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The community-based mentorship program MPOWIR (Mentoring Physical Oceanography Women+ to Increase Retention) supports late-stage graduate students and early-career professionals who identify as women or non-binary genders. Its participants engage in mentorship training and professional development, facilitate group mentoring, and draw attention to barriers women and non-binary genders face in physical oceanography. MPOWIR was created to increase the retention of women in physical oceanography in early career stages but has unexpectedly benefited the MPOWIR community beyond graduate students and early career professionals. Senior leaders participating as mentors in MPOWIR report a renewed sense of purpose, new research collaborations, a chance to challenge their own biases, learning new ways to support mentees at their home institutions, awareness about career trajectories outside academia, and a stronger sense of community amid researchers who often felt isolated due to lack of diversity in their ranks. As they guide and inspire the next generation, mentors reflect on their own career struggles and advise on changes that will create a more equitable future for the discipline. This paper highlights the impacts of MPOWIR mentorship on senior leaders in physical oceanography and demonstrates that mentorship is a two-way exchange that energizes and inspires all participants to become active agents of change. It concludes with reflections on how institutions and organizations can facilitate effective mentoring and remove barriers to the professional development of senior leaders in mentoring roles.

Two new chlorinated bis-indole alkaloids, dionemycin (1) and 6-OMe-7′,7″-dichorochromopyrrolic acid (2), along with seven known analogs 3–9, were isolated from the deep-sea derived Streptomyces sp. SCSIO 11791. Their structures were elucidated by extensive HRESIMS, and 1D and 2D NMR data analysis. In vitro antibacterial and cytotoxic assays revealed that, compound 1, shows anti-staphylococcal activity with an MIC range of 1–2 μg/mL against six clinic strains of methicillin-resistant Staphylococcus aureus (MRSA) isolated from human and pig. Additionally, compound 1 displayed cytotoxic activity against human cancer cell lines NCI-H460, MDA-MB-231, HCT-116, HepG2, and noncancerous MCF10A with an IC50 range of 3.1–11.2 μM. Analysis of the structure-activity relationship reveals that the chlorine atom at C-6″ could be pivotal for conferring their bioactivities, thus providing hints on chemical modifications on bis-indole alkaloid scaffold in drug design.

The marine-derived fungus Trichoderma sp. TPU199 (cf. Trichodermabrevicompactum) produces pretrichodermamide A (1) and gliovirin (2), which possess a rare type of epipolythiodiketopiperazine (ETP) structure with a disulfide bridge between the α- and β-positions of two amino acid residues. We previously reported that this strain gave the halogenated ETPs, DC1149B (4), DC1149R (6), and iododithiobrevamide (7), when fermented with sodium halides (NaCl, NaBr, and NaI). Further analyses of the metabolites obtained under NaI-containing culture conditions resulted in the isolation of two new ETP derivatives (11 and 12) and three new trichothecene sesquiterpenes (13–15). The structures of 11 and 12, including their absolute configurations, were elucidated based on spectroscopic data for 11 and 12 and comparisons with those for 1 and related compounds, revealing that 11 was an epimer of 1 at the C-5 position and 12 was a trithio-derivative of 11. The structures of 13–15 were established by analyzing their 1D and 2D NMR data. The absolute configurations of 13–15 were assigned by comparing their experimental electronic circular dichroism (ECD) spectra with the calculated ECD spectrum of 13.

The conspicuous bright golden to orange-reddish coloration of species of the basidiomycete genus Laetiporus is a hallmark feature of their fruiting bodies, known among mushroom hunters as the “chicken of the woods”. This report describes the identification of an eight-domain mono-modular highly reducing polyketide synthase as sole enzyme necessary for laetiporic acid biosynthesis. Heterologous pathway reconstitution in both Aspergillus nidulans and Aspergillus niger verified that LpaA functions as a multi-chain length polyene synthase, which produces a cocktail of laetiporic acids with a methyl-branched C26–C32 main chain. Laetiporic acids show a marked antifungal activity on Aspergillus protoplasts. Given the multiple products of a single biosynthesis enzyme, our work underscores the diversity-oriented character of basidiomycete natural product biosynthesis.

Iseolides A–C (1–3), three new glycosylated macrolides, were identified from the culture extract of Streptomyces sp. DC4-5 isolated from a stony coral Dendrophyllia. Extensive analysis of one- and two-dimensional NMR data, coupled with MS/MS analytical data, revealed that iseolides are new congeners of 36-membered macrolides, PM100117 and PM100118, previously reported from a marine-derived Streptomyces. Iseolides showed potent antifungal activity against a plant pathogen Glomerella cingulata and human pathogens Candida albicans and Trichophyton rubrum with MIC in the range of 0.19–6.25 μg/mL.

A new diketopiperazine-like compound, designated protuboxepin K (1), was isolated together with the known structurally related protuboxepin A (2) from culture broth of the marine-derived fungal strain Aspergillus sp. BFM-0085 isolated from a sediment sample of Tokyo Bay. The structure of protuboxepin K was elucidated by spectroscopic data, including 1D and 2D NMR. Compounds 1 and 2 inhibited bone morphogenetic protein (BMP)-induced alkaline phosphatase activity with IC50 values of 4.7 and 25.2 μM, respectively, in mutant BMP receptor-carrying C2C12(R206H) cells.

Lascivol was identified as the bitter compound in two Tricholoma species, T. aestuans and T. virgatum, and was previously isolated from the European mushroom T. lascivum. The structure of lascivol was previously solved by X-ray crystallographical analysis but its stereochemistry at C3 remained ambiguous. We thus re-examined the absolute configuration of C3 bearing a hydroxy group using the modified Mosher’s method.

Due its unique structure and its reported potent antifungal activity, the marine polyketide hippolachnin A (1) has attracted much attention in the synthetic community. Herein, we describe the development of a concise, diversifiable and scalable synthesis of the racemic natural product, which serves as a platform for the generation of bioactive analogues. Biological testing of our synthetic material did not confirm the reported antifungal activity of hippolachnin A but unraveled moderate activity against nematodes and microbes.

Habitat connectivity and trophic shifts during the lifetime of an individual fish are important determinants of fish population growth and persistence, yet remain little understood for many species. We investigated whether insights into individual lifetime migration, trophic position (TP) and environmental nitrogen dynamics could be achieved using compound-specific nitrogen isotope analysis of otolith proteinogenic amino acids (AAs). By comparing acoupa weakfish Cynoscion acoupa otoliths and muscle tissue from the monsoonal Amazon area in Pará with otoliths from semi-arid Rio Grande do Norte (RGN), Brazil, this study illustrates estuarine to coastal shelf habitat use and trophic ecology during juvenile and adult stage growth. Muscle tissue and otoliths gave comparable TPs for both life stages, while weighted mean δ15N values of all source AAs differed between tissues. These differences reflected large seasonal and spatial changes in nitrogen biogeochemical cycles and anthropogenic nitrogen influences from the Amazon River onto the coastal shelf of Pará. AA δ15N values of fish otoliths from the Pará region indicated changes in TP and sources of nitrogen between life stages, whereas analysis of fish otoliths from the RGN region indicated similarities in individual TP and sources of nitrogen through ontogeny. However, in both areas, individual adult TP ranged between 3 and 4, whereas juvenile TP remained around 2.8 to 3.0 in Pará and RGN, respectively. Since otoliths preserve a record of baseline δ15N values over the lifetime of individual fish it may be possible to infer migration and TP across pre historic ecosystems from AA isotopic analysis of an cient otoliths.

Crude extracts of the marine sponge Chelonaplysilla sp. collected in Samoa, that were obtained from the NCI Open Repository (NCS 21903), inhibited Mycobacterium tuberculosis growth. Assay-guided fractionation of the extract led to the isolation and structural elucidation of the known diterpenoid macfarlandin D (1) and three new diterpenoids macfarlandins F (2), G (3), and H (4). Macfarlandin D (1) exhibited potent antimicrobial activity against M. tuberculosis with an MIC of 1.2 ± 0.4 µg mL−1. Macfarlandins F (2), G (3), and H (4) exhibited significantly weaker antitubercular activities, revealing SAR for the macfarlandin antitubercular pharmacophore. The structures of compounds 2, 3, and 4 were elucidated via detailed analysis of NMR and MS data.