Lignans and Triterpenes from the Bark of Durio carinatus and Durio oxleyanus

Abstract

Investigation of chemical constituents from the bark of Durio carinatus has led to the isolation of three lignans, boehmenan X (1), threo-carolignan X (2), and erythro-carolignan X (3), together with the three known lignans boehmenan, threo-carolignan E, and erythro-carolignan E. The bark of D. oxleyanus yielded two new lignan ethers, threo-carolignan Y (4) and erythro-carolignan Y (5), together with compounds 1, 3, and boehmenan. J-Based configurational analysis and NOE measurements were used to explore conformational issues for the lignan diastereomers, while CD measurements supported an 8'S configuration for the various lignans. The triterpenes 3β-O-cis-caffeoylbetulinic acid and 3β-O-trans-caffeoylbetulinic acid were also characterized from D. carinatus.

Cytotoxic Phenylpropanoids and a New Triterpene, Turformosinic Acid, from Turpinia formosana Nakai

“…Compound 1 is thus closely related to (−)-(7′ S ,8′ S )- threo -carolignan X ( 3 ), except for the position of feruloyl and 4-hydroxycinnamoyl units and the stereochemistry of the 7,8,9-propantriol moiety [ 13 ]. Inspection of the HMBC spectrum of 1 revealed cross peaks between the following proton and carbon signals: H-8 (δ H 4.60) with C-4' (phenoxy ring δ C 147.2), H-9 (δ H 4.45) with C-9'' (δ C 169.3, carbonyl carbon in ferulic acid), and H-9' (δ H 4.09) with C-9''' (δ C 168.9, cinnamic acid carbonyl), which determined the planar structure of 1 to be 7-(4-hydroxy-3-methoxyphenyl)-9-(4-hydroxy-3-methoxy-cinnamoyloxy)-8{4'-[9'-(4-hydroxycinnamoyloxy)-7'-propenyl]-3'-methoxyphenoxy}-1-propanol.…”

“…As to compound 1 , the H-7 proton resonance had a small coupling constant ( J H7-H8 = 3.2 Hz), indicating the presence of the e rythro diastereomer. Comparison of the 13 C spectra (CDCl 3 ) of 1 and 3 , compound 1 has higher field C-7 signals (δ C 72.3 in 1 ; δ C 74.4 in 3 ), C-8 (δ C 84.2 in 1 ; δ C 86.2 in 3 ), and C-9 (δ C 62.8 in 1 ; δ C 63.1 in 3 ) revealing the erythro form of 1 , rather than the threo form of 3 [ 13 ]. Therefore, erythro - 1 have the (7 R ,8 S ) configuration and threo - 3 would be 7S,8S configuration.…”

“…The 16 additional isolated compounds were identified as (−)-(7′ S ,8′ S )- threo -carolignan X ( 3 ) [ 13 ], 2α,3β,19β-23-tetrahydroxyolean-12-en-28-oic acid ( 4 ) [ 17 ], methoxyhydroquinone-4-β- D -glucopyranoside ( 5 ) [ 19 ], methoxyhydroquinone-1-β- D -glucopyranoside ( 6 ) [ 20 ], 3,5-dimethoxybenzyl alcohol 4- O -β- D -glucopyranoside ( 7 ) [ 21 ], 4-(3-hydroxy-1-propenyl)-2,6-dimethoxyphenyl β- D -glucopyranoside ( 8 ) [ 22 ], d- threo -guaiacylglycerol- O -β- D -glucopyranoside ( 9 ) [ 23 ], (7 S ,8 R )-syringoylglycerol-7- O -β- D -glucopyranoside ( 10 ) [ 24 ], 6- O -( p -hydroxybenzoyl)- D -glucose ( 11 ) [ 25 ], d-glucose-6(4-hydroxy-3-methoxybenzoate) ( 12 ) [ 26 ], dihydrophaseic acid 4'- O -β- D -glucopyranoside ( 13 ) [ 27 ], 3'- O -methyl ellagic acid 4- O -β- D -xylopyranoside ( 14 ) [ 28 ], 3'- O -methyl ellagic acid 4- O -α- L -rhamnopyranoside ( 15 ) [ 29 ], uridine ( 16 ) [ 30 ], adenosine ( 17 ) [ 31 ], and β-sitosteryl glucoside ( 18 ) [ 32 ], respectively, by comparison with the spectroscopic data reported in the literature for these compounds.…”

“…Selected isolated compounds ( 1 – 6 and 9 – 16 ) were also evaluated for cytotoxic and antioxidative activities. (−)-(7′ S ,8′ S )- threo -Carolignan X ( 3 ) [ 13 ] showed strong cytotoxicity against Hep2 cells. In addition, this is the first report on the cytotoxic activities of (−)-(7′ S ,8′ S )- threo -carolignan X ( 3 ) and induced apoptosis in Hep2 cells is also described.…”

Phenolics from Durian Exert Pronounced NO Inhibitory and Antioxidant Activities

“…However, durian fruit is rich in nutrients such as carbohydrates and protein and also contains sufficient vitamins B and C. In addition to eaten raw, its attractive flesh is frozen or dried for a popular snack. Previous chemical studies on Durio have resulted in the identification of triterpenoids, phenolics, lignans, coumarins, flavonoids, sulfur-containing compounds, and some uncommon esters. − In spite of the abundant secondary metabolites in durian, little research has been concerned with the bioactive constituent in durian, especially in its peel that has currently been treated as agricultural waste.…”