Cis-GPRA synthesis by enzymatic removal of a p-methoxybenzyl protecting group from p-methoxybenzyl-7-phenylacetylamino-3-propenyl-3-cephem-4-carboxylate

Abstract

Twelve typical commercial hydrolases and crude cell extract of Bacillus subtilis ATCC6633 were tested for their activity to synthesize cis-7-phenylacetamido-3-propenyl-cephalosporanic acid (cis-GPRA) by enzymatic removal of a p-methoxybenzyl protecting group from p-methoxybenzyl-7-phenylacetylamino-3-propenyl-3-cephem-4-carboxylate (GPRE) in aqueous– organic solvents. No activity was detected for 12 commercial enzymes. However, the crude cell extract showed significant activity for removing the p-methoxybenzyl protecting group from GPRE to produce cis-GPRA. The yield of cis-GPRA reached 73% with the initial reaction rate of 10.2 μM h^?1 under the optimized reaction conditions.     

Synthesis of cefprozil using penicillin G acylase in recyclable aqueous two-phase systems

Cefprozil is an important semi-synthetic cephalosporin antibiotic. In this study, immobilized penicillin G acylase (PGA) is used to catalyze the acylation of 7- amino-3-(1-propenyl)-4-cephalosporanic acid (7-APRA) and 4-hydroxyphenylglycine methyl ester (HPGME) and a recyclable thermo-pH responsive P_NB/P_ADB aqueous twophase system (ATPS) is used to synthesize cefprozil. In this system, the partition coefficient of cefprozil was 2.24 with 60 mmol/L (NH₄)₂SO₄. In addition, the optimal enzymatic reaction conditions were found to be pH 6.5, 20°C, 78 u/mL immobilized PGA, 30 mmol/L 7-APRA and 90 mmol/L HPGME. In the P_NB/P_ADB ATPS, the maximal yield of cefprozil was 75.81% with 60 mmol/L (NH₄)₂SO₄ and in the single aqueous system the yield was 56.02%. The yields are thought to improve because there is a reduction in product inhibition.     

Changing the specificity of α-amino acid ester hydrolase toward para-hydroxyl cephalosporins synthesis by site-directed saturation mutagenesis

α-Amino acid ester hydrolases (AEHs) catalyze the synthesis of β-lactam antibiotics containing an α-amino group with decreased activity toward antibiotics with a p-hydroxyl group. The AEH gene from Xanthomonas rubrillineans was cloned and expressed in Escherichia coli. Based on the crystal structure of the AEH and cefprozil complex, 13 residues not directly involved in substrate recognition were mutated individually. The resulting ~1,300 mutants were screened for activity using cefprozil as a model product based on spectrophotometric assay in a 96-well format. Mutants with improved cefprozil synthetic activity revealed the particular importance of positions 87, 131 and 175 for specificity. The mutant V131S with the highest initial rates of synthesis toward three p-hydroxyl cephalosporins showed 23?%, 17?% and 64?% increase in maximum product accumulation of cefadroxil, cefprozil and cefatrizine, respectively.     

Ionization constants and solubility of compounds involved in enzymatic synthesis of aminopenicillins and aminocephalosporins

The article deals with experimental determination of ionization constants and solubility for the compounds (target products, initial β-lactams, acylating agents and by-products) involved in enzymatic synthesis of some therapeutically used aminopenicillins and aminocephalosporins, namely ampicillin, amoxicillin, cephalexin, cephadroxil, cephaloglycin, cefaclor, cefprozil, cefatrizine. Methodology of investigations and the evaluation of experimental data for the determination of ionization constants and solubility of the different type electrolytes are presented. Applications of the methods based on acid–base potentiometric titration and on determination of solubility–pH dependence of assayed substances are discussed. The original data on ionization constants and solubility of amoxicillin, cefprozil, cefatrizine, cephadroxil and initial β-lactams for production of cefaclor, cefprozil and cefatrizine, as well as solubility of by-product d-(−)-p-hydroxyphenylglycine are presented. Experimentally determined parameters and constants available in the literature for all abovementioned aminopenicillins and aminocephalosporins are collected. These data might be used for choice of the conditions of both processes: the enzymatic synthesis and the isolation of the product from reaction mixture.     

