Myrrhanolide D and Myrrhasin A, New Germacrane-Type Sesquiterpenoids from the Resin ofCommiphora opobalsamum

Medicinal plant resin natural products: structural diversity and biological activities

Covering: up to the mid of 2023Plants secrete defense resins rich in small-molecule natural products under abiotic and biotic stresses. This comprehensive review encompasses the literature published up to mid-2023 on medicinal plant resin natural products from six main contributor genera, featuring 275 citations that refer to 1115 structurally diverse compounds. The scope of this review extends to include essential information such as the racemic nature of metabolites found in different species of plant resins, source of resins, and revised structures. Additionally, we carefully analyze the reported biological activities of resins, organizing them based on the their structures. The findings offer important insights into the relationship between their structure and activity. Furthermore, this detailed examination can be valuable for researchers and scientists in the field of medicinal plant resin natural products and will promote continued exploration and progress in this area.

Exploring the Anticancer Potential of Premna resinosa (Hochst.) Leaf Surface Extract: Discovering New Diterpenes as Heat Shock Protein 70 (Hsp70) Binding Agents

Premna, a genus consisting of approximately 200 species, predominantly thrives in tropical and subtropical areas. Many of these species have been utilized in ethnopharmacology for diverse medicinal applications. In Saudi Arabia, Premna resinosa (Hochst.) Schauer (Lamiaceae) grows wildly, and its slightly viscid leaves are attributed to the production of leaf accession. In this study, we aimed to extract the surface accession from fresh leaves using dichloromethane to evaluate the anticancer potential. The plant exudate yielded two previously unknown labdane diterpenes, Premnaresone A and B, in addition to three already described congeners and four known flavonoids. The isolation process was accomplished using a combination of silica gel column chromatography and semi-preparative HPLC, the structures of which were identified by NMR and HRESIMS analyses and a comparison with the literature data of associated compounds. Furthermore, we employed a density functional theory (DFT)/NMR approach to suggest the relative configuration of different compounds. Consequently, we investigated the possibility of developing new chaperone inhibitors by subjecting diterpenes 1-5 to a Surface Plasmon Resonance-screening, based on the knowledge that oridonin, a diterpene, interacts with Heat Shock Protein 70 (Hsp70) 1A in cancer cells. Additionally, we studied the anti-proliferative activity of compounds 1-5 on human Jurkat (human T-cell lymphoma) and HeLa (epithelial carcinoma) cell lines, where diterpene 3 exhibited activity in Jurkat cell lines after 48 h, with an IC₅₀ of 15.21 ± 1.0 µM. Molecular docking and dynamic simulations revealed a robust interaction between compound 3 and Hsp70 key residues.

Forgotten Perfumery Plants - Part I: Balm of Judea

Perfumes have always been products of great importance, mainly composed of natural, valuable and vegetal raw materials. Today, some of them have completely disappeared in perfumery, even though they are part of our cultural heritage and were commonly used in the past. Balm of Judea is one of the most noble, rare and fascinating ingredient long used in perfumery and medicine, that is missing today. After years of research, we collected a resin and an essential oil (steam distillation of fresh aerial parts) from Commiphora gileadensis (L.) C.Chr. native from Saudi Arabia and cultivated in Israel. The aims of this study were to i) identify the main reasons of the loss of the balm of Judea, ii) characterize the volatile composition of the resin and the essential oil and iii) evaluate their olfactory profile and assess their biological activity. Eighty-three compounds were identified in the resin, by a combination of GC-MS and GC/FID techniques, using direct injection and HS-SPME. α-Pinene (24.0 %), sabinene (43.8 %), β-pinene (6.3 %) and cymene (3.6 %) were the main identified compounds, giving an intense, terpenic and lemony smell to the resin. Anti-inflammatory, wound-healing and whitening activities were highlighted. Sabinene (22.7 %), terpinen-4-ol (18.7 %), α-pinene (14.4 %) and cymene (13.6 %) were identified as the main components of the essential oil, giving a spicy, woody and lemony fragrance. Anti-inflammatory and whitening activities were emphasized.

Biological activity of natural sesquiterpenoids containing a gem-dimethylcyclopropane unit

The biological activity of sesquiterpenes containing the gem-dimethylcyclopropane unit is described.