Cespitulins A–D, novel diterpenoids from Taiwanese Cespitularia taeniata

Chemical and biological profile of Cespitularia species: A mini review

Soft corals belonging to the genus Cespitularia have been well recognized as a rich source of bioactive secondary metabolites especially diterpenoids. This review furnishes an overview of all naturally isolated compounds from Cespitularia genus as, diterpenoids, nitrogen-containing diterpenes, sesquiterpenoids and steroids as well as biological activities of these species. Cespitularia species have been studied for their anticancer, immunomodulatory, antiviral, antimicrobial, and anti-inflammatory activities. This work is the first review published on this topic.

Biodegradable siderophores: survey on their production, chelating and complexing properties

The academic and industrial research on the interactions of complexing agents with the environment has received more attention for more than half a century ago and has always been concerned with the applications of chelating agents in the environment. In contrast, in recent years, an increasing scholarly interest has been demonstrated in the chemical and biological degradation of chelating agents. This is reflected by the increasing number of chelating agents-related publications between 1950 and middle of 2016. Consequently, the discovery of new green biodegradable chelating agents is of great importance and has an impact in the non-biodegradable chelating agent’s replacement with their green chemistry analogs. To acquire iron, many bacteria growing aerobically, including marine species, produce siderophores, which are low-molecular-weight compounds produced to facilitate acquisition of iron. To date and to the best of our knowledge, this is a concise and complete review article of the current and previous relevant studies conducted in the field of production, purification of siderophore compounds and their metal complexes, and their roles in biology and medicine.

Nitrogen-Containing Diterpenoids, Sesquiterpenoids, and Nor-Diterpenoids from Cespitularia taeniata

Two new nitrogen-containing verticillene diterpenoids, cespilamides A and B (1 and 2), three new nitrogen-containing sesquiterpenoids, cespilamides C-E (3-5), and five new norverticillene and verticillene diterpenoids, cespitaenins A-E (6-10), were isolated from the Taiwanese soft coral Cespitularia taeniata. Compound 1 possesses an unusual oxazo ring system at C-10 while compound 2 displays an unprecedented C-C bond cleavage between C-10 and C-11 with an N-ethylphenyl group at C-10. Biogenetic pathways of 1 and 2 are proposed. The absolute configuration of 1 was confirmed by Mosher's method and molecular mechanics calculations (MM2). The cytotoxicities of compounds 1-10 were evaluated against a small panel of human cancer cell lines.

Cespitulones A and B, cytotoxic diterpenoids of a new structure class from the soft coral Cespitularia taeniata

Two novel diterpenoids, cespitulones A (1) and B (2), were isolated from extracts of the soft coral Cespitularia taeniata. Both compounds possess an unprecedented bicyclo [10.3.1] ring system with C-C bond connections between C-10 and C-20, and between C-20 and C-11. Their structures were elucidated on the basis of extensive spectroscopic analyses. Compound 1 exhibited significant cytotoxicity against human medulloblastoma and colon adenocarcinoma cancer cells.

New verticillane diterpenoids from Cespitularia taeniata

Chemical investigation of Cespitularia taeniata has led to the isolation of three new verticillanes, cespitulins E-G (1-3, resp.). The structures of these compounds were elucidated by spectroscopic analysis, especially HR-MS and 2D-NMR techniques. Compound 1 possesses a rare norverticillane skeleton with two adjacent OH groups at C(5) and C(6), while the seco-compound 2 with an aldehyde group at C(9) results from an unusual bond cleavage between C(9) and C(10). Pharmacological studies revealed that compound 3 exhibited significant activities on superoxide-anion generation and elastase release by human neutrophils in response to FMLP/CB. A plausible biogenetic pathway for compound 2 is also discussed.

Marine natural products

Covering: 2010. Previous review: Nat. Prod. Rep., 2011, 28, 196. This review covers the literature published in 2010 for marine natural products, with 895 citations (590 for the period January to December 2010) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1003 for 2010), together with the relevant biological activities, source organisms and country of origin. Biosynthetic studies, first syntheses, and syntheses that lead to the revision of structures or stereochemistries, have been included.