Two new bioactive prenylated dihydroflavanoids from the medicinal plant Dolichos tenuicaulis (Baker) Craib

Two new prenylated dihydroflavanoids have been isolated from the medicinal plant of Dolichos tenuicaulis (Baker) Craib. Their structures were elucidated as (2S)-5,2',6'-trihydroxy-8-prenyl-6,7-(3-prenyl-2,2-dimethylpyrano)-3',4'-(2,2-dimethyl-1-keone-cyclohexadiene)-flavanone (1) and (2S)-5,2',6'-trihydroxy-8-prenyl-6,7-(3-prenyl-2,2-dimethyl-1-keone-cyclohexadiene)-flavanone (2) on the basis of spectroscopic analysis.     

Two new bioactive prenylated dihydroflavanoids from the medicinal plant Dolichos tenuicaulis (Baker) Craib

Two new prenylated dihydroflavanoids have been isolated from the medicinal plant of Dolichos tenuicaulis (Baker) Craib. Their structures were elucidated as (2S)-5,2′,6′-trihydroxy-8-prenyl-6,7-(3-prenyl-2,2-dimethylpyrano)-3′,4′-(2,2-dimethyl-1-keone-cyclohexadiene)-flavanone (1) and (2S)-5,2′,6′-trihydroxy-8-prenyl-6,7-(3-prenyl-2,2-dimethyl-1-keone-cyclohexadiene)-flavanone (2) on the basis of spectroscopic analysis.     

Erysenegalenseins H and I: Two New Isoflavones from Erythrina senegalensis1

In addition to the known Compounds senegalensin, lupinifolin, erythrisenegalone, and auriculatin, two new isoflavones named erysenegalensein H and erysenegalensein I were isolated from the dichloromethane extract of the stem bark of ERYTHRINA SENEGALENSIS DC. On the basis of spectroscopic methods their structures were elucidated as 5,2',4'-trihydroxy-8-(gamma,gamma-dimethylallyl)-2'-hydroxyisopropyldihydrofurano[4',5':6,7]-isoflavone and 5,2',4'-trihydroxy-8-(gamma,gamma-dimethylallyl)-3'-hydroxy-2',2'-dimethyldihydropyrano [5',6':6,7]-isoflavone, respectively.     

New abietane diterpenoids from the mangrove Avicennia marina

Phytochemical investigations of the twigs of Avicennia marina yielded three new abietane diterpenoids 11-hydroxy-8,11,13-abietatriene 12- O-beta-xylopyranoside ( 1), and a pair of inseparable epimers 6 Halpha-11,12,16-trihydroxy-6,7-secoabieta-8,11,13-triene-6,7-dial 11,6-hemiacetal ( 2) and 6 Hbeta-11,12,16-trihydroxy-6,7-secoabieta-8,11,13-triene-6,7-dial 11,6-hemiacetal ( 3), as well as the new lignan (7' S,8' R)-4,4',9'-trihydroxy-3,3',5,5'-tetramethoxy-7,8-dehydro-9-al-2,7'-cyclolignan ( 5), together with 6,11,12,16-tetrahydroxy-5,8,11,13-abitetetraen-7-one ( 4), lyoniresinol ( 6), lyoniresinol 9'- O-beta- D-glucopyranoside ( 7), and diacetylmartynoside ( 8). Structure elucidation of the new compounds was accomplished by analysis of their spectroscopic data. Compounds 2 - 4 showed moderate cytotoxic and antimicrobial activities.     

Dihydrochalcones and benzoic acid derivatives from Piper dennisii

Two new dihydrochalcones (1, 2), as well as eight known compounds, piperaduncin C (3), 2',6'-dihydroxy-4'-methoxydihydrochalcone (4), 4,2',6'-trihydroxy-4'-methoxydihydrochalcone (5), 4-hydroxy-3,5-bis(3-methyl-2-butenyl)-benzoic acid (6), 3,5-bis(3-methyl-2-butenyl)-4-methoxybenzoic acid (7), 4-hydroxy-3-(3-methyl-2-butenoyl)-5-(3-methyl-2-butenyl)-benzoic acid (8), 2,2-dimethyl-8-(3-methyl-2-butenyl)-2H-1-chromene-6-carboxylic acid (9), and 3-(3',7'-dimethyl-2',6'-octadienyl)-4-methoxybenzoic acid (10) were isolated from the leaves of Piper dennisii Trelease (Piperaceae), using a bioassay-guided fractionation to determine their antileishmanial potential. Among them, compound 10 exhibited the best antileishmanial activity (IC50 = 20.8 μM) against axenic amastigote forms of Leishmania amazonensis, with low cytotoxicity on murine macrophages. In the intracellular macrophage-infected model, compound 10 proved to be more active (IC50 = 4.2 μM). The chemical structures of compounds 1-10 were established based on the analysis of the spectroscopic data.     

