Abimael D. Rodriguez

University of Puerto Rico at Río Piedras | UPR-RP · Department of Chemistry

The current 2019–2021 marine pharmacology literature review provides a continuation of previous reviews covering the period 1998 to 2018. Preclinical marine pharmacology research during 2019–2021 was published by researchers in 42 countries and contributed novel mechanism-of-action pharmacology for 171 structurally characterized marine compounds. T...

Plakortinic acids C (1) and D (2), an unseparable pair of endoperoxide polyketides isolated and purified from the symbiotic association of Caribbean Sea sponges Plakortis symbiotica-Xestospongia deweerdtae, underwent in vitro evaluation for antiplasmodial activity against the malaria parasite Plasmodium berghei using a drug luminescence assay. Init...

Kallopterolides A–I (1–9), a family of nine diterpenoids possessing either a cleaved pseudopterane or a severed cembrane skeleton, along with several known compounds were isolated from the Caribbean Sea plume Antillogorgia kallos. The structures and relative configurations of 1–9 were characterized by analysis of HR-MS, IR, UV, and NMR spectroscopi...

The current 2019-2021 marine pharmacology literature review provides a continuation of previous reviews covering the period 1998 to 2018. Preclinical marine pharmacology research during 2019-2021 was published by researchers in 42 countries and contributed novel mechanism of action pharmacology for 171 structurally characterized marine compounds. T...

Gracilioether M (6) and 11,12-dihydrogracilioether M (7), two polyketides with a [2(5H)-furanylidene]ethanoate moiety, along with known plakortone G (9) and its new naturally occurring derivative 9,10-dihydroplakortone G (8), were isolated from the Caribbean marine sponge Plakortis halichondrioides. The structures and absolute configuration of 6, 7...

Two novel dissymmetric diterpenoids, biselisabethoxanes A and B (1 and 2), were isolated from the hexane extracts of the gorgonian coral Pseudopterogorgia elisabethae. Biselisabethoxane A (1) represents the first example of a marine-derived C40 dimer made of two distinct diterpene fragments, whereas biselisabethoxane B (2) is a fused heterodimer st...

The 2018 marine pharmacology literature review represents a continuation of the previous 11 reviews of a series initiated in 1998. Preclinical marine pharmacology research during 2018 was performed by investigators in 44 countries and contributed novel pharmacology for 195 marine compounds. The peer-reviewed marine natural products pharmacology lit...

Plakortinic acids C (3) and D (4), two unprecedented peroxide-polyketides with 7,8-dioxatricyclo[4.2.2.02,5]dec-9-ene scaffold, as well as known biogenetically related congeners, plakortinic acids A (1) and B (2), were isolated from a two-sponge association of Plakortis symbiotica–Xestospongia deweerdtae. Upon chemical derivatization, the structure...

The review of the 2016–2017 marine pharmacology literature was prepared in a manner similar as the 10 prior reviews of this series. Preclinical marine pharmacology research during 2016–2017 assessed 313 marine compounds with novel pharmacology reported by a growing number of investigators from 54 countries. The peer-reviewed literature reported ant...

Briarellins, a subset of C2-C11 cyclized cembranoids, were proposed to contain a C3-C14 ether or lactone bridge, similar to asbestinins. However, the total synthesis of the proposed structure of briarellin J revealed a misassignment. We revisited briarellins, computationally, with the help of a recently developed hybrid DFT/parametric method, DU8+,...

The PI3K/Akt/mTOR kinase pathway is extensively deregulated in human cancers. One critical node under regulation of this signaling axis is eukaryotic initiation factor (eIF) 4F, a complex involved in the control of translation initiation rates. eIF4F-dependent addictions arise during tumor initiation and maintenance due to increased eIF4F activity...

The systematic review of the marine pharmacology literature from 2014 to 2015 was completed in a manner consistent with the 1998–2013 reviews of this series. Research in marine pharmacology during 2014–2015, which was reported by investigators in 43 countries, described novel findings on the preclinical pharmacology of 301 marine compounds. These o...

The discovery of biologically active small molecules requires sifting through large amounts of data to identify unique or unusual arrangements of atoms. Here, we develop, test and evaluate an atom‐based sort to identify novel features of secondary metabolites and demonstrate its use to evaluate novelty in marine microbial and sponge extracts. This...

Die Entdeckung biologisch aktiver Moleküle erfordert das Durchsuchen großer Datenmengen. Hier wird eine atombasierte Sortierung entwickelt, getestet und ausgewertet, um neue Eigenschaften von Sekundärmetaboliten zu identifizieren, was einen wichtigen Schritt hin zur Verwendung autonomer Systeme zur Identifizierung neuer Atomanordnungen innerhalb ei...

