Plant-derived antimicrobials to fight against multi-drug-resistant human pathogens

Antibiotic resistance is becoming a pivotal concern for public health that has accelerated the search for new antimicrobial molecules from nature. Numbers of human pathogens have inevitably evolved to become resistant to various currently available drugs causing considerable mortality and morbidity worldwide. It is apparent that novel antibiotics are urgently warranted to combat these life-threatening pathogens. In recent years, there have been an increasing number of studies to discover new bioactive compounds from plant origin with the hope to control antibiotic-resistant bacteria. This review attempts to focus and record the plant-derived compounds and plant extracts against multi-drug-resistant (MDR) pathogens including methicillin-resistant Staphylococcus aureus (MRSA), MDR-Mycobacterium tuberculosis and malarial parasites Plasmodium spp. reported between 2005 and 2015. During this period, a total of 110 purified compounds and 60 plant extracts were obtained from 112 different plants. The plants reviewed in this study belong to 70 different families reported from 36 countries around the world. The present review also discusses the drug resistance in bacteria and emphasizes the urge for new drugs

Aurantoside K, a New Antifungal Tetramic Acid Glycoside from a Fijian Marine Sponge of the Genus Melophlus

A new tetramic acid glycoside, aurantoside K, was isolated from a marine sponge belonging to the genus Melophlus. The structure of the compound was elucidated on the basis of spectroscopic analysis (1H NMR, 1H–1H COSY, HSQC, and HMBC, as well as high-resolution ESILCMS). Aurantoside K did not show any significant activity in antimalarial, antibacterial, or HCT-116 cytotoxicity assays, but exhibited a wide spectrum of antifungal activity against wild type Candida albicans, amphotericin-resistant C. albicans, Cryptococcus neoformans, Aspergillus niger, Penicillium sp., Rhizopus sporangia and Sordaria sp

Five new species of Sarcophyton (Coelenterata: Octocorallia) from the Fiji Islands

This paper describes five new species of the soft coral genus Sarcophyton which were identified by their morphological characters (colony form and sclerite shape). The five species have been named: S. aalbersbergi sp. nov., S. aldersladei sp. nov., S. alexanderi sp. nov., S. skeltoni sp. nov and S. soapiae sp. nov. For the first time it is documented that there is a Sarcophyton species that does not have sclerites in the interior of the disc

Antimicrobial and cytotoxic activities of marine plants and invertebrates from the coast of Espirito Santo in Vanuatu

Marine invertebrates and algae collected off the coast of Espirito Santo in Vanuatu were investigated for antimicrobial and cytotoxic activities. The combined crude methanol-dichloromethane extracts from 52 sponges, 5 algae, 17 soft corals (cnidaria) and 5 other samples of various marine invertebrates were screened for cytotoxicity, antibacterial and antifungal properties. The cytotoxicity of the samples was determined using a brine shrimp lethality test and, notably, 78% of the invertebrate and algae samples showed cytotoxic activity against brine shrimps with the sponge Crella spinulata displaying the strongest activity. Antimicrobial activity was determined against three resistant bacterial strains and two fungal strains. A total of 42% of the samples tested showed antimicrobial activity against at least one of the five strains. The most potent antibacterial activities were recorded for the sponges Lamellodysidea herbacea, Phyllospongia sp., a sponge in the order Halichondrida and Hippospongia metachromia. A Theonella sp. sponge displayed the strongest antifungal activity

Papuamides E and F, cytotoxic depsipeptides from the marine sponge

Two known papuamides C (1) and D (2) together with two new depsipeptides, papuamides E (3) and F (4), were isolated from an undescribed sponge of the genus Melophlus collected in the Solomon Islands. The planar structures of the compounds were elucidated on the basis of spectroscopic studies. Papuamides C–F (1–4) showed cytotoxicity against brine shrimp with LD50 values between 92 and 106 μg/mL

Papuamides E and F, cytotoxic depsipeptides from the marine sponge Melophlus sp.

Two known papuamides C (1) and D (2) together with two new depsipeptides, papuamides E (3) and F (4), were isolated from an undescribed sponge of the genus Melophlus collected in the Solomon Islands. The planar structures of the compounds were elucidated on the basis of spectroscopic studies. Papuamides C-F (1-4) showed cytotoxicity against brine shrimp with LD values between 92 and 106 μg/mL

Patterns of Substrate Bioerosion by Excavating Sponges From the Southwest and Central Pacific Ocean

Reef rubble from a number of locations in the southwest and central Pacific (Fiji, Kiribati, Solomon Islands) was surveyed for its level of infestation with bioeroding sponges. The assessment was performed by random sampling of reef rubble in shallow water ranging from intertidal to subtidal down to 15 m of water depth. It was found that essentially four styles of bioerosion prevailed: 1) small cavities with roundish cross sections commonly produced by Pione spp. and Cliona cf. macgeachii Holmes; 2) large cavities in the order of cm-size are for example produced by Aka spp., Cliothosa spp., Cliona cf. janitrix Topsent, Cliona cf. ensifera Sollas, and others; 3) multiple etchings which can degrade the interior of coral rubble on a scale of a few cm in diameter are typically produced by both, Cliona orientalis and C. celata species complexes; and 4) large hadromerid sponges are capable of eroding into solid reef rock and produce silt-, sand-, and pebble-sized fragments. Observed was the activity of Spheciospongia solida (Ridley & Dendy) and S. cf. inconstans var. digitata Dendy. These large clionaid sponges are the most efficient eroders on the reef. Species of Pione are abundant at all sites from intertidal to subtidal, and although they are weak bioeroders, they may be the most destructive by number

Ostreobium quekettii (Ostreobiaceae: Chlorophyceae) invading the barnacle Acasta sp. (Pendunculata: Acastinae), endozoic in the octocoral rumphella suffruticosa (Alcyonacea: Gorgoniidae) from Fiji, south pacific

he eukaryotic alga Ostreobium quekettii (Ostreobiaceae: Chlorophyceae) is reported from Fiji for the first time. It is found creeping over the calcareous plates of dead specimens of species of a barnacle genus Acasta (Pendunculata: Acastinae), which was endozoic in the gorgonian Rumphella suffruticosa. The barnacles are lodged in cavities in the coenenchyme of the gorgonian, mostly in the vicinity of colonial branching points. There is little external evidence of the location of the barnacles where the gorgonian tissue is thick, but where it is thin, prominent galls are visible. There is no evidence that the barnacle or algal association causes stress to the host, which was otherwise healthy in appearance. The presence of the algae would appear to be associated with the occurrence of the barnacles