Schizophrenia (SCZ) is a complex, comprehensible mental condition that creates alienation from reality. SCZ is a mental disease, which is marked by progressive deficits in working memory, attention, and executive functioning. Because the disease’s etiology is unknown, current psychotherapy and pharmacological treatments merely treat symptoms and do not provide a cure. SCZ symptoms include hallucinations, delusions, disorganized behavior, and lack of desire. Long-term use of antipsychotic (antagonists at multiple G-protein-coupled receptors) (mGPCR antagonists) medicines for therapy has negative health consequences and discourages patients from taking regular medication. Ancient herbal therapies are regaining popularity in disease management due to their natural origins, less side effects, and cost-effectiveness. The various types of phytochemicals include alkaloids, glycosides, polyphenols, terpenes and terpenoids, phytosterols, cannabinoids, and carotenoids could be used as mGPCR antagonists. In this review, we documented the possibility of employing natural compounds as an alternative therapy to treat schizophrenia-related symptoms and cognitive impairments.

Chemical exploration of the total extract derived from Epicoccum nigrum Ann-B-2, an endophyte associated with Annona squamosa fruits, afforded two new metabolites, epicoccofuran A (1) and flavimycin C (2), along with four known compounds namely, epicocconigrone A (3), epicoccolide B (4), epicoccone (5) and 4,5,6-trihydroxy-7-methyl-1,3-dihydroisobenzofuran (6). Structures of the isolated compounds were elucidated using extensive 1D and 2D NMR along with HR-ESI–MS. Flavimycin C (2) was isolated as an epimeric mixture of its two diastereomers 2a and 2b. The new compounds 1 and 2 displayed moderate activity against B. subtilis, whereas compounds (2, 3, 5, and 6) showed significant antiproliferative effects against a panel of seven different cancer cell lines with IC₅₀ values ranging from 1.3 to 12 µM.

In this study, we report the isolation of two new meroterpenoids, miniolutelide D (1) and miniolutelide E (13-epi-miniolutelide C) (2), along with two meroterpenoidal analogues (3 and 4) and two phenolic compounds (5 and 6) from the endophytic fungus Talaromyces purpureogenus derived from Punica granatum fruits. Their structures were elucidated using extensive MS, 1D, and 2D NMR spectroscopic analyses as well as by comparing with data in the literature. The absolute configurations of 1 and 2 were determined using TDDFT-ECD calculations. Antimicrobial activity was evaluated. Compound 5 displayed significant activity against methicillin-resistant Staphylococcus aureus strain ATCC 700699 and moderate activity against S. aureus strain ATCC 29213.

Macrozamia communis and its associated endophytic fungi are untapped sources of bioactive metabolites with great potential for medicinal exploitation. Chemical investigation of the mycelial extract derived from an endophytic fungus Penicillium sp. MNP-HS-2 associated with M. communis fruit offered four mycophenolic acid derivatives recognized as previously undescribed natural products (1-4) together with nine known metabolites (5-13). Chemical structures of isolated compounds were determined based on extensive spectroscopic analyses, including 1D/2D NMR and HRESIMS. The absolute stereochemistry of alternatain E (1) was unambiguously established by comparing its experimental and calculated time-dependent density functional theory electronic circular dichroism spectra (TDDFT-ECD). All isolated compounds were assessed for their antimicrobial and cytotoxic activities, where mycophenolic acid methyl ester (7) displayed significant cytotoxic activity against seven different cell lines with IC50 values in the low micromolar to nanomolar range, whereas mycophenolene A (3) exhibited a potent antibacterial activity against Staphylococcus aureus (MIC = 2.1 µg/mL).