Novel microbial transformation of resibufogenin by Fusarium solani

In this paper, microbial transformation of resibufogenin by Fusarium solani AS 3.1829 was investigated, and five transformed products were isolated and identified as 3-ketone-resibufogenin (2), 3-one-cyclic 3-(1,2-dimethyl-1,2-ethanediylacetal)-resibufogenin (3), 3-dimethoxyl-resibufogenin (4), 3-epi-resibufogenin (5), and 3-epi-15α-hydroxy-7βH-bufalin (6), respectively. Among them, 3, 4, and 6 are new compounds, and the rare double oxidization of C-3 was reported. In addition, the cytotoxicities of transformed products were also investigated.     

Biotransformation of resibufogenin by Actinomucor elegans

Resibufogenin (RB), a major bioactive bufadienolide, has the potential anticancer activity. In the present work, biotransformation of RB by Actinomucor elegans AS 3.2778 yielded five products, namely 3-oxo-resibufogenin (1), 3-epi-resibufogenin (2), 3-epi-12-oxo-hydroxylresibufogenin (3), 3α-acetoxy-15α-hydroxylbufalin (4), and 3-epi-12α-hydroxylresibufogenin (5), respectively. Among them, metabolites 3 and 4 are previously unreported. The chemical structures of metabolites 1–5 were fully elucidated on the basis of 2D NMR and HR-MS. The highly stereo- and regio-specific isomerization, hydroxylation, and esterification reactions were observed in the biotransformation process of RB by A. elegans. Their cytotoxicities against A549 and H1299 cells were evaluated.     

Microbial biotransformation of kurarinone by Cunninghamella echinulata AS 3.3400

In this paper, microbial transformation of kurarinone (1) by Cunninghamella echinulata AS 3.3400 was investigated and four transformed products were isolated and identified as 6″-hydroxykurarinone (2), 4″,5″,8″-trihydroxynorkurarinone (3), norkurarinone (4), and kurarinone-7-O-β-glucoside (5), respectively. Among them, 3 and 5 are new compounds, and the rare glycosylation in microbial transformation was observed. In addition, the cytotoxicities of transformed products (2–5) were also investigated.     

Diterpenoids from the freshwater green algae Rhizoclonium hieroglyphicum with antibacterial activity

Three new isopimarane diterpenes 7β-hydroxy-19α-methylmalonyloxy-isopimara-8(14),15-diene (1), 7β-hydroxy-14-oxo-isopimara-8(9),15-dien-19oic acid (2), and 7β-hydroxy-14-oxo-19α-methylmalonyloxy-isopimara-9(11),15-diene (3) in addition to the known compounds isopimaric acid (4), 7oxo-13-epi-pimara-14,15-dien-18oic acid (5), 7oxo-13-epi-pimara-8,15-dien-18oic acid (6), and 6β-hydroxyisopimaric acid (7) were isolated from the hexane extract of Rhizoclonium hieroglyphicum. The structures of compounds 1–7 were established by 1D and 2D NMR techniques. The isolated diterpenoids were screened for antimicrobial activity against gram-positive and gram-negative bacteria and yeast strains.     

Novel microbial transformation of resibufogenin by Fusarium solani

In this paper, microbial transformation of resibufogenin by Fusarium solani AS 3.1829 was investigated, and five transformed products were isolated and identified as 3-ketone-resibufogenin (2), 3-one-cyclic 3-(1,2-dimethyl-1,2-ethanediylacetal)-resibufogenin (3), 3-dimethoxyl-resibufogenin (4), 3-epi-resibufogenin (5), and 3-epi-15α-hydroxy-7βH-bufalin (6), respectively. Among them, 3, 4, and 6 are new compounds, and the rare double oxidization of C-3 was reported. In addition, the cytotoxicities of transformed products were also investigated.     