New dihydrochalcones and anti-platelet aggregation constituents from the leaves of Muntingia calabura

Two new dihydrochalcones, 2,3-dihydroxy-4,3',4',5'-tetramethoxydihydrochalcone (1) and 4,2',4'-trihydroxy-3'-methoxydihydrochalcone (2), and a new flavanone, (2R,3R)-(-)-3,5-dihydroxy-6,7-dimethoxyflavanone (3), together with nineteen known compounds have been isolated from the leaves of Muntingia calabura. The structures of three new compounds were determined through spectral analyses including extensive 2D-NMR data. Among the isolates, 2,3-dihydroxy-4,3',4',5'-tetramethoxydihydrochalcone, 5,7-dihydroxy-3-methoxyflavone, 5,7-dihydroxy-6-methoxyflavone, 5,4'-dihydroxy-3,7-dimethoxyflavone, (2S)-7,8,3',4',5'-pentamethoxyflavan, (2S)-5'-hydroxy-7,8,3',4'-tetramethoxyflavan, and methyl gallate exhibited significant anti-platelet aggregation activity in vitro.     

In Vitro Free Radical and ONOO- Scavengers from Sophora flavescens

Activity-guided fractionation of the CH2Cl2-soluble fraction of the roots of Sophora flavescens furnished five 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavengers: trans-hexadecyl ferulic acid (1), cis-octadecyl ferulic acid (2), trans-hexadecyl sinapic acid (3), (-)-4-hydroxy-3-methoxy-(6aR,11aR)-8,9-methylenedioxypterocarpan (4) and desmethylanhydroicaritin (8), along with nine known inactive compounds: (-)-maackiain (5), xanthohumol (6), formononetin (7), (2S)-2'-methoxykurarinone (9), (2S)-3beta,7,4'-trihydroxy-5-methoxy-8-(gamma,gamma-dimethylallyl)-flavanone (10), (2S)-7,4'-dihydroxy-5-methoxy-8-(gamma,gamma-dimethylallyl)-flavanone (11), umbelliferone (12), kuraridin (13), and trifolirhizin (14). Compounds 1-4 and 8 exhibited DPPH free radical scavenging effects at IC50 values of 33.01 +/- 0.20, 57.06 +/- 0.16, 39.84 +/- 0.36, 35.83 +/- 0.47, and 18.11 +/- 0.04 microM, respectively. L-Ascorbic acid, when used as a positive control, exhibited an IC50 value of 7.39 +/- 0.01 microM. Compounds 1-4 and 8 also appeared to exert significant scavenging effects on authentic ONOO-, with IC50 values of 5.76 +/- 1.19, 15.06 +/- 1.64, 8.17 +/- 4.97, 1.95 +/- 0.29, and 4.06 +/- 2.41 microM, respectively. Penicillamine (IC50 = 2.36 +/- 0.79 microM) was used as a positive control. In addition, compounds 2, 4, 6, 8, and 10 were isolated from this plant for the first time.     

Inhibition of protein tyrosine phosphatase 1B by prenylated isoflavonoids isolated from the stem bark of Erythrina addisoniae

It has been suggested that protein tyrosine phosphatase 1B (PTP1B) inhibitors might be a therapeutic target for the treatment of type 2 diabetes and obesity. A bioassay-guided phytochemical study of the EtOAc extract of the stem bark of Erythrina addisoniae (Leguminosae) resulted in the identification of a new PTP1B inhibitory compound, 5,2',4'-trihydroxy-6-(gamma,gamma-dimethylallyl)-2',2'-dimethyldihydropyrano[5',6']isoflavanone ( 6), along with five known prenylated isoflavonoids, orientanol E ( 1), senegalensin ( 2), warangalone ( 3), warangalone 4'-methyl ether ( 4) and 2,3-dihydroauriculatin ( 5). Compounds 1, 5 and 6 inhibited PTP1B with IC (50) values ranging from 2.6 +/- 0.5 to 10.1 +/- 0.3 microM. Our results indicate that hydroxylation at both 2'- and 4'-positions in the B-ring and cyclization between a hydroxy group at C-7 and one of the prenyl groups at C-6 or C-8 in the A-ring may be important for activity. Thus, compounds 5 and 6 could be a new class of natural PTP1B inhibitors.     

