotoxic activities and so on². Three natural compounds 1³, 2⁴ and 3⁵ (gingerone C) having 1,7-diaryl-4-hepten-3-one skeleton were isolated from the rhizomes of Alpinia offocinarum, the wood of Alnus japonica and the rhizomes of Zingiber officinale respectively. Their structures were elucidated as 1,7-diphenylhept-4-en-3-one(1), 1,7-bis(4-hydroxyphenyl)hept-4-en-3-one(2) and 1-(3-hydroxyl-4-methoxyphenyl)-7-(4-hydroxyphenyl)hept-4-en-3-one(3) by spectral method. Herein, we wish to report facile total synthesis of these three natural compounds. Their synthetic routes were shouwn in scheme.     

Five new phenylethanoid glycosides from the whole plants of Lamium purpureum L

Five new phenylethanoid glycosides, lamiusides A (1), B (2), C (3), D (4) and E (5), were isolated from the whole plants of Lamium purpureum L. (Labiatae) together with seven known compounds (6-12). On the basis of chemical and spectral analyses, the structures of the new compounds were elucidated to be 2-(3,4-dihydroxyphenyl)ethyl-O-beta-D-galactopyranosyl-(1-->2)-alpha-L-rhamnopyranosyl-(1-->3)-(4-O-trans-caffeoyl)-beta-D-glucopyranoside (1), 2-(3,4-dihydroxyphenyl)ethyl-O-beta-D-galactopyranosyl-(1-->2)-alpha-L-rhamnopyranosyl-(1-->3)-(4-O-trans-feruloyl)-beta-D-glucopyranoside (2), 2-(3,4-dihydroxyphenyl)ethyl-O-beta-D-galactopyranosyl-(1-->2)-alpha-L-rhamnopyranosyl-(1-->3)-(6-O-trans-caffeoyl)-beta-D-glucopyranoside (3), 2-(3,4-dihydroxyphenyl)-R,S-methoxy-ethyl-O-beta-D-galactopyranosyl-(1-->2)-alpha-L-rhamnopyranosyl-(1-->3)-(4-O-trans-caffeoyl)-beta-D-glucopyranoside (4) and 2-(3-hydroxy-4-methoxyphenyl)ethyl-O-alpha-L-rhamnopyranosyl-(1-->3)-beta-D-glucopyranosyl-(1-->6)-(4-O-cis-feruloyl)-beta-D-glucopyranoside (5). In addition, the radical-scavenging activities of compounds 1-4 on 1,1-diphenyl-2-picrylhydrazyl radical were examined.     

Synthesis of 1,7-Bis(4-hydroxyphenyl)-3-hydroxy-1,3-heptadien-5-one

l,7-Bis(4-hydroxyphenyl)-3-hydroxy-1,3-heptadien-5-oneIIwagfirstlyisolatedfromtheseedsofAIPiniablepharocalyxK.Schum.(Zingiberaceae)asanoveldiarylheptanoid.Meanwhile,l,7-his(4-hydroxyphenyl)-3-hydroxy-l,3,6-heptatTien-5-one2,aknowndiarylheptanoid,wasisolatedaswell.Therecentpublication'reportedthatIstronglyinhibitedtheaggregationofplateletinducedbycollagen,arachidonicacidandadenosinediphosphate.AdditionalresearchZprovedthat2couldactasaninhibitoroftheHIV-1integrase.Byourfindings,thesynthesi…     

New insights into the acid-promoted reaction of caffeic acid and its esters with nitrite: decarboxylation drives chain nitrosation pathways toward novel oxime derivatives and oxidation/fragmentation products thereof

In 0.05 M acetate buffer, pH 4, containing 1% methanol, caffeic acid (1a) (2 x 10(-3) M) reacted smoothly with nitrite (NO(2)(-)) (4 x 10(-3) M) to afford as main products the novel 2-hydroxy- and 2-methoxyaldoximes 7a,b, the 2-oxoaldoxime 9a, 3,4-dihydroxybenzoic acid, 3,4-dihydroxybenzaldehyde, and the known furoxan 3c and benzoxazinone 4b in smaller amounts. At lower 1a concentration (e.g., 1 x 10(-4) M), 7a was the main product, whereas with 0.1 M 1a and 0.5 M NO(2)(-) 3c and 9a were prevailing. At pH 2, 7a was still the most abundant product, together with 3,4-dihydroxybenzaldehyde and some 9a, whereas at pH 1 9a and 3,4-dihydroxybenzaldehyde were formed in higher yields. No evidence for ring nitration products, including the previously reported 4,5-dihydroxy-2-nitrobenzaldehyde, was obtained. At 2 x 10(-3) M concentration and at pH 4, caffeic acid methyl ester (1b) reacted with NO(2)(-) chiefly via ring nitration and/or dimerization to give 5a, the novel nitrated neolignan derivative 10, and the parent 6. Chlorogenic acid (1c) afforded only the ring nitrated derivative 5b. A unifying mechanism for the reaction of 1a and its esters with NO(2)(-) is proposed involving reversible formation of nitroso intermediates via chain nitrosation at the 2-position of the (E)-3-(3,4-dihydroxyphenyl)propenoic system. In the case of 1a, decarboxylation would drive the nitroso intermediates toward the formation of oximes 7a,b and 3c, reflecting nucleophilic addition of water, methanol, and NO(2)(-), and their oxidation or breakdown products, viz. 9a, 3,4-dihydroxybenzaldehyde, 3,4-dihydroxybenzoic acid, and the benzoxazinone 4b. In the case of esters 1b,c, to which decarboxylation is precluded, ring nitration or dimerization become the favored routes, triggered by preliminary oxidation at the catechol moiety.