Antioxidant and α-amylase inhibitory activities of extract and isolates from Zygogynum pancheri subsp. arrhantum

One new sesquiterpenoid (5R^*,8R^*,9R^*,10R^*)-cinnamolide (8), and seven known compounds, 5-hydroxy-7-methoxyflavonone (1), 8-hydroxy-3-(4′-hydroxyphenyl)-6,7-(2″,2″-dimethylchromene)-tetralone (2), 8-hydroxy-3-(3′,4′-dihydroxyphenyl)-6,7-(2″,2″-dimethylchromene)-tetralone (3), 1β-E-O-p-methoxycinnamoyl-bemadienolide (4), 1β-O-(E-cinnamoyl)-6α-hydroxy-9-epi-polygodial (5), 1β-O-(E-cinnamoyl)-6α-hydroxypolygodial (6), and 1β-O-E-cinnamoylpolygodial (7) were isolated from the ethyl acetate extract of barks of Zygogynum pancheri subsp. arrhantum (Winteraceae). The structures of these molecules were assigned predominantly based on spectral data. The structure of compound 8 was confirmed by X-ray crystallographic analysis. Compounds 2 and 3 exhibited significant antioxidant activity, whereas compounds 1 and 4–7 showed significant α-amylase inhibitory activity.     

Microbial transformation of deoxyandrographolide by Fusarium graminearum AS 3.4598

Biotransformation of deoxyandrographolide (1) by Fusarium graminearum AS 3.4598 was investigated in this paper. And five transformed products of 1 by F. graminearum AS 3.4598 were obtained. Their chemical structures were characterized as 3-oxo-8α,17β-epoxy-14-deoxyandrographolide (2), 3-oxo-14-deoxyandrographolide (3), 3-oxo-17,19-dihydroxyl-8,13-ent-labdadien-15,16-olide (4), 1β-hydroxyl-14-deoxyandrographolide (5), and 7β-hydroxyl-14-deoxyandrographolide (6) by spectral methods including 2D NMR. Among them, products 2, 4, and 5 are new.     

Biotransformation of oleanolic acid by Alternaria longipes and Penicillium adametzi

Microbial transformation of oleanolic acid (1) was carried out. Six transformed products (2–7) from 1 by Alternaria longipes and three transformed products (8–10) from 1 by Penicillium adametzi were isolated. Their structures were elucidated as 2α,3α,19α-trihydroxy-ursolic acid-28-O-β-d-glucopyranoside (2), 2α,3β,19α-trihydroxy-ursolic acid-28-O-β-d-glucopyranoside (3), oleanolic acid 28-O-β-d-glucopyranosyl ester (4), oleanolic acid-3-O-β-d-glucopyranoside (5), 3-O-(β-d-glucopyranosyl)-oleanolic acid-28-O-β-d-glucopyranoside (6), 2α,3β,19a-trihydroxy-oleanolic acid-28-O-β-d-glucopyranoside (7), 21β-hydroxyl oleanolic acid-28-O-β-d-glucopyranoside (8), 21β-hydroxyl oleanolic acid (9), and 7α,21β-dihydroxyl oleanolic acid (10) based on the extensive NMR studies. Among them, 10 was a new compound and compounds 5 and 8–10 had stronger cytotoxic activities against Hela cell lines than the substrate. At the same time, it was reported for the first time in this paper that the skeletons of compounds 2 and 3 were changed from oleanane to uranane and seven glycosidation products were obtained by biotransformation.     

A tirucallane and two pairs of tetranortriterpene 23-epimers from the Thai mangrove Xylocarpus moluccensis

A new tirucallane, 3β-hydroxy-3-decarbonyl-24-epi-piscidinol A (1), and two new pairs of tetranortriterpene 23-epimers, named thaimoluccepimers A (2) and B (3), were isolated from the seeds of a Thai mangrove, Xylocarpus moluccensis. The structures of these compounds were elucidated by HRESIMS and NMR spectroscopic analysis.     