Our inability to effectively “drug” targets such as MYC for therapeutic purposes requires the development of new approaches. We report on the implementation of a phenotype-based assay for monitoring MYC expression in multiple myeloma cells. The open reading frame (ORF) encoding an unstable variant of GFP was engineered immediately downstream of the...

Purpose: The DEAD-box RNA helicase eIF4A1 carries out the key enzymatic step of cap-dependent translation initiation and is a well-established target for cancer therapy, but no drug against it has entered evaluation in patients. We identified and characterized a natural compound with broad antitumor activities that emerged from the first target-ba...

The peer-reviewed marine pharmacology literature from 2012 to 2013 was systematically reviewed, consistent with the 1998–2011 reviews of this series. Marine pharmacology research from 2012 to 2013, conducted by scientists from 42 countries in addition to the United States, reported findings on the preclinical pharmacology of 257 marine compounds. T...

Fractionation of the bioactive CHCl3–MeOH (1:1) extracts obtained from two collections of the sponge consortium Plakortis symbiotica–Xestospongia deweerdtae from Puerto Rico provided two new plakinidone analogues, designated as plakinidone B (2) and plakinidone C (3), as well as the known plakinidone (1), plakortolide F (4), and smenothiazole A (5)...

Activation of translation initiation is a common trait of cancer cells. Formation of the heterotrimeric eukaryotic initiation factor F (eIF4F) complex is the rate-limiting step in 5’ m7GpppN cap-dependent translation. This trimeric complex includes the eIF4E cap binding protein, the eIF4G scaffolding protein, and the DEAD box RNA helicase eIF4A. eI...

Plakortinic acids A (2) and B (3), two polyketide endoperoxides with a bicyclo[4.2.0]octene unit, were isolated as minor constituents from the sponge-sponge symbiotic association Plakortis halichondrioides-Xestospongia deweerdtae, along with known epiplakinic acid F (1). The structures of the mixture of two inseparable compounds were determined by...

Herein, we report for the first time the design and linear synthesis of a truncated calyculone H (7) that lacks the telltale isopropyl/isopropylene groups, whereas the 12-membered macrocycle remains intact. Key steps for the framework of target molecule include allylic oxidation using SeO2, Sharpless asymmetric epoxidation, Barbier zinc allylation,...

The absolute configuration of plakinidone (I) is re-assigned as (11S,17R) from the formerly reported (11S,17S) diastereomer.

Recent work by Wu et al. in connection with the first synthesis of the marine natural product plakinidone revealed that the most salient feature of its purported structure, a six-membered perlactone moiety, was in fact a five-membered lactone, i.e. a 3-methyl-4-hydroxy-2(5H)-furanone or tetronic acid ring. With the planar structure of plakinidone c...

The novel fatty acids (2R,5Z,9Z)-2-methoxy-25-methyl-5,9-hexacosadienoic acid (1a) and (2R,5Z,9Z)-2-methoxy-24-methyl-5,9-hexacosadienoic acid (1b) were isolated in 80 % purity from the Caribbean sponge Asteropus niger by chloroform/methanol extraction followed by solvent partitioning and silica gel column chromatography. The compounds were charact...

The marine natural product (-)-8,15-diisocyano-11(20)-amphilectene (1), isolated from the Caribbean sponge Svenzea flava, was used as scaffold to synthetize five new products, all of which were tested against laboratory strains of Plasmodium falciparum and Mycobacterium tuberculosis H37Rv. The scaffold contains two isocyanide units that are amenabl...

Bioassay-guided fractionation of the Caribbean sponge Svenzea flava collected near Mona Island, off the west coast of Puerto Rico, led to the isolation of two isocyanide amphilectane-type diterpenes named monamphilectines B and C (2 and 3). Attached to the backbone of each of these compounds is the first α-substituted monocyclic β-lactam ring to be...

Three new cembrane-based diterpenes possessing the rare 3,14-oxa-bridged moiety were isolated from the hexane extract of a southwestern Caribbean gorgonian octocoral, Eunicea pinta, together with seven known cembranoid diterpenes. The structures of pintoxolanes A–C (1–3, resp.), including their relative configurations, were deduced from spectroscop...

A new investigation of the active sponge extracts of Prosuberites laughlini collected off the West coast of Puerto Rico has yielded three new cyclic heptapeptides, namely euryjanicins E (1)-G (3), containing multiple phenylalanine and proline residues. In CDCl3 solution, each euryjanicin F (2) and G (3) exists as an inseparable complex mixture of c...

A new regular diterpene possessing an unusual 1,6-anti-3-methylcyclohex-2-en-1-ol ring system, dactyloditerpenol acetate (1), has been extracted from the tropical sea hare Aplysia dactylomela and its stereostructure elucidated by spectroscopic methods. The absolute configuration of 1 was determined as 1S, 6S, 7R, 10S, and 11R by application of Kish...

