Conversion of Gibberellic Acid into the B-Ring seco-Kaurenoid, Longirabdolactone

2003 ◽  
Vol 56 (8) ◽  
pp. 805 ◽  
Author(s):  
George Adamson ◽  
Lewis N. Mander
Keyword(s):  
Secondary Metabolites ◽  
Gibberellic Acid ◽  
Ring Expansion ◽  
Reaction Conditions ◽  
Bioactive Secondary Metabolites ◽  
Synthetic Target

The base-catalyzed rearrangement of an α-hydroxy aldehyde derived from the gibberellin GA15 results in ring-expansion of the five-membered B-ring of the gibberellin molecule and transformation into an ent-kaurene derivative. Further manipulation affords 19,7-acetals and access to the highly functionalized B-ring seco-kaurenoid bioactive secondary metabolites that have been isolated from the genus Rabdosia. The methodology is illustrated by the synthesis of longirabdolactone from gibberellic acid. Unanticipated and unobserved epimerization at C5 led initially to the 5-epimer of the synthetic target by a series of ketol rearrangements, but the isomerization could be avoided through the use of milder reaction conditions.

scholarly journals Chemoenzymatic One-Pot Process for the Synthesis of Tetrahydroisoquinolines

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1389
Author(s):  
Andreas Sebastian Klein ◽  
Anna Christina Albrecht ◽  
Jörg Pietruszka
Keyword(s):  
Secondary Metabolites ◽  
Chemical Synthesis ◽  
Amino Alcohol ◽  
Phosphate Buffer ◽  
Reaction Pathways ◽  
Reaction Conditions ◽  
One Pot ◽  
Benzylic Alcohols ◽  
Bioactive Secondary Metabolites ◽  
Common Laboratory

1,2,3,4-Tetrahydyroisoquinolines form a valuable scaffold for a variety of bioactive secondary metabolites and commercial pharmaceuticals. Due to the harsh or complex conditions of the conventional chemical synthesis of this molecular motif, alternative mild reaction pathways are in demand. Here we present an easy-to-operate chemoenzymatic one-pot process for the synthesis of tetrahydroisoquinolines starting from benzylic alcohols and an amino alcohol. We initially demonstrate the oxidation of 12 benzylic alcohols by a laccase/TEMPO system to the corresponding aldehydes, which are subsequently integrated in a phosphate salt mediated Pictet–Spengler reaction with m-tyramine. The reaction conditions of both individual reactions were analyzed separately, adapted to each other, and a straightforward one-pot process was developed. This enables the production of 12 1,2,3,4-tetrahydyroisoquinolines with yields of up to 87% with constant reaction conditions in phosphate buffer and common laboratory glass bottles without the supplementation of any additives.

Bioactive Secondary Metabolites from Geosmithia langdonii

Planta Medica ◽  
2013 ◽  
Vol 79 (10) ◽  
Author(s):  
LG Malak ◽  
DW Bishay ◽  
AM Abdel-baky ◽  
AM Moharram ◽  
SJ Cutler ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Bioactive Secondary Metabolites

Screening bioactive secondary metabolites from Costa Rican enviromental microbial communities

Planta Medica ◽  
2015 ◽  
Vol 81 (11) ◽  
Author(s):  
JJ Araya ◽  
M Chavarría ◽  
A Pinto-Tomás ◽  
C Murillo ◽  
L Uribe ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Microbial Communities ◽  
Costa Rican ◽  
Bioactive Secondary Metabolites

Bioactive Secondary Metabolites from Endophytic Fungi

2020 ◽  
Vol 27 (11) ◽  
pp. 1836-1854 ◽  
Author(s):  
Elena Ancheeva ◽  
Georgios Daletos ◽  
Peter Proksch
Keyword(s):  
Secondary Metabolites ◽  
Endophytic Fungi ◽  
Host Plants ◽  
Biological Activities ◽  
Cytotoxic Agents ◽  
Special Focus ◽  
Plant Metabolites ◽  
Direct Production ◽  
Bioactive Secondary Metabolites ◽  
Fungal Genes

Background: Endophytes represent a complex community of microorganisms colonizing asymptomatically internal tissues of higher plants. Several reports have shown that endophytes enhance the fitness of their host plants by direct production of bioactive secondary metabolites, which are involved in protecting the host against herbivores and pathogenic microbes. In addition, it is increasingly apparent that endophytes are able to biosynthesize medicinally important “phytochemicals”, originally believed to be produced only by their host plants. Objective: The present review provides an overview of secondary metabolites from endophytic fungi with pronounced biological activities covering the literature between 2010 and 2017. Special focus is given on studies aiming at exploration of the mode of action of these metabolites towards the discovery of leads from endophytic fungi. Moreover, this review critically evaluates the potential of endophytic fungi as alternative sources of bioactive “plant metabolites”. Results: Over the past few years, several promising lead structures from endophytic fungi have been described in the literature. In this review, 65 metabolites are outlined with pronounced biological activities, primarily as antimicrobial and cytotoxic agents. Some of these metabolites have shown to be highly selective or to possess novel mechanisms of action, which hold great promises as potential drug candidates. Conclusion: Endophytes represent an inexhaustible reservoir of pharmacologically important compounds. Moreover, endophytic fungi could be exploited for the sustainable production of bioactive “plant metabolites” in the future. Towards this aim, further insights into the dynamic endophyte - host plant interactions and origin of endophytic fungal genes would be of utmost importance.

Streptomyces: host for refactoring of diverse bioactive secondary metabolites

3 Biotech ◽  
2021 ◽  
Vol 11 (7) ◽  
Author(s):  
Vivek Sharma ◽  
Randhir Kaur ◽  
Richa Salwan
Keyword(s):  
Secondary Metabolites ◽  
Bioactive Secondary Metabolites

scholarly journals Species Diversity and Secondary Metabolites of Sarcophyton-Associated Marine Fungi

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3227
Author(s):  
Yuanwei Liu ◽  
Kishneth Palaniveloo ◽  
Siti Aisyah Alias ◽  
Jaya Seelan Sathiya Seelan
Keyword(s):  
Secondary Metabolites ◽  
Soft Coral ◽  
Marine Fungi ◽  
Indole Alkaloids ◽  
Structural Diversity ◽  
Future Research ◽  
Soft Corals ◽  
Diverse Range ◽  
Symbiotic Relationships ◽  
Bioactive Secondary Metabolites

Soft corals are widely distributed across the globe, especially in the Indo-Pacific region, with Sarcophyton being one of the most abundant genera. To date, there have been 50 species of identified Sarcophyton. These soft corals host a diverse range of marine fungi, which produce chemically diverse, bioactive secondary metabolites as part of their symbiotic nature with the soft coral hosts. The most prolific groups of compounds are terpenoids and indole alkaloids. Annually, there are more bio-active compounds being isolated and characterised. Thus, the importance of the metabolite compilation is very much important for future reference. This paper compiles the diversity of Sarcophyton species and metabolites produced by their associated marine fungi, as well as the bioactivity of these identified compounds. A total of 88 metabolites of structural diversity are highlighted, indicating the huge potential these symbiotic relationships hold for future research.

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