Chromone glycosides from Knoxia corymbosa

Four new chromone glycosides, corymbosins K₁-K₄ (3–6), together with two known compounds, noreugenin (1) and undulatoside A (2), were isolated from the whole plant of Knoxia corymbosa (Rubiaceae). The structures of the new compounds were established through extensive NMR or X-ray spectroscopic analysis as 7-O-β-d-allopyranosyl-5-hydroxy-2-methylchromone (corymbosin K₁, 3), 7-O-β-d-6-acetylglucopyranosyl-5-hydroxy-2-methylchromone (corymbosin K₂, 4), 7-O-[6-O-(4-O-trans-caffeoyl-β-d-allopyranosyl)]-β-d-glucopyranosyl-5-hydroxy-2-methylchromone (corymbosin K₃, 5) and 7-O-[6-O-(4-O-trans-feruloyl-β-d-allopyranosyl)]-β-d-glucopyranosyl-5-hydroxy-2- methylchromone (corymbosin K₄, 6). Compounds 2–5 were subjected to test their immunomodulatory activity in vitro.     

Aromatic glycosides from the flower buds of Lonicera japonica

Six new glycosides (1–6) have been isolated from the flower buds of Lonicera japonica. Their structures including the absolute configurations were determined by spectroscopic and chemical methods as ( ? )-2-hydroxy-5-methoxybenzoic acid 2-O-β-d-(6-O-benzoyl)-glucopyranoside (1), ( ? )-4-hydroxy-3,5-dimethoxybenzoic acid 4-O-β-d-(6-O-benzoyl)-glucopyranoside (2), ( ? )-(E)-3,5-dimethoxyphenylpropenoic acid 4-O-β-d-(6-O-benzoyl)-glucopyranoside (3), ( ? )-(7S,8R)-(4-hydroxyphenylglycerol 9-O-β-d-[6-O-(E)-4-hydroxy-3,5-dimethoxyphenylpropenoyl]-glucopyranoside (4), ( ? )-(7S,8R)-(4-hydroxy-3-methoxyphenylglycerol 9-O-β-d-[6-O-(E)-4-hydroxy-3,5-dimethoxyphenylpropenoyl]-glucopyranoside (5), and ( ? )-4-hydroxy-3-methoxyphenol β-d-{6-O-[4-O-(7S,8R)-(4-hydroxy-3-methoxyphenylglycerol-8-yl)-3-methoxybenzoyl]}-glucopyranoside (6), respectively.     

Microbial transformation of alantolactone by Mucor polymorphosporus

Two new transformed sesquiterpenes of alantolactone by Mucor polymorphosporus were obtained. They were characterized as 3β-hydroxy-11βH-eudesm-5-en-8β,12-olide (2) and 3β,11α-dihydroxy-eudesm-5-en-8β,12-olide (3), on the basis of spectral methods including 2D NMR. And product 3 was an unusual hydroxylation derivative of alantolactone at C-11.     

Microbial deglycosylation and ketonization of ginsenosides Rg1 and Rb1 by Fusarium oxysporum

Two major ginsenosides, ginsenoside-Rg₁ (1) and ginsenoside-Rb₁ (2), were transformed by the fungus Fusarium oxysporum f. sp. Lycopersici (Z-001). 1 was converted into five metabolites, ginsenoside-F₁ (3), 6α,12β-dihydroxydammar-3-one-20(S)-O-β-d-glucopyranoside (4), 3a-oxa-3a-homo-6α,12β-dihydroxydammar-3-one-20(S)-O-β-d-glucopyranoside (5), 20(S)-protopanaxatriol (6), and 3-oxo-20(S)-protopanaxatriol (7). 2 was converted into four metabolites, ginsenoside-Rd (8), ginsenoside-F₂ (9), compound K (10), and 12β-hydroxydammar-3-one-20(S)-O-β-d-glucopyranoside (11). The structures of these metabolites were determined by the analysis of extensive spectroscopic data. Among them, 4 and 5 were two new compounds. Deglycosylation and ketonization at C-3 were recognized as the characteristic reactions of this strain.     