Two new natural products, 3 and 4, and their predecessor 7-isocyanoisoneoamphilecta-1(14),15-diene (2), of the rare isoneoamphilectane-class of marine diterpenes, along with the known amphilectane diterpenes 6-8, were isolated from the n-hexane extract of the marine sponge Svenzea flava collected at Great Inagua Island, Bahamas. The molecular struc...

The peer-reviewed marine pharmacology literature from 2009 to 2011 is presented in this review, following the format used in the 1998-2008 reviews of this series. The pharmacology of structurally-characterized compounds isolated from marine animals, algae, fungi and bacteria is discussed in a comprehensive manner. Antibacterial, antifungal, antipro...

Natural products have a venerable history of, and enduring potential for the discovery of useful biological activity. To fully exploit this, the development of chemical methodology that can functionalize unique sites within these complex structures is highly desirable. Here, we describe the use of rhodium(II)-catalysed C-H amination reactions devel...

The Caribbean gorgonian Briareum asbestinum has been shown to contain representatives from three skeletal classes, asbestinins, briareins, and eunicellins. The structural diversity of the diterpenoids isolated suggest a common biosynthetic pathway. Briarellins -A (1), -B (3), -C (5), and -D (6) are members of a new class of tetracyclic diterpenoids...

The Caribbean mollusk Dolabrifera dolabrifera from Puerto Rico contains two new propionate-derived metabolites, dolabriferols B and C (2 and 3), in addition to the known compound dolabriferol (1). The structures of dolabriferols B (2) and C (3) were established by comparison of their spectral data with those of 1, and the absolute configuration of...

The title compound, C26H42ClNO2, is a 3β-chloro steroid with a Weinreb amide at the C-24 position. The two cyclo­hexane and the cyclo­hexene rings adopt chair and boat conformations, respectively. The cyclo­pentane ring has an envelope conformation.

Two new diterpenes having the rare cubitane skeleton were isolated from a southwestern Caribbean gorgonian coral of the genus Eunicea. The structures of the new metabolites, as well as those of three known cubitanes were elucidated by extensive spectroscopic analysis. One compound showed significant in vitro cytotoxic activity against a National Ca...

In the crystal structure of kallolide A acetate pyrazoline [systematic name: 7-methyl-16-oxo-4,10-bis­(prop-1-en-2-yl)-17,18-dioxa-14,15-diaza­tetra­cyclo­[9.4.2.16,9.01,12]octa­deca-6,8,14-trien-5-yl acetate], C23H28N2O5, there is a 12-member­ed carbon macrocyclic structure. In addition, there is a tris­ubstituted furan ring, an approximately plan...

The effects of five Hymeniacidon sp. amphilectane metabolites (1-5) and two semi-synthetic analogs (6 and 7) on thromboxane B(2) (TXB(2)) and superoxide anion (O(2)(-)) generation from Escherichia coli LPS-activated rat brain microglia were investigated. All Hymeniacidon sp. metabolites and analogs potently inhibited TXB(2) (IC(50)=0.20-4.69μM) wit...

A bidirectional affinity system has been developed for the identification of cancer-related natural products and their biological targets. Aplysqualenol A is thus selectively identified as a ligand of the dynein light chain. The use of forward and reverse affinity methods suggests that both small-molecule isolation and target identification can be...

New approaches are vital to the development of marine natural products (MNP) as therapeutic leads. One of the more time consuming aspects of MNP research arises in the connection between structure and function. Here, we describe an isolation protocol that adapts tumor cell proteomes as a vehicle for MNP isolation therein uniting structural and func...

The peer-reviewed marine pharmacology literature in 2007-8 is covered in this review, which follows a similar format to the previous 1998-2006 reviews of this series. The preclinical pharmacology of structurally characterized marine compounds isolated from marine animals, algae, fungi and bacteria is discussed in a comprehensive manner. Antibacteri...

Thirteen new cembranolide diterpenoids, uprolides 3–15, have been isolated from the Caribbean gorgonian Euniceamammosa collected off the West coast of Puerto Rico. Several known metabolites, such as eupalmerin acetate (1) and eupalmerin (2), were also isolated from the same organism. The structures of the new compounds, which also showed modest in...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A recent chemical investigation of the hexane extract of a Colombian specimen of Pseudopterogorgia elisabethae (Bayer) has led to the isolation or ileabethin (1). This novel diterpene possesses a previously undescribed carbon skeleton which appears, to be biobynthetically related to the serrulatane (biflorane) skeleton. The structure of 1 was eluci...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A new tetracyclic bis-piperidine alkaloid, neopetrosiamine A (1), has been extracted from the marine sponge Neopetrosiaproxima collected off the west coast of Puerto Rico. The structure of compound 1 was elucidated by analysis of spectroscopic data coupled with careful comparisons of its (1)H and (13)C NMR data with those of a well-known 3-alkylbis...