Lignans from the flower buds of Magnolia liliflora Desr

Six new lignans, 1- 6, along with six known compounds were obtained from the flower buds of Magnolia liliflora Desr. The new lignans were elucidated as (1 S*,2 R*,5 S*,6 S*)-2-(3,5-dimethoxyphenyl)-6-(3,4-methylenedioxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (1), (1 R*,2 R*,5 R*,6 S*)-2-(3,5-dimethoxyphenyl)-6-(3,4-methylenedioxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (2), (1 R*,?2 R*,5 R*,6 S*)-2,6-bis (3,5-dimethoxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (3), (1 R*,2 S*,5 R*,6 R*)-2-(3,4-methylenedioxyphenyl)-6-(3,5-dimethoxyphenyl)-3,7-dioxabicyclo[3.3.0]octane ( 4), (7' S*,8 R*,8' R*)-3,5'-dimethoxy-3',4,9'-trihydroxy-7',9-epoxy-8,8'-lignan (5), and (7' R*,8' S*)-3,3',4,5'-tetramethoxy-7-en-7',9-epoxy-8,8'-lignan (6), by the analysis of 1D and 2D-NMR as well as HRESIMS data. The capacity of compound 1 to protect against damages to the DNA of rat lymphocyte cells induced by UV irradiation was assessed by the comet assay. It showed stronger antigenotoxicity than ascorbic acid from 6×10(-3)?mmol·L(-1) to 6×10(-6)?mmol·L(-1).     

A new flavone 2'-glucoside from Andrographis alata

A new flavone glucoside, 5,2',6'-trihydroxy-7-methoxyflavone 2'-O-β-D-glucopyranoside has been isolated from the whole plant of Andrographis alata. The structure was elucidated on the basis of spectral and chemical evidence.     

New coumarins from Pterocaulon polystachyum

Aerial parts of Pterocaulon polystachyum from Chaco province, Argentina, afforded the known coumarins ayapin, isoscopoletin, prenyletin, prenyletin methyl ether, virgatenol, obtusinin, 5-methoxy-6,7-methylenedioxycoumarin, 5-(3,3-dimethylallyloxy)-6,7-methylenedioxycoumarin, 5-(2',3'-dihydroxy-3-methylbutanoxy)-6,7-methylenedioxycoumarin, haplopinol methyl ether, 6-(1,1-dimethyl-2-propenyl)-7-hydroxycoumarin and demethylnieshoutin; the last two are new as natural products while the five new coumarins from the collection were isovirgatenol, 3'-deoxyobtusinin, 6-methoxy-7-(2'-hydroxyethoxy)-coumarin, 5-(2'-hydroxyethoxy)-6,7-methylenedioxycoumarin and a substance tentatively identified as 5-hydroxy-6,7-methylenedioxy-8-(3,3-dimethylallyl)-coumarin.     

Isolation and characterization of new Cannabis constituents from a high potency variety

Phytochemical investigation of a high potency variety of Cannabis sativa L. resulted in the isolation of six new metabolites, (+/-)-6,7-trans-epoxycannabigerolic acid ( 2), (+/-)-6,7- CIS-epoxycannabigerolic acid ( 3), (+/-)-6,7- CIS-epoxycannabigerol ( 4), (+/-)-6,7-trans-epoxycannabigerol ( 5), 5'-methyl-4-pentylbiphenyl-2,2',6-triol ( 7), and 7-methoxycannabispirone ( 8), along with seven known compounds namely, cannabigerolic acid ( 1), 5'-methoxycannabigerolic acid ( 6), cannabispirone ( 9), beta-cannabispiranol ( 10), dehydrocannabifuran ( 11), cannflavin B ( 12) and cannabigerol ( 13). The antimicrobial as well as the antileishmanial activities were investigated.     

Methylated Flavones from Teucrium polium

The following four methylated flavones were obtained from the leaves of TEUCRIUM POLIUM L. (Labiatae). 4', 5-dihydroxy-6,7-dimethoxyflavone (cirsimaritin); 3', 5 dihydroxy-4',6,7-trimethoxyflavone (eupatorin); 5-hydroxy-4',7-dimethoxyflavone (apigenin-4', 7-dimethylether); 4', 5, 3'-trihydroxy-6,7-dimethoxyflavone (cirsiliol). One of these (4', 5-dihydroxy- 6,7-dimethoxyflavone) has been already reported in the same plant by Brieskorn and Biechele (1).     

