Secondary metabolites of the aspen fungus Stachybotrys cylindrospora

1993 ◽  
Vol 71 (4) ◽  
pp. 487-493 ◽  
Author(s):  
William A. Ayer ◽  
Shichang Miao

The secondary metabolites produced by the fungus Stachybotrys cylindrospora, which is known to be strongly antagonistic to the blue-stain fungus Ceratocystiopsis crassivaginata, have been examined. The compounds responsible for the antifungal activity are trichodermin (5) and trichodermol (6), two previously known mycotoxins belonging to the trichothecene family. The other metabolites, stachybotrydial (1), stachybotramide (8), and 6,8-dihydroxy-3,5,7-trimethylisochroman (7), although not active against C. crassivaginata, are new natural products. The structures of the new compounds were established by spectroscopic techniques.

2021 ◽  
Author(s):  
◽  
Taitusi Taufa

<p>This thesis describes the isolation and structure elucidation of 15 new secondary metabolites from Tongan and New Zealand marine sponges. A total of 18 sponge specimens were subjected to an NMR-based screening method, of which four were analysed in detail. Examination of a two-sponge association, Stelletta crater and Desmacella dendyi from New Zealand, resulted in the isolation of two new 4-methylenesterols, craterols A (94) and B (95). To the best of the author’s knowledge, compounds 94 and 95 represent the first secondary metabolites to be reported from either species. Both 94 and 95 possess a double bond between C-5 and C-6, a feature that is unprecedented in this subgroup of marine natural products. An investigation of a Tongan sponge Zyzzya fuliginosa afforded two new pyrroloquinoline alkaloids, 6-bromodamirone B (182) and makaluvamine W (183). Makaluvamine W (183) contains an oxazole moiety, which is uncommon in this group of natural products. Both 182 and 183 lacked activity against the human promyelocytic leukemia cells (HL-60). Five new compounds were isolated from a Tongan sponge of the genus Leucetta, including two glycerol lipids (238 and 239), three glycerol ethers (244–246) and an imidazole alkaloid (243). Naamidine K (243) is a new addition to the naamidine family, while the glycerol metabolites are non-imidazole alkaloid additions to the group of compounds reported from this genus. A spectroscopic investigation into the Tongan sponge Cacospongia mycofijiensis yielded four new zampanolide analogues (282–285) and a new oxygenated sesquiterpene, isodictyodendrillin A (280). The isolation of the zampanolide analogues gives insight into the structure-activity relationship (SAR) in this family of compounds. Zampanolides B–D (282–284) displayed potent antiproliferative activity towards HL-60 cell lines in the low nanomolar range (3–5 nM), while zampanolide E (285) was significantly less potent with an IC50 value of 306 nM. In addition, the re-isolation of dactylolide (281) and zampanolide A (278) from this sponge, established a firm conclusion regarding the controversial configuration of dactylolide (281), which possesses the same absolute configuration as (–)-zampanolide A (278) and has a levorotatory optical rotation.</p>