The Bla2 β-lactamase from the live-vaccine strain of Francisella tularensis encodes a functional protein that is only active against penicillin-class β-lactam antibiotics

Francisella tularensis ssp. tularensis is a category A select agent and the causal organism for the zoonotic disease tularemia. The vast majority of F. tularensis isolates are β-lactamase-positive. β-lactamase production is widely believed to be responsible for the inefficacy of β-lactams in the treatment of tularemia. In this study, we report the cloning and characterization of the two chromosomally encoded F. tularensis ssp. holarctica live-vaccine strain (LVS) β-lactamases. The two LVS β-lactamases were homologous to F. tularensis Schu S4 open reading frames FTT0681c and FTT0611c and have been named bla1 _LVS and bla2 _LVS , respectively. Recombinant expression in Escherichia coli suggested that bla1 _LVS did not encode a functional β-lactamase, whereas bla2 _LVS encoded a functional β-lactamase that hydrolyzed penicillins but was inactive against third-generation cephalosporins, including cefprozil. As both LVS and Schu S4 were susceptible to cefprozil, we developed three new shuttle vectors based on selection for the production of the Bla_shv-2 extended-spectrum β-lactamase with cefprozil. The resulting shuttle vectors were suitable for recombinant gene expression and complementation studies in LVS and Schu S4.     

The Enzymic and Chemical Synthesis of Ursodeoxycholic and Chenodeoxycholic Acid from Cholic Acid

Three approaches to the synthesis of ursodeoxycholic acid (UDC) from cholic acid have been investigated: (i) oxidation of cholic acid to 3α,7α-dihydroxy-12 keto-5β-cholanoic acid (12K-CDC) with Clostridium group P 12α-hydroxysteroid dehydrogenase (HSDH), isomerization of 12K-CDC to 3α, 7β-dihydroxy-12 keto-5β-cholanoic acid (12K-UDC) with Clostridium absonum 7α- and 7β-HSDH and reduction of 12K-UDC by Wolff-Kishner to UDC; (ii) isomerization of cholic acid to ursocholic acid (UC) by C. absonum 7α- and 7β-HSDH, oxidation of UC to 12K-UDC with Clostridium group P 12α-HSDH and Wolff-Kishner reduction of 12K-UDC to UDC; (iii) oxidation of cholic acid to 12K-CDC by Clostridium group P 12α-HSDH, Wolff-Kishner reduction of 12K-CDC to chenodeoxycholic acid (CDC) and isomerization of CDC to UDC using whole cell cultures of C. absonum. In the first two approaches (using cell free systems) the yields of desired product were relatively low primarily due to the formation of various side products. The third method proved the most successful giving an overall yield of 37% (UDC) whose structure was verified by mass spectroscopy of the methyl ester.     

Arachidonic Acid Activation of Monocyte and Neutrophil Reactive Oxygen in Lung Cancer Patients Undergoing Pulmonary Resection

Reactive oxygen (roi) generation was investigated in phagocyted of 39 patients undergoing pulmonary resection for lung cancer and 39 paired healthy controls. Generation of roi in monocytes and neutrophils was monitored using 2′, 7′-dichlorofluorescein diacetate. Activation associated with hydrophobic interactions was probed by analysis of phagocyte roi activation by arachidonic acid and γ-linolenic acid. Patient roi was measured pre-operatively and 2 and 7 days post-operatively. Elevated (P<0.01) roi productin was detected in neutrophils of lung cancer patients. surgery was associated with an increase (P<0.05–P<0.01) in phagocyte roi at 2 and 7 days post-op. Phagocyte roi was stimulated by arachidonic acid and γ-linolenic acid (1–40 μ ) both pre- and post-operatively. Differences in arachidonic acid and γ-linolenic acid stimulation between patient and control and pre- and post-op patient phagocyted suggest arachidonic acid involvement in phagocyte activation during reactive responses to lung carcinoma and surgery.     

RNA cargoes associating with FMRP reveal deficits in cellular functioning in Fmr1 null mice

The Fragile X mental retardation-1 (Fmr1) gene encodes a multifunctional protein, FMRP, with intrinsic RNA binding activity. We have developed an approach, antibody-positioned RNA amplification (APRA), to identify the RNA cargoes associated with the in vivo configured FMRP messenger ribonucleoprotein (mRNP) complex. Using APRA as a primary screen, putative FMRP RNA cargoes were assayed for their ability to bind directly to FMRP using traditional methods of assessing RNA-protein interactions, including UV-crosslinking and filter binding assays. Approximately 60% of the APRA-defined mRNAs directly associate with FMRP. By examining a subset of these mRNAs and their encoded proteins in brain tissue from Fmr1 knockout mice, we have observed that some of these cargoes as well as the proteins they encode show discrete changes in abundance and/or differential subcellular distribution. These data are consistent with spatially selective regulation of multiple biological pathways by FMRP.     