Aromatic glycosides from the whole plants of Iris japonica

Phytochemical investigation on the whole plants of Iris japonica led to the isolation of four new aromatic glycosides. Their structures including the absolute configurations were determined by spectroscopic and chemical methods as (?)-4-hydroxy-3-methoxy acetophenone 4-O-β-d-{6-O-[4-O-(7R,8S)-(4-hydroxy-3-methoxyphenylglycerol-8-yl)-3-methoxybenzoyl]}-glucopyranoside (1), (?)-4-hydroxy-3-methoxy acetophenone 4-O-β-d-{6-O-[4-O-(7S,8R)-(4-hydroxy-3-methoxyphenylglycerol-8-yl)-3-methoxybenzoyl]}-glucopyranoside (2), (?)-4-hydroxy-3-methoxy acetophenone 4-O-β-d-{6-O-[4-O-(7R,8R)-(4-hydroxy-3-methoxyphenylglycerol-8-yl)-3-methoxybenzoyl]}-glucopyranoside (3), (?)-4-hydroxy-3-methoxy acetophenone 4-O-β-d-{6-O-[4-O-(7S,8S)-(4-hydroxy-3-methoxyphenylglycerol-8-yl)-3-methoxybenzoyl]}-glucopyranoside (4), respectively.     

Two novel sesquiterpenoids from Ainsliaea fragrans Champ.

A new sesquiterpene lactone, 3β-O-β-d-glucopyranosyl-8α-hydroxy-11α,13-dihydrozaluzanin C (1), and a novel trinorguaiane-type sesquiterpene, 4β,10α-dimethyl-1β,5α-bicycle[3,5,0]dec-6-en-4α,10β-diol (2), together with three known compounds, glucozaluzanin C (3), 11α,13-dihydrozaluzanin C (4), and 8α-hydroxy-11α,13-dihydrozaluzanin C (5), were isolated from the whole plant of Ainsliaea fragrans Champ. The structures of 1 and 2 were elucidated on the basis of detailed spectral analysis. Structures of the known compounds were identified by comparison of its spectral data with those values in the literature.     

Antibacterial sesquiterpene lactone glucoside from seed pods of Bauhinia retusa

From the seed pods of Bauhinia retusa, a new eudesmane sesquiterpene glucoside, 1-O-β-D-glucopyranosyl-9β,15-dihydroxy-5α,6βH-eudesma-3-ene-6α,12-olide (1), has been isolated together with three known compounds, 4′-hydroxy-7-methoxy flavane (2), β-sitosterol (3), and stigmasterol (4). The structures of isolated compounds were verified with the help of 1D, 2D NMR, and HR-ESI-MS spectroscopies. Compound 1 showed moderate antibacterial activity against Pseudomonas aeruginosa and Escherichia coli when a disc diffusion method is used.     

Microbial transformation of acetyl-11-keto-boswellic acid by Cunninghamella elegans

Microbial biotransformation of acetyl-11-keto-boswellic acid by Cunninghamella elegans AS 3.1207 was carried out, and totally four transformed products were isolated. On the basis of the extensive spectral data, their structures were characterized as 7β-hydroxy-11-keto-boswellic acid (1), 7β,30-dihydroxy-11-keto-boswellic acid (2), 7β,16α-dihydroxy-3-acetyl-11-keto-boswellic acid (3), and 7β,15α,21β-trihydroxy-3-acetyl-11-keto-boswellic acid (4), respectively. Among them, products 1 and 2 are the new compounds.     

