Components from the Leaves and Twigs of Mangrove Lumnitzera racemosa with Anti-Angiogenic and Anti-Inflammatory Effects

Chemical composition and antimicrobial activity of the essential oil of Lumnitzera racemosa Willd

Lumnitzera racemosa Willd is a medicinal species that supports the treatment of certain conditions. This is the first study on the chemical composition and antimicrobial activities of the essential oil from Lumnitzera racemosa Willd bark. This essential oil was extracted by the hydrodistillation method and analysed by gas chromatography (GC), and gas chromatography coupled with mass spectrometry (GC-MS). The results showed that the essential oil contains twenty-four compounds, the main of which are palmitic acid, nonacosane, and heptacosane. The antimicrobial activities of the essential oil against Pseudomonas aeruginosa, and Staphylococcus aureus had inhibition zones ranging from approximately 8.4-17.5 mm. This study has enhanced the understanding of the composition, and antimicrobial activities of L. racemosa and expanded its potential applications in the medical field.

Immunomodulatory Compounds from the Sea: From the Origins to a Modern Marine Pharmacopoeia

From sea shores to the abysses of the deep ocean, marine ecosystems have provided humanity with valuable medicinal resources. The use of marine organisms is discussed in ancient pharmacopoeias of different times and geographic regions and is still deeply rooted in traditional medicine. Thanks to present-day, large-scale bioprospecting and rigorous screening for bioactive metabolites, the ocean is coming back as an untapped resource of natural compounds with therapeutic potential. This renewed interest in marine drugs is propelled by a burgeoning research field investigating the molecular mechanisms by which newly identified compounds intervene in the pathophysiology of human diseases. Of great clinical relevance are molecules endowed with anti-inflammatory and immunomodulatory properties with emerging applications in the management of chronic inflammatory disorders, autoimmune diseases, and cancer. Here, we review the historical development of marine pharmacology in the Eastern and Western worlds and describe the status of marine drug discovery. Finally, we discuss the importance of conducting sustainable exploitation of marine resources through biotechnology.

Challenging Structure Elucidation of Lumnitzeralactone, an Ellagic Acid Derivative from the Mangrove Lumnitzera racemosa

The previously undescribed natural product lumnitzeralactone (1), which represents a derivative of ellagic acid, was isolated from the anti-bacterial extract of the Indonesian mangrove species Lumnitzera racemosa Willd. The structure of lumnitzeralactone (1), a proton-deficient and highly challenging condensed aromatic ring system, was unambiguously elucidated by extensive spectroscopic analyses involving high-resolution mass spectrometry (HRMS), 1D ¹H and ¹³C nuclear magnetic resonance spectroscopy (NMR), and 2D NMR (including 1,1-ADEQUATE and 1,n-ADEQUATE). Determination of the structure was supported by computer-assisted structure elucidation (CASE system applying ACD-SE), density functional theory (DFT) calculations, and a two-step chemical synthesis. Possible biosynthetic pathways involving mangrove-associated fungi have been suggested.

Biological Secondary Metabolites from the Lumnitzera littorea-Derived Fungus Penicillium oxalicum HLLG-13

Five new compounds, including two cyclopiane diterpenes conidiogenones J and K (1-2), a steroid andrastin H (5), an alkaloid (Z)-4-(5-acetoxy-N-hydroxy-3-methylpent-2-enamido) butanoate (6), and an aliphatic acid (Z)-5-acetoxy-3-methylpent-2-enoic acid (7), together with ten known compounds (3-4 and 8-15) were isolated from the EtOAc extract of the fermentation broth of the Lumnitzera littorea-derived fungus Penicillium oxalicum HLLG-13. Their structures were elucidated by 1D, 2D NMR, and HR-ESI-MS spectral analyses. The absolute configurations of 1, 2, 5, and 8 were determined by quantum chemical electronic circular dichroism (ECD) calculations, and the absolute configuration of 8 was determined for the first time. Compound 15 was a new natural product, and its NMR data were reported for the first time. Compounds 5 and 9-14 exhibited antibacterial activities against Staphylococcus epidermidis and Candida albicans, with MIC values ranging from 6.25 to 25 μg/ mL. Compounds 1-6 and 9-14 showed significant growth inhibition activities against newly hatched Helicoverpa armigera Hubner larvae, with IC₅₀ values ranging from 50 to 200 μg/mL.

Therapeutic potential and ethnopharmacology of dominant mangroves of Bhitarkanika National Park, Odisha, India

Bhitarkanika National Park, is the second largest contiguous mangrove forest of India. Despite being one of the most diverse mangrove habitations of India, its phytoresources has not been adequately explored for their therapeutic potentials. However, the ethnopharmacological practices are comparatively lower than the other mangrove regions of India and Southeast Asia. Ageold ethnobotanical informations have always led biologists, chemists and pharmacists in quenching the demands of therapeutically important phytocompounds and their possible use for the betterment of mankind. The present review is aimed to congregate information on the therapeutic potential and ethnopharmacology of nine dominant mangrove species of the National Park. It will manifest the demand of social awareness among the mangrove dwellers to promote uses of folklore medicine as a complementary step to strengthen community health.

Analysis of Unusual Sulfated Constituents and Anti-infective Properties of Two Indonesian Mangroves, Lumnitzera littorea and Lumnitzera racemosa (Combretaceae)

Lumnitzera littorea and Lumnitzera racemosa are mangrove species distributed widely along the Indonesian coasts. Besides their ecological importance, both are of interest owing to their wealth of natural products, some of which constitute potential sources for medicinal applications. We aimed to discover and characterize new anti-infective compounds, based on population-level sampling of both species from across the Indonesian Archipelago. Root metabolites were investigated by TLC, hyphenated LC-MS/MS and isolation, the internal transcribed spacer (ITS) region of rDNA was used for genetic characterization. Phytochemical characterization of both species revealed an unusual diversity in sulfated constituents with 3,3’,4’-tri-O-methyl-ellagic acid 4-sulfate representing the major compound in most samples. None of these compounds was previously reported for mangroves. Chemophenetic comparison of L. racemosa populations from different localities provided evolutionary information, as supported by molecular phylogenetic evidence. Samples of both species from particular locations exhibited anti-bacterial potential (Southern Nias Island and East Java against Gram-negative bacteria, Halmahera and Ternate Island against Gram-positive bacteria). In conclusion, Lumnitzera roots from natural mangrove stands represent a promising source for sulfated ellagic acid derivatives and further sulfur containing plant metabolites with potential human health benefits.

Marine natural products

This review covers the literature published between January and December in 2018 for marine natural products (MNPs), with 717 citations (706 for the period January to December 2018) 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 (1554 in 469 papers for 2018), together with the relevant biological activities, source organisms and country of origin. Reviews, biosynthetic studies, first syntheses, and syntheses that led to the revision of structures or stereochemistries, have been included. The proportion of MNPs assigned absolute configuration over the last decade is also surveyed.