浅裂鳞毛蕨中的一个新二氢黄酮

目的研究浅裂鳞毛蕨(Dryopteris sublaeta Ching et Hsu)的化学成分。方法利用硅胶柱色谱进行分离纯化，根据化合物的理化性质和光谱数据鉴定结构。结果从浅裂鳞毛蕨中分离并鉴定了4个化合物，分别为：2(S)-5,7,3′-三羟基-6,8-二甲基-5′-甲氧基-二氢黄酮(1)，荚果蕨素(5,7-二羟基-6,8-二甲基-4′-甲氧基-二氢黄酮，matteucinol)(2)，去甲氧基荚果蕨素(5,7-二羟基-6,8-二甲基-二氢黄酮，desmethoxymatteucinol)(3)和2′-羟基去甲氧基荚果蕨素(5,7,2′-三羟基-6,8-二甲基-二氢黄酮,2′-hydroxy-desmethoxymatteucinol)(4)。结论化合物1为新化合物，其余化合物均为首次从该属植物中分离得到。     

Antitumor activity of flavones isolated from Artemisia argyi

The flavones 5,6-dihydroxy-7,3',4'-trimethoxyflavone ( 1), 5,6,4'-trihydroxy-7,3'-dimethoxyflavone ( 2), 5-hydroxy-3',4',6,7-tetramethoxyflavone, 5,7,3'-trihydroxy-6,4',5'-trimethoxyflavone, ladanein, and hispidulin were isolated from the methanolic extracts of the aerial parts of Artemisia argyi and structures of the compounds were elucidated on the basis of their spectral data. These flavones inhibited farnesyl protein transferase with IC 50 values of 25 - 200 microg/mL. Compound 2 inhibited proliferation of a couple of tumor cell lines and also inhibited neovascularization in a chick chorioallantoic membrane assay. Without loss of body weight of nude mice, compounds 1 and 2 inhibited growth of a colon tumor (SW620) by 44.6 % and 14.6 %, respectively.     

Synthesis and complement inhibitory activity of B/C/D-ring analogues of the fungal metabolite 6,7-diformyl-3',4',4a',5',6',7',8',8a'-octahydro-4,6',7'-trihydroxy- 2',5',5',8a'-tetramethylspiro[1'(2'H)-naphthalene-2(3H)-benzofuran

This paper reports the synthesis and the bioassay of 4-methoxy- and 4-hydroxyspiro[benzofuran-2(3H)-cyclohexane] partial analogues (5) of the complement inhibitory sesquiterpene fungal metabolite 6,7-diformyl-3',4',4a',5',6',7',8',8a'-octahydro-4,6',7'-trihydroxy-2',5',5',8a'-tetramethylspiro[1'(2'H)-naphthalene-2(3H)-benzofuran] (1a, K-76) and its silver oxide oxidized product (1b, K-76COOH). The described target compounds represent spirobenzofuran B/C/D-ring analogues lacking the A-ring component of the prototype structure. The target compounds were evaluated by the inhibition of total hemolytic complement activity in human serum. It was observed that the structurally simplified analogue 4-methoxyspiro[benzofuran-2(3H)-cyclohexane]-6-carboxylic acid (5a) exhibited an IC(50) = 0.53 mM similar to the IC(50) = 0.57 mM that was observed for the natural product derivative 1b. Exhibiting an IC(50) = 0.16 mM, the three-ringed partial structure 6-carboxy-7-formyl-4-methoxyspiro[benzofuran-2(3H)-cyclohexane] (5k)was found to be the most potent target compound. Like the natural product, 5k appears to inhibit primarily at the C5 activation step and inhibits both the classical and alternative human complement pathways. Several other analogues inhibited complement activation in vitro at concentrations similar to those required for inhibition by the natural product 1b.     

Phytochemical investigation of Anaphalis lactea

Four new compounds, 2',6'-dihydroxy-3'-(2-hydroxy-3-methyl-3-butenyl)-4'-methoxychalcone ( 1), 4,6-dihydroxy-7-isobutyryl-5-prenyl-2(3 H)-benzofuranone ( 4), 7- O-(beta- D-glucopyranosyloxy)-5-hydroxy-1(3 H)-isobenzofuranone ( 6) and (2 R,3 S)-3-methyl-2-(5-oxo-2-isopropenylhexyl)-cyclopentanone ( 7), along with thirteen known compounds were isolated from the whole plant of Anaphalis lactea. Their structures were established based on spectroscopic methods including IR, UV, MS, CD, 1 D NMR and 2 D NMR techniques. Compounds 2, 4 - 6 and 8 - 16 were tested for free-radical scavenging properties in the DPPH assays.     

