Incensfuran: isolation, X-ray crystal structure and absolute configuration by means of chiroptical studies in solution and solid state

Abstract

A new cembrane diterpene named incensfuran (1), biogenetically derived from incensole (2), was isolated from crude extracts of the Boswellia papyrifera Hochst.

Cembrane-type diterpenoids from the gum resin of Boswellia carterii and their biological activities

“…The IR spectrum suggested the absorption bands for hydroxy (3476 cm À1 ) and ester carbonyl (1736 cm À1 ) groups. Its 1 H NMR data (Table 1) 13 C NMR and HSQC spectra showed signals of ve methyls, ve methylenes, six methines including one olenic methine at d C 125.3 (C-9), four oxymethines at d C 59.2 (C-3), 53.6 (C-6), 56.1 (C-7), 80.9 (C-11), and four quaternary carbons including three oxygenated tertiary carbons at d C 89.0 (C-1), 57.7 (C-4), and 83.8 (C-12), and one quaternary olenic carbon at d C 137.9 (C-8). Thus, the aforementioned evidence hinted at the presence of the diagnostic cembrane-type diterpenoid with one isopropyl, three methyl singlets, and one double bond in compound 1.…”

“…In particular, cembranetype diterpenoids bearing a 14-membered oxygenated macrocycle have received more and more interest in the laboratory studies of structural modication and natural product research, however, which are mainly contained in so corals. [11][12][13][14][15] Due to the difficulty of obtaining these so corals, there has been an increasing research into the cembrane-type diterpenoids obtained from terrestrial plants. Nowadays, more and more pharmacological studies have been carried out to research the chemical diversity of cembrane-type diterpenoids reported from the gum resin of Boswellia carterii, the acquisition of which is in great demand from the viewpoints of structural and pharmacological properties.…”

Quantification of Incensole in Three Boswellia Species by NIR Spectroscopy Coupled with PLSR and Cross‐Validation by HPLC

“…The Olibanum (Frankincense), collected by incision from Boswellia species (Burseraceae), has been used as incense since ancient times (Yoshikawa et al ., ; Wahab et al ., ). It is native to the Arabian Peninsula, India, and to northeast Africa (Badria et al ., ) and used as remedies in Sudan ( B. papyrifera (BP)), Oman ( B. sacra (BS)), and India ( B. serrata (BSE)), for the treatment of cold, cough, sore throat, and fever (Ogbazghi et al ., ; Thulin and Warfa, ; Paul et al ., ; Miller and Morris, ; Al‐Ghassany, ) and also for several medical conditions such as arthritis, anti‐inflammation, Crohn's disease, asthma, ulcers, and skin diseases (Hasegawa et al ., ; Atta‐ur‐Rahman et al ., ; Rehman et al ., ). The gum resin is used to make incense and as ingredients in perfumery, aromatherapy, fragrance applications in addition to food supplements and insect repellent (Wahab et al ., ; Al‐Ghassany, ; Miller and Morris, ).…”

Amino acids as chiral derivatizing agents for antiproliferative substituted N‐benzyl isoindolinones

“…Separation and identification of isomers are considered as two separate tasks and are solved independently of each other. Now, the establishment of the absolute configuration of optically active compounds is even more complicated than the separation, and it involves one of the following methods: X‐ray crystallography is optimal for identifying the structure of the chiral center of the molecule; however, growing the crystals that meet the requirements of the method is a laborious task; chiroptical methods analyze the interaction of polarized light with the compound and require special dichrometers, which are not common for most chemical laboratories; methods based on the analysis of NMR spectra obtained using chiral shift reagents or chiral derivatizing agents (CDA) are most widely used for the identification of optical isomers and determination of their ratio …”

“…• X-ray crystallography is optimal for identifying the structure of the chiral center of the molecule; however, growing the crystals that meet the requirements of the method is a laborious task; 4,5 • chiroptical methods analyze the interaction of polarized light with the compound and require special dichrometers, which are not common for most chemical laboratories; [6][7][8] • methods based on the analysis of NMR spectra obtained using chiral shift reagents or chiral derivatizing agents (CDA) are most widely used for the identification of optical isomers and determination of their ratio. 9,10 Mosher's acids and their analogs are the most known CDAs (Figure 2).…”