Two new five-membered-ring polyketide endoperoxides, epiplakinic acid F methyl ester (1) and epiplakinidioic acid (3), and a peroxide-lactone, plakortolide J (2), were isolated from the Puerto Rican sponge Plakortis halichondrioides, along with two previously reported cyclic peroxides, 4 and 5. The structures of the new metabolites were determined...

The total synthesis of the originally proposed structure of briarellin J is reported in 15 steps from a known compound and in 23 steps from readily available materials. Key reactions include an exo-selective intramolecular Diels-Alder and a substrate-controlled hydroboration. Discrepancies in the spectroscopic data of the synthetic and natural mate...

Monamphilectine A (1), a new diterpenoid β-lactam alkaloid showing potent antimalarial activity, was isolated in milligram quantities following bioassay-directed extraction of a Puerto Rican marine sponge Hymeniacidon sp. Its structure, established by interpretation of spectral data, was confirmed unequivocally by chemical interconversion and compa...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Five new eunicellin-type diterpenoids, briarellins E-I, along with several known diterpenoids of the asbestinane, briarane and eunicellane classes, were isolated from the Caribbean gorgonian octocoral Briareum asbestinum collected in Puerto Rico. The structures of these compounds were established on the basis of spectroscopic evidence.

Neuroinflammation appears to involve release of thromboxane B 2 (TXB 2 ) and superoxide anion (O 2 ⁻ ) by brain microglia (BMG). The purpose of this investigation was to determine the effect of five Hymeniacidon sp. amphilectane metabolites (HsH2.6, HsH1.11, HsH2.13, HsH2.29_456, and HsH2.11.X7.3) and two semi‐synthetic analogs (HsH1.11x and HsH1.1...

Ten new diterpenes, 1-10, having a dolabellane skeleton were isolated from a Colombian gorgonian coral of the genus Eunicea. Their structures, as well as those of known compounds 11-18, were determined on the basis of spectroscopic analysis and, in some instances, by chemical conversion and X-ray crystallographic analysis. The absolute structure of...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

This chapter intends to provide a comprehensive review of the natural products chemistry of gorgonian octocorals of the genus Pseudopterogorgia from the beginning of 1968 to early 2009. The primary aim is to include all the marine natural products reported from this group of marine animals and to provide information regarding all of the gorgonian s...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

In addition to the previously reported terpenoids 1 and 2, a chemical study of the hexane extracts of Pseudopterogorgia elisabethae led to the isolation of two novel skeletal lactones 3 and 4. Their complete structures were established by interpretation of spectral data.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The novel bromotriterpene polyethers aplysqualenol A (1) and aplysqualenol B (2) have been isolated from the Caribbean sea slug Aplysia dactylomela collected in Puerto Rico, and their structures and relative configurational assignments established from spectroscopic data aided by quantum mechanical calculations of NMR chemical shifts. Although both...

Two novel tricyclic diterpenes, corallolides A (1) and B (2), were isolated from the chloroform extract of the Caribbean gorgonian octocoral Pseudopterogorgia bipinnata collected near Providencia Island, Colombia. Their structures are based on a previously undescribed bicyclo[9.2.1]tetradecane ring system that was established through detailed spect...

The chromatographic separation of a relatively small fraction obtained from the hexane extract of the gorgonian octocoral Pseudopterogorgia elisabethae (Bayer, 1961) collected in San Andres Island, Colombia has led to the discovery of four members of an unusual family of bisditerpene metabolites named biselisabethoxanes A-D. The isolation, structur...

Marine sponges, especially from tropical oceans, represent the most prolific source of structurally novel marine natural products with diverse pharmacological actions. As part of our ongoing search to find new natural products with anticancer activity from marine organisms from off shore Puerto Rico, we studied the Caribbean marine sponge Prosuberi...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A marine metabolite based on a previously undescribed carbon skeleton, aberrarone (1), is reported as a natural product from the Caribbean sea whip, Pseudopterogorgia elisabethae. The molecular structure of the crystalline metabolite was established by spectral analysis and subsequently confirmed by X-ray crystallographic analysis. Aberrarone shows...

Three new cyclic peptides, euryjanicins B (2), C (3), and D (4), have been isolated from the Puerto Rican marine sponge Prosuberites laughlini, and the structures were elucidated by chemical degradation, ESIMS/MS, and extensive 2D NMR methods. When tested against the National Cancer Institute 60 tumor cell line panel, all of the purified isolates d...