2021 ◽  
Author(s):  
◽  
Victoria Helen Woolner

<p>During the course of this study, Tongan marine organisms were investigated for new secondary metabolites. A combination of reversed- and normal-phase chromatographic techniques and NMR spectroscopy was employed, to aid in the isolation and structure elucidation of the five known and four new compounds isolated in this study. A brief investigation into the antifungal activity of Tongan holothurian saponins was instigated in order to compare the activity against saponins isolated from the common New Zealand sea cucumber, Australostichopus mollis. A yeast-based chemical genetics study, determined the antifungal activity, for four partially purified Tongan holothurian extracts, against Saccharomyces cerevisiae, to be similar to neothyonidioside (44), a saponin from A. mollis. This result suggested the antifungal activity to be a common characteristic to sea cucumber saponins. Further interest in secondary metabolites from Tongan marine organisms led this study towards the investigation of Tongan marine sponges. Five sponges were selected for screening, and two chosen for further study which yielded five known compounds (51–53, 61, 62) and four new fascaplysin derivatives; 7-bromoreticulatine,10-bromo-6,7-dimethoxyhomofascaplysin C,10-bromo-6, 7-dimethoxyhomofascaplysin D, and 10-bromohomofascaplysin A (63–66, respectively). Although 63 and 66 are new members of the fascaplysin family solely due to the position of the bromine, it appears that bromination on the A-ring is comparatively rare, with only three of the 24 literature examples displaying A-ring bromination. On the other hand, 64 and 65 present a new sub-class of fascaplysin derivatives due to the presence of a dimethoxy functionality. Both 7-bromoreticulatine (63) and 10-bromohomofascaplysin A (66) were found to be potently cytotoxic in the HL-60 cell line, exhibiting IC50 values of 33.8 and 498 nM, respectively. 10-Bromo-6,7-dimethoxyhomofascaplysins C (64) and D (65) were significantly less cytotoxic with respective IC₅₀ values of 2.7 and 6.0 μΜ. (Abstract continues with diagrams).</p>


1984 ◽  
Vol 39 (7-8) ◽  
pp. 710-713 ◽  
Author(s):  
Eckhard Wollenweber ◽  
Gisela Kohorst

Abstract Leaves of a number of Ericaceous plants have a thin epicuticular layer that consists mostly of triterpenes. In Kalmia angustifolia, K. latifolia and K. polifolia as well as in Gaultheria procumbens and G. shallon this material also contains trace amounts of flavonoid aglycones. In Kalmia they are the 3-OMe-derivatives of four C-methyl flavones reported previously as the typical leaf-wax flavonoids of Eucalyptus. The new compounds, 5-OH-3,7,4′-triOMe-6,8-diCH3-flavone (kalmiatin), 5-OH-3,7,4′-triOMe-6-CH3-flavone (8-desmethyl-kalmiatin), 5,4′-diOH-3,7-diOMe-6,8-diCH3-flavone (latifolin) and 5,4′-diOH-3,7-diOMe-6-CH3-flavone (8-desmethyl-latifolin) are novel natural products. They could not be detected in eight species of Eucalyptus. A screening of 15 species of Ericaceae revealed that 8-desmethyl-sideroxylin and 8-desmethyl-latifolin are present also in the epicuticular layer on leaves of Gaultheria procumbens, while on G. shallon and on Andromeda polifolia traces of galangin-3-methyl ether were found. In the other species checked no external flavonoid aglycones could be detected.


1996 ◽  
Vol 51 (11-12) ◽  
pp. 802-806 ◽  
Author(s):  
Gudrun Schneider ◽  
Heidrun Anke ◽  
Olov Sterner

Xylaramide (1), possessing potent antifungal activity towards Nematospora coryli and Saccharomyces cerevisiae, was isolated from the culture fluids of the wood-inhabiting ascomycete Xylaria longipes together with tyrosol (2), 2,5-bis(hydroxymethyl)furan (3) and 2-hexylidene- 3-methylsuccinic acid (4). The latter has been known as a Xylaria metabolite for many years. Compounds 2 and 3 have been previously reported from other fungi, whereas 1 is a new natural N -(2-phenylethenyl)-2-hydroxypropanamide. The isolation, structure determination and biological properties of xylaramide are described. The biological activities of the other compounds are included.


1998 ◽  
Vol 53 (11-12) ◽  
pp. 939-945 ◽  
Author(s):  
Kerstin Fabian ◽  
Kirsten Lorenzen ◽  
Timm Anke ◽  
Martin Johansson ◽  
Olov Sterner

Abstract The three protoilludanes radulone A (1), radulone B (2) and radudiol (3), the illudalane radulactone (4) and the illudane radulol (5) were isolated from the extracts of the culture fluids of the basidiomycete Radulomyces confluens. The structures of the five new compounds were determined by spectroscopic techniques. Radulone A (1) is a potent inhibitor of human and bovine platelet aggregation stimulated by different agonists, inhibiting preferentially the aggregation of human platelets induced by ADP with an IC50 value of 2 μᴍ . In addition 1 exhibits cytotoxic and antimicrobial activities. The other four compounds exhibited weak antimicrobial and cytotoxic activity.