A Diterpene Endoperoxide from Microtoena insuavis （Hance） Prain ex Dunn

A novel endoperoxlde diterpene, 7a-hydroxy-abieta-8（14）-en-18-oi 9α,13α-endoperoxide （compound 1）, was isolated from the stems of Microtoena insuavis （Hance） Prain ex Dunn, along with 4,4＇-dlhydroxytruxillic acid （compound 2）, gallic acid （compound 3）, ellaglc acid （compound 4）, 3-O-methylellaglc acid 3＇-O-α- rhamnopyranoslde （compound 5）, 3＂＇-O-methylcrenatoslde （compound 6）, crenatoslde （compound 7）, aptgenin （compound 8）, succinic acid （compound 9）, β-sitosterot （compound 10）, and β-daucosterol （compound 11）. The structures of these compounds were elucidated on the basis of spectral evidence.     

Isolation and characterization of an ω3-desaturation-defective mutant of an arachidonic acid-producing fungus,Mortierella alpina 1S-4

A mutant considered to be defective in the conversion of n-6 to n-3 fatty acids (3-desaturation) was derived from a 5-desaturation-defective mutant (Mut44) of Mortierella alpina 1S-4, after treating its spores with N-methyl-N-nitro-N-nitrosoguanidine. This mutant cannot produce 8(Z),11(Z),14(Z),17(Z)-eicosatetraenoic acid or any other n-3 fatty acids, of which about 10% was found in its parental strain upon cultivation at 12°C. The mutant's growth rate was comparable to that of the parental strain when grown at 28°C, but it became much slower when the mutant grew at 12°C, at which the lag phase for Mut44 was about 2 d but 5 d for the mutant.Abbreviations 18:33 9(Z),12(Z),15(Z)-octadecatrienoic acid - 18:43 6(Z),9(Z),12(Z),15(Z)-octadecatetraenoic acid - 20:43 8(Z),11(Z),14(Z),17(Z)-eicosatetraenoic acid - AA arachidonic acid - DHGA dihomo--linolenic acid - EPA 5(Z),8(Z),11(Z),14(Z),17(Z)-eicosapentaenoic acid - GLC gas-liquid chromatography - MNNG N-methyl-N-nitro-N-nitrosoguanidine - PC phosphatidylcholine     

Usefulness of Glucokinase from Bacillus stearothermophilus for the Enzymatic Measurement of Magnesium in Human Serum

(22R,23R,24S)-3α,5-Cyclo-22,23-diacetoxy-5a-ergostan-6-one (2b) is a new key intermediate of some naturally occurring brassinosteroids such as brassinolide (la), castasterone (lb), teasterone (lc) and typhasterol (Id). The cycloketone 2b was prepared in 10 steps via (22R,23R,24S)-6p- benzyloxy-3a,5-cyclo-22,23-dihydroxy-5a-ergostane (5) from stigmasterol. 2b was treated with a catalytic amount of /7-toluenesulfonic acid and sodium bromide to give an enone (7b), which was oxidized with osmium tetroxide and derived to give a 2a,3a-acetonide (8b). 8b was easily separated from its isomer by the use of silica gel column chromatography. 8b was oxidized with tri- fluoroperacetic acid and deacetylated to give la. 8b was deacetylated and deacetonized to give lb. 2b was treated with dilute sulfuric acid in acetic acid to give a 3/^-acetate (10). 10 was treated with sodium hydroxide to give lc. 2b was treated with hydrobromic acid to give a 3/i-bromide (12), which was treated with silver acetate to give a 3a-acetate (13). 13 was treated with sodium hydroxide to give Id.     