Triterpene saponins of Maesa lanceolata stem wood

Phytochemical analysis of aqueous MeOH extract of Maesa lanceolata stem wood has led to the isolation of four new triterpene saponins characterized as 16α,21β-diacetoxy-22α-angeloyl-28-hydroxyolean-12-ene 3-O-[α-rhamnopyranosyl-(1″″ → 6?)-β-glucopyranosyl-(1? → 3′)][β-glucopyranosyl-(1″ → 2′)]-β-glucuronopyranoside (1), 16α-acetoxy-21β-hydroxy-22α-angeloyl-13β,28-oxydoolean-28α-ol 3-O-[α-rhamnopyranosyl-(1″″ → 6?)-β-glucopyranosyl-(1? → 4′)][β-glucopyranosyl-(1″ → 2′)]-α-arabinopyranoside (2), 16α-acetoxy-21β,22α-diangeloyl-13β,28-epoxyoleanane 3-O-[α-rhamnopyranosyl-(1″″ → 6?)-β-glucopyranosyl-(1? → 4′)][β-glucopyranosyl-(1″ → 2′)]-β-xylopyranoside (3), and 16α,22α-diacetoxy-13β,28-oxydoolean-28α-ol 3-O-[β-glucopyranosyl-(1″ → 2′)][β-glucopyranosyl-(1? → 3′)]-β-glucuronopyranoside (4), together with the known compounds β-acetylamyrin, physcion, emodin, chrysophanol, ursolic acid, 16α-hydroxy-12-oleanene 3-O-glucoside, β-amyrin, sitosterol 3-O-β-glucoside, stigmasterol, and 3β,28-dihydroxyolean-12-ene. Their structural elucidation was accomplished by homo- and heteronuclear 2D NMR technique as well as comparison with data from known compounds. The in vitro antibacterial activity of the aqueous MeOH extract was also investigated and zones of inhibition ranging from 32 ± 1.1 to 14 ± 0.2 mm were observed. Among the isolates, compound 1 was the most active with an minimum inhibitory concentration value of 25 μg/ml against Staphylococcus aureus.     

Note: Xanthone glycosides from Swertia franchetiana

A new xanthone glycoside (1) has been isolated from Swertia franchetiana together with five known xanthone glycosides. Their structures were elucidated as 7-O-[β-d-xylopyranosyl-(1→2)-β-d-xylopyranosyl]-1,7,8-trihydroxy-3-methoxyxanthone (1), 7-O-[α-l-rhamnopyranosyl-(1→2)-β-d-xylopyranosyl]-1,7,8-trihydroxy-3-methoxyxanthone (2), 8-O-β-d-glucopyranosyl-1,3,5,8-tetrahydroxyxanthone (3), 1-O-β-d-glucopyranosyl-1-hydroxy-3,7,8-trimethoxyxanthone (4), 1-O-[β-d-xylopyranosyl-(1→6)-β-d-glucopyranosyl]-1-hydroxy-2,3,5-trimethoxyxanthone (5) and 1-O-[β-d-xylopyranosyl-(1→6)-β-d-glucopyranosyl]-1-hydroxy-3,5-dimethoxyxanthone (6) on the basis of spectroscopic evidence.     

A New Larvicidal Lignan from Piper fimbriulatum.

Abstract

A new lignan, 3,4,5′-trimethoxy-3′,4′-methylenedioxy-7,9′:7′,9 diepoxylignan (1) (6-[4-(3,4-dimethoxy-phenyl)-tetrahydro-furo[3,4-c.]furan-1-yl]-4-methoxy-benzo[] dioxole) together with two known lignans, 7′-epi.-sesartemin (2) and diayangambin (3), and a known flavonoid, 5-hydroxy-7,4′-dimethoxyflavone (4), were isolated from the leaves of Piper fimbriulatum. C. DC. Their structures were assigned by a combination of one- and two-dimensional NMR techniques. 7′-epi.-Sesartemin (2) showed the highest larvicidal activity against Aedes aegypti. (LC₁₀₀ 17.6 µg/ml) and weak antiplasmodial (IC₅₀ 7.0 µg/ml) and antitrypanosomal (IC₅₀ 39.0 µg/ml) activities. None of the compounds was active against Leishmania mexicana..