2021 ◽  
Author(s):  
◽  
Victoria Helen Woolner

<p>During the course of this study, Tongan marine organisms were investigated for new secondary metabolites. A combination of reversed- and normal-phase chromatographic techniques and NMR spectroscopy was employed, to aid in the isolation and structure elucidation of the five known and four new compounds isolated in this study. A brief investigation into the antifungal activity of Tongan holothurian saponins was instigated in order to compare the activity against saponins isolated from the common New Zealand sea cucumber, Australostichopus mollis. A yeast-based chemical genetics study, determined the antifungal activity, for four partially purified Tongan holothurian extracts, against Saccharomyces cerevisiae, to be similar to neothyonidioside (44), a saponin from A. mollis. This result suggested the antifungal activity to be a common characteristic to sea cucumber saponins. Further interest in secondary metabolites from Tongan marine organisms led this study towards the investigation of Tongan marine sponges. Five sponges were selected for screening, and two chosen for further study which yielded five known compounds (51–53, 61, 62) and four new fascaplysin derivatives; 7-bromoreticulatine,10-bromo-6,7-dimethoxyhomofascaplysin C,10-bromo-6, 7-dimethoxyhomofascaplysin D, and 10-bromohomofascaplysin A (63–66, respectively). Although 63 and 66 are new members of the fascaplysin family solely due to the position of the bromine, it appears that bromination on the A-ring is comparatively rare, with only three of the 24 literature examples displaying A-ring bromination. On the other hand, 64 and 65 present a new sub-class of fascaplysin derivatives due to the presence of a dimethoxy functionality. Both 7-bromoreticulatine (63) and 10-bromohomofascaplysin A (66) were found to be potently cytotoxic in the HL-60 cell line, exhibiting IC50 values of 33.8 and 498 nM, respectively. 10-Bromo-6,7-dimethoxyhomofascaplysins C (64) and D (65) were significantly less cytotoxic with respective IC₅₀ values of 2.7 and 6.0 μΜ. (Abstract continues with diagrams).</p>


2021 ◽  
Author(s):  
◽  
Taitusi Taufa

<p>This thesis describes the isolation and structure elucidation of 15 new secondary metabolites from Tongan and New Zealand marine sponges. A total of 18 sponge specimens were subjected to an NMR-based screening method, of which four were analysed in detail. Examination of a two-sponge association, Stelletta crater and Desmacella dendyi from New Zealand, resulted in the isolation of two new 4-methylenesterols, craterols A (94) and B (95). To the best of the author’s knowledge, compounds 94 and 95 represent the first secondary metabolites to be reported from either species. Both 94 and 95 possess a double bond between C-5 and C-6, a feature that is unprecedented in this subgroup of marine natural products. An investigation of a Tongan sponge Zyzzya fuliginosa afforded two new pyrroloquinoline alkaloids, 6-bromodamirone B (182) and makaluvamine W (183). Makaluvamine W (183) contains an oxazole moiety, which is uncommon in this group of natural products. Both 182 and 183 lacked activity against the human promyelocytic leukemia cells (HL-60). Five new compounds were isolated from a Tongan sponge of the genus Leucetta, including two glycerol lipids (238 and 239), three glycerol ethers (244–246) and an imidazole alkaloid (243). Naamidine K (243) is a new addition to the naamidine family, while the glycerol metabolites are non-imidazole alkaloid additions to the group of compounds reported from this genus. A spectroscopic investigation into the Tongan sponge Cacospongia mycofijiensis yielded four new zampanolide analogues (282–285) and a new oxygenated sesquiterpene, isodictyodendrillin A (280). The isolation of the zampanolide analogues gives insight into the structure-activity relationship (SAR) in this family of compounds. Zampanolides B–D (282–284) displayed potent antiproliferative activity towards HL-60 cell lines in the low nanomolar range (3–5 nM), while zampanolide E (285) was significantly less potent with an IC50 value of 306 nM. In addition, the re-isolation of dactylolide (281) and zampanolide A (278) from this sponge, established a firm conclusion regarding the controversial configuration of dactylolide (281), which possesses the same absolute configuration as (–)-zampanolide A (278) and has a levorotatory optical rotation.</p>