鸡血藤化学成分的分离与结构鉴定

目的对中药鸡血藤(Spatholobus suberectus Dunn)中化学成分进行分离及结构鉴定。方法采用正相硅胶、反相ODS、Sephadex LH-20等柱色谱及高效液相色谱等手段进行分离纯化,并通过理化性质与波谱分析方法鉴定了化合物的结构。结果从鸡血藤体积分数为95%的乙醇提取物中分离鉴定了9个单体成分,分别为blumenol A(1)、(6S,7E,9R)-roseoside(2)、(6S,7E,9R)-6,9-dihydroxy-4,7-megastigman-3-one-9-O-[α-L-arabinopyranosyl-(1→6)-(β-D-glucopyranoside](3)、7S,8R-erythro-4,9,9'-trihydroxy-3,3'-dimethoxy-8-O-4'-neolignan-7-O-β-D-glucopyranoside(4)、(7S,8R)-dihydrodehydrodiconiferyl alcohol-4-O-(β-D-glucopyranoside(5)、(7S,8R)-3,3',5-trimethoxy-4',7-epoxy-8,5'-neolignan-4,9,9'-triol(6)、次黄苷(hypoxanthine-9-β-D-ribofuranoside,7)、烟酸(nicotinic acid,8)和丁二酸(amber acid,9)。结论其中2-8均为首次从密花豆属中分离得到的化合物。     

Inhibitory activities of prenylated flavonoids from Sophora flavescens against aldose reductase and generation of advanced glycation endproducts

Important targets for the prevention and treatment of diabetic complications include aldose reductase (AR) inhibitors (ARIs) and inhibitors of advanced glycation endproduct (AGE) formation. Here we evaluate the inhibitory activities of prenylated flavonoids isolated from Sophora flavescens, a traditional herbal medicine, on rat lens AR (RLAR), human recombinant AR (HRAR) and AGE formation. Among the tested compounds, two prenylated chalcones--desmethylanhydroicaritin (1) and 8-lavandulylkaempferol (2)--along with five prenylated flavanones--kurarinol (8), kurarinone (9), (2S)-2'-methoxykurarinone (10), (2S)-3beta,7,4'-trihydroxy-5-methoxy-8-(gamma,gamma-dimethylally)-flavanone (11), and kushenol E (13) were potent inhibitors of RLAR, with IC50 values of 0.95, 3.80, 2.13, 2.99, 3.77, 3.63 and 7.74 microM, respectively, compared with quercetin (IC50 7.73 microM). In the HRAR assay, most of the prenylated flavonoids tested showed marked inhibitory activity compared with quercetin (IC50 2.54 microM). In particular, all tested prenylated flavonols, such as desmethylanhydroicaritin (1, IC50 0.45 microM), 8-lavandulylkaempferol (2, IC50 0.79 microM) and kushenol C (3, IC50 0.85 microM), as well as a prenylated chalcone, kuraridin (5, IC50 0.27 microM), and a prenylated flavanone, (2S)-7,4'-dihydroxy-5-methoxy-8-(gamma,gamma-dimethylally)-flavanone (12, IC50 0.37 microM), showed significant inhibitory activities compared with the potent AR inhibitor epalrestat (IC50 0.28 microM). Interestingly, prenylated flavonoids 1 (IC50 104.3 microg mL(-1)), 2 (IC50 132.1 microg mL(-1)), 3 (IC50 84.6 microg mL(-1)) and 11 (IC50 261.0 microg mL(-1)), which harbour a 3-hydroxyl group, also possessed good inhibitory activity toward AGE formation compared with the positive control aminoguanidine (IC50 115.7 microg mL(-1)). Thus, S. flavescens and its prenylated flavonoids inhibit the processes that underlie diabetic complications and related diseases and may therefore have therapeutic benefit.     

RP-HPLC法测定细叶鸢尾中二氢黄酮的含量

目的：建立RP-HPLC法,测定细叶鸢尾中一种具有抗老年痴呆症活性的二氢黄酮：5,2＇,3＇-三羟基-6,7-亚甲二氧基二氢黄酮。方法采用Agilent 1260HC－C18（4．6 mm ×250 mm,5μm）色谱柱,流动相为甲醇—1％冰醋酸梯度洗脱,流速为1 mL ·min－1,检测波长为295 nm,柱温为25℃。结果该二氢黄酮在37．6～188 mg·L －1浓度范围内线性关系良好,相关系数为0．9994;回收率为101．26％（RSD＝1．17％）。测得该活性化合物在细叶鸢尾中的含量非常高,6批药材中的含量为57．70～59．35 mg·g－1。结论该检测方法准确,适用于细叶鸢尾中5,2＇,3＇-三羟基-6,7-亚甲二氧基二氢黄酮的测定。