Chemical variation in the lichen genus <Emphasis Type="Italic">Letrouitia</Emphasis> (Ascomycota,Letrouitiaceae)

Secondary metabolites from 193 specimens belonging to 15 species of Letrouitia were analyzed by HPLC. Significant quantities of the anthraquinones parietin and fragilin were found in most species and occasionally minor quantities of emodin, 5-chloroemodin, 7-chloroemodin, 7-chloroteloschistin, 7-chlorofallacinal and 7-chloroparietinic acid were present. Eight previously unknown lichen substances were identified. A chemotype containing seven new dibenzofurans (8-chlorodioxocondidymic acid, 8-chlorodioxodidymic acid, 8-chloroxodidymic acid, dioxocondidymic acid, dioxodidymic acid, letrouitic acid and oxodidymic acid) was found in 3 species. In addition, a chemotype containing four unknowns (possibly chlorodepsidones) occurred in L. subvulpina. Eight different chemotypes were identified in the genus. The secondary chemistry was important for the precise identification of some species in Letrouitia. The similarity in secondary chemistry between Letrouitiaceae and Teloschistaceae is not particularly strong, as the shared compounds are also known to occur in several other lichen families.     

Novel Neolignan from Penthorum chinense

A new neolignan （7＇E）-2＇,4,8-trihydroxy-3-methoxy-2,4＇-epoxy-8,5＇-neolign-7＇-en-7-one （1） was isolated from the whole plants of Penthorum chinense Pursh, along with Iupeol （2）, betulinic acid （3）, glyceryl monopalmitate （4）, β-sitosterol （5）, palmitic acid （5）, ursolic acid （7）, 2β,3β,23-trihydroxy-urs-12-ene-28-oic acid （8）, glyceryl monolaurate （9）, scopoletin （10）, （-）syringaresinol （11）, 9,9＇-O-diferuIoyl-（-）-secoisolariciresionl （12）, pinocembrin （13）, apigenin （14）, kaempferol （15）, Iuteolin （16）, β-daucosterol （17）, quercetin （18）, 1-O-（β-D-glucopyranosyl）-（2S, 2＇R, 3R,4E,8E）-2-（2＇-hydroxyhexadecanoy- lamino）-4,8-octdecadiene-1,3-diol （19）, gallic acid （20）, pinocembrin-7-O-β-D-glucoside （21）, and quercetin-3-O-β-D- glucoside （22）. The structures of these compounds were elucidated on the basis of chemical and spectral evidence.     

Traits of fatty acid accumulation in dimorphic seeds of the euhalophyte Suaeda salsa in saline conditions

The mechanism on of how salinity affects seed fatty acids accumulation remains unclear in halophytes. The present results revealed that the content of total unsaturated fatty acids in black seeds was higher than in brown seeds in the euhalophyte Suaeda salsa under controlled saline conditions. Salinity (200?mM NaCl) significantly increased the total oil content, unsaturated acid/saturated acid ratio, and content of α-linolenic acid (C18:3) (ALA), especially in brown seeds. The most abundant fatty acid in dimorphic seeds is linoleic acid (C18:2) (>70%). It appears that more ALA accumulated in brown seeds compared to black seeds. The enzyme activity of omega-3 fatty acid desaturase (ω-3 FAD) in brown seeds was much higher than that in black seeds, but salinity had no significant effect on the activity of ω-3 FAD in both brown and black seeds. The relative expression of SsFAD7 was increased by salinity, and the value in brown seeds was much higher than that in black seeds. This means salinity can, salinity can improve the quantity of fatty acids in dimorphic seeds of S. salsa, and the enzyme of ω-3 FAD and SsFAD7 may involve in the accumulation of ALA in dimorphic seeds under salinity.     

Phytochemical Investigation and Cytotoxic Evaluation of the Components of the Medicinal Plant Ligularia atroviolacea

A phytochemical investigation of the roots of Ligularia atroviolacea resulted in the isolation of 24 compounds including seven new eremophilanoids named eremophila‐3,7(11),8‐triene‐12,8;14,6α‐diolide ( 1 ), 3β‐(angeloyloxy)eremophil‐7(11)‐en‐12,8β‐olid‐14‐oic acid ( 2 ), 1α‐chloro‐10β‐hydroxy‐6β‐(2‐methylpropanoyloxy)‐9‐oxo‐7,8‐furoeremophilane ( 3 ), (10βH)‐8‐oxoeremophila‐3(4),6(7)‐diene‐12,14‐dioic acid ( 4 ), (10αH)‐8‐oxoeremophila‐3(4),6(7)‐diene‐12,14‐dioic acid ( 5 ), 8β‐[eremophila‐3′,7′(11′)‐diene‐12′,8′α;14′,6′α‐diolide]eremophila‐3,7(11)‐diene‐12,8α;14,6α‐diolide ( 6 ), and ligulatrovine A ( 7 ), eleven known eremophilanoids, 8 – 18 , four steroids, one glucose derivative, and one fatty acid. The structures of these compounds were elucidated by spectroscopic methods including 2D‐NMR experiments. The structure of 3 was also established by an X‐ray diffraction study. The in vitro cytotoxicity evaluation of selected compounds was performed on seven cultured tumor cell lines, i.e., KB, BEL‐7404, A549, HL‐60, HeLa, CNE, and P‐388D1. The preliminary taxonomy of this species was also discussed, and the possible biogenesis of a dimer possessing a new noreremophilanoid type skeleton, 7 , is presented in a preliminary form.     