2021 ◽  
Author(s):  
Nimsi Campos-Xolalpa ◽  
Julia Pérez-Ramos ◽  
Ana Esquivel-Campos ◽  
Cuauhtemoc Pérez-González ◽  
Leonor Sánchez-Pérez ◽  
...  

Cancer is a group of related diseases in which there is uncontrolled cell growth that spreads to the surrounding tissues and damages them. Cancer remains the disease with the leading cause of death worldwide, and incidence and mortality are increasing rapidly. The main cancer treatment is chemotherapy; however, the compounds used in this treatment have serious side effects for this reason, is necessary to develop new therapeutic strategies. Natural products are an excellent pharmacological alternative for the treatment of cancer and infections. In search of new compounds with cytotoxic and antimicrobial activity, we have found quinones that have a high pharmacological potency in the treatment of these health problems. Quinones are an aromatic system of one or diketone and are mainly isolated from plants, fungi, bacteria, and other organisms. These compounds are secondary metabolites derived from the oxidation of hydroquinones; they include benzoquinones, naphthoquinones, anthraquinones, and polyquinones. This review summarizes the activity of 152 anticancer and 30 antimicrobial quinones.


Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 873
Author(s):  
Balasubramanian Cibichakravarthy ◽  
Polapass Arul Jose

Streptomyces are the most prolific source of structurally diverse microbial natural products. Advancing genome-based analysis reveals the previously unseen potential of Streptomyces to produce numerous novel secondary metabolites, which allows us to take natural product discovery to the next phase. However, at present there is a huge disproportion between the rate of genome reports and discovery of new compounds. From this perspective of harnessing the enduring importance of Streptomyces, we discuss the recent genome-directed advancements inspired by hidden biosynthetic wealth that provide hope for future antibiotics.


Metabolites ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 107
Author(s):  
Rafael de Felício ◽  
Patricia Ballone ◽  
Cristina Freitas Bazzano ◽  
Luiz F. G. Alves ◽  
Renata Sigrist ◽  
...  

Bacterial genome sequencing has revealed a vast number of novel biosynthetic gene clusters (BGC) with potential to produce bioactive natural products. However, the biosynthesis of secondary metabolites by bacteria is often silenced under laboratory conditions, limiting the controlled expression of natural products. Here we describe an integrated methodology for the construction and screening of an elicited and pre-fractionated library of marine bacteria. In this pilot study, chemical elicitors were evaluated to mimic the natural environment and to induce the expression of cryptic BGCs in deep-sea bacteria. By integrating high-resolution untargeted metabolomics with cheminformatics analyses, it was possible to visualize, mine, identify and map the chemical and biological space of the elicited bacterial metabolites. The results show that elicited bacterial metabolites correspond to ~45% of the compounds produced under laboratory conditions. In addition, the elicited chemical space is novel (~70% of the elicited compounds) or concentrated in the chemical space of drugs. Fractionation of the crude extracts further evidenced minor compounds (~90% of the collection) and the detection of biological activity. This pilot work pinpoints strategies for constructing and evaluating chemically diverse bacterial natural product libraries towards the identification of novel bacterial metabolites in natural product-based drug discovery pipelines.


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