Minor Nortriterpenoids from the Twigs and Leaves of Rhododendron latoucheae

Abstract

A hyphenated NMR technique (analytical HPLC with a DAD connected to MS, SPE, and NMR) has proven effective for the full structural analysis and identification of minor natural products in complex mixtures. Application of this hyphenated technique to the CHCl-soluble fraction of Rhododendron latoucheae led to the identification of 15 new minor ursane-type 28-nortriterpenoids (1-15). Compounds 1 and 12 inhibited HSV-1 with IC values of 6.4 and 0.4 μM, respectively.

An Unexpected Oxidosqualene Cyclase Active Site Architecture in the Iris tectorum Multifunctional α-Amyrin Synthase

“…In contrast, ItOSC2 afforded α-amyrin (87% of total triterpenoids), together with β-amyrin and δ-amyrin as the minor products (Figure , SI Figures S6, S15–18, and S21–32, Table S5–6). α-Amyrin is the precursor of the ursane pentacyclic triterpenes that display potent anticancer, antiviral, anti-inflammatory, antidiabetic, and antiobesity activities. − Unlike β-amyrin synthases, OSCs producing α-amyrin predominantly (>80%) are rare in nature (Figure ).…”

Aquilariperoxide A, a Sesquiterpene Dimer from Agarwood of Aquilaria sinensis with Dual Antitumor and Antimalarial Effects

“…Compound 1, as a sesquiterpene dimer linked by a 7-membered peroxide ring, has attracted our attention due to its unique structural characteristics. To get a deep insight into the biogenesis of 1, a biosynthetic pathway of 1 was proposed based on 12,15dioxo-α-selinen 7 Natural products bearing a peroxide nucleus have been isolated from Artemisia annua, 8 Rhododendron latoucheae, 9 Emericella nidulans, 10 and Salvia officinalis. 11 They have been proven to have antimalaria, 8 HSV-1 inhibition, 9 and NO inhibitory activities.…”