Identifying the mechanism of Escherichia coli O157:H7 survival by the addition of salt in the treatment with organic acids

Aim

In this study, the effects of the addition of salt to treatment with acids (one of several organic acids and salt in various solutions including rich or minimal broth, buffer, or distilled water) on the reduction of Escherichia coli O157:H7 were investigated. The protein expression profiles corresponding to acid stress (acetic acid) with or without salt addition were studied using a comparative proteomic analysis of E. coli O157:H7.

Methods and Results

When acetic, lactic, or propionic acid was combined with 3% NaCl, mutually antagonistic effects of acid and salt on viability of E. coli O157:H7 were observed only in tryptone and yeast extract broth. After exposure to acetic acid alone or in combination with salt, approximately 851 and 916 protein spots were detected, respectively. Analysis of 10 statistically significant differentially expressed proteins revealed that these proteins are mainly related to energy metabolism.

Conclusions

When we compared protein expression of E. coli O157:H7 treated with acetic acid and the combination of the acid and salt, the differentially expressed proteins were not related to acid stress‐ and salt stress‐inducible proteins such as stress shock proteins.

Significance and Impact of the Study

According to these results, the increased resistance of E. coli O157:H7 to acetic acid after the addition of salt may not be the result of synthesis of proteins related to these phenomena; therefore, further research needs to be conducted to identify the mechanism of the mutually antagonistic effect of some organic acids and salt.     

Multi‐enzymatic one‐pot reduction of dehydrocholic acid to 12‐keto‐ursodeoxycholic acid with whole‐cell biocatalysts

Ursodeoxycholic acid (UDCA) is a bile acid of industrial interest as it is used as an agent for the treatment of primary sclerosing cholangitis and the medicamentous, non‐surgical dissolution of gallstones. Currently, it is prepared industrially from cholic acid following a seven‐step chemical procedure with an overall yield of <30%. In this study, we investigated the key enzymatic steps in the chemo‐enzymatic preparation of UDCA—the two‐step reduction of dehydrocholic acid (DHCA) to 12‐keto‐ursodeoxycholic acid using a mutant of 7β‐hydroxysteroid dehydrogenase (7β‐HSDH) from Collinsella aerofaciens and 3α‐hydroxysteroid dehydrogenase (3α‐HSDH) from Comamonas testosteroni. Three different one‐pot reaction approaches were investigated using whole‐cell biocatalysts in simple batch processes. We applied one‐biocatalyst systems, where 3α‐HSDH, 7β‐HSDH, and either a mutant of formate dehydrogenase (FDH) from Mycobacterium vaccae N10 or a glucose dehydrogenase (GDH) from Bacillus subtilis were expressed in a Escherichia coli BL21(DE3) based host strain. We also investigated two‐biocatalyst systems, where 3α‐HSDH and 7β‐HSDH were expressed separately together with FDH enzymes for cofactor regeneration in two distinct E. coli hosts that were simultaneously applied in the one‐pot reaction. The best result was achieved by the one‐biocatalyst system with GDH for cofactor regeneration, which was able to completely convert 100 mM DHCA to >99.5 mM 12‐keto‐UDCA within 4.5 h in a simple batch process on a liter scale. Biotechnol. Bioeng. 2013; 110: 68–77. © 2012 Wiley Periodicals, Inc.     

Expression of a gene for plastid ω-3 fatty acid desaturase and changes in lipid and fatty acid compositions in light- and dark- grown wheat leaves

The leaves of monocotyledonous plants create a developmental sequence of cells and plastids from the base to the apical portion. We investigated fatty-acid and lipid compositions in successive leaf sections of light- and dark-grown wheat (Triticum aestivum L. cv. Chihoku) seedlings. The most notable change in the fatty acid composition was the increase of linolenic acid (18:3) with maturation of leaf cells, which occurred both in light- and dark-grown leaf tissues. In light-grown leaves, the increase of 18:3 with maturation was mainly attributed to the increase of monogalactosyldiacylglycerol (MGD) and also to the increase of the 18:3 level of MGD. In dark-grown leaves, the increase of 18:3 in the leaf apex was caused by the increase of the levels of MGD and digalactosyldiacylglycerol (DGD) and also by the increase of the 18:3 levels of within these two lipids. Since MGD and DGD are mainly found in plastid membranes, these findings indicate that both the synthesis of galactolipids and the formation of 18:3 these lipids take place during plastid development. The plastid ω-3 fatty acid desaturase is responsible for the formation of 18:3 in plastid membrane lipids. To investigate the regulation of desaturation, we isolated a gene for wheat plastid ω-3 fatty acid desaturase (TaFAD7). The mRNA level of TaFAD7 in light-grown leaves was much higher than that in dark-grown leaves. During the greening of etiolated leaves the level of TaFAD7 mRNA increased significantly, accompanied by an increase of the 18:3 level of total fatty acids. On the other hand, the levels of TaFAD7 mRNA were almost the same in all the leaf sections of both light- and dark-grown leaf tissues. These results suggest that the effect of the expression of the TaFAD7 gene on the increase of the 18:3 level is different between the leaf development under continuous light- or dark-conditions and the light-induced greening process of etiolated leaves. The increase of 18:3 content of MGD (or MGD and DGD) with maturation is apparently regulated not solely by the level of TaFAD7 mRNA.     

Transformation of Bile Acids by Mixed Microbial Cultures from Human Feces and Bile Acid Transforming Activities of Isolated Bacterial Strains

Microbial transformation of cholic acid and chenodeoxycholic acid by anaerobic mixed cultures of human fecal microorganisms was investigated, and the results were examined in relation to the bile acid transforming activities of 75 bacterial strains isolated from the same fecal cultures. The reactions involved in the mixed cultures were dehydrogenation and dehydroxylation of the 7α-hydroxy group in both primary bile acids and epimerization of the 3α-hydroxy group in all metabolic bile acids. Extensive epimerization of the 7α-hydroxy group of chenodeoxycholic acid yielding ursodeoxycholic acid was also demonstrated by certain fecal samples. 7α-Dehydrogenase activity was widespread among the fecal isolates (88% of 16 facultative anaerobes and 51% of 59 obligate anaerobes), and 7α-dehydroxylase activity was revealed in one of the isolates, an unidentified gram-positive nonsporeforming anaerobic bacterium. 3α-Epimerization was effected by seven strains assigned to Eubacterium lentum, which were also active for 3α- and 7α-dehydrogenations. No microorganism accounting for 7α-epimerization was recovered among the isolates. Splitting of conjugated bile acid was demonstrated by the majority of obligate anaerobes but the activity was rare among facultative anaerobes.     

Identification and Biological Evaluation of Secondary Metabolites from the Endolichenic Fungus Aspergillus versicolor

A chemical investigation of the endolichenic fungus Aspergillus versicolor (125a), which was found in the lichen Lobaria quercizans, resulted in the isolation of four novel diphenyl ethers, named diorcinols F–H ( 1 – 3 , resp.) and 3‐methoxyviolaceol‐II ( 4 ), eight new bisabolane sesquiterpenoids, named (?)‐(R)‐cyclo‐hydroxysydonic acid ( 5 ), (?)‐(7S,8R)‐8‐hydroxysydowic acid ( 6 ), (?)‐(7R,10S)‐10‐hydroxysydowic acid ( 7 ), (?)‐(7R,10R)‐iso‐10‐hydroxysydowic acid ( 8 ), (?)‐12‐acetoxy‐1‐deoxysydonic acid ( 9 ), (?)‐12‐acetoxysydonic acid ( 10 ), (?)‐12‐hydroxysydonic acid ( 11 ), and (?)‐(R)‐11‐dehydrosydonic acid ( 12 ), two new tris(pyrogallol ethers), named sydowiols D ( 13 ) and E ( 14 ), and fifteen known compounds, 15 – 29 . All of the structures were determined by spectroscopic analyses, and a number of them were further identified through chemical transformations and electronic circular dichroism (ECD) calculations. Preliminary bioassays of these isolates for the determination of their inhibitory activities against the fungus Candida albicans, and their cytotoxicities against the human cancer cell lines PC3, A549, A2780, MDA‐MB‐231, and HEPG2 were also evaluated.