Two new phenylpropanoid esters from Bulbophyllum retusiusculum

Ethnobotany, Phytochemistry, Biological Activities, and Health-Promoting Effects of the Genus Bulbophyllum

The genus Bulbophyllum is of scientific interest due to the phytochemical components and diverse biological activities found across species of the genus. Most Bulbophyllum species are epiphytic and located in habitats that range from subtropical dry forests to wet montane cloud forests. In many cultures, the genus Bulbophyllum has a religious, protective, ornamenting, cosmetic, and medicinal role. Detailed investigations into the molecular pharmacological mechanisms and numerous biological effects of Bulbophyllum spp. remain ambiguous. The review focuses on an in-depth discussion of studies containing data on phytochemistry and preclinical pharmacology. Thus, the purpose of this review was to summarize the therapeutic potential of Bulbophyllum spp. biocompounds. Data were collected from several scientific databases such as PubMed and ScienceDirect, other professional websites, and traditional medicine books to obtain the necessary information. Evidence from pharmacological studies has shown that various phytoconstituents in some Bulbophyllum species have different biological health-promoting activities such as antimicrobial, antifungal, antioxidant, anti-inflammatory, anticancer, and neuroprotective. No toxicological effects have been reported to date. Future clinical trials are needed for the clinical confirmation of biological activities proven in preclinical studies. Although orchid species are cultivated for ornamental purposes and have a wide traditional use, the novelty of this review is a summary of biological actions from preclinical studies, thus supporting ethnopharmacological data.

Natural Bioactive Cinnamoyltyramine Alkylamides and Co-Metabolites

Natural products are a vital source for agriculture, medicine, cosmetic and other fields. Among them alkylamides are a broad and expanding group found in at least 33 plant families. Frequently, they possess a simple carbon skeleton architecture but show broad structural variability and important properties such as immunomodulatory, antimicrobial, antiviral, larvicidal, insecticidal and antioxidant properties, amongst others. Despite to these several and promising biological activities, up to today, only two reviews have been published on natural alkylamides. One focuses on their potential pharmacology application and their distribution in the plant kingdom and the other one on the bioactive alkylamides specifically found in Annona spp. The present review is focused on the plant bioactive cinnamoyltyramine alkylamides, which are subject of several works reported in the literature. Furthermore, the co-metabolites isolated from the same natural sources and their biological activities are also reported.

Four new phenanthrene derivatives from Bulbophyllum retusiusculum

Three new dihydrophenanthrenes, retusiusine D (1), retusiusine E (2), retusiusine F (3), and a new phenanthrene retusiusine G (4), together with two known dihydrophenanthrenes 4,7-dihydroxy-2,3-methylenedioxy-9,10-dihydrophenanthrene (5) and epemeranthol-A (6) were isolated from the tubers of Bulbophyllum retusiusculum. Their structures were established on the basis of extensive spectroscopic analyses. Compounds 1 and 2 exhibited potent cytotoxic activities against SMMC-7721 and weak cytotoxic activities against HL-60. Compound 4 showed moderate cytotoxic activity against SMMC-7721 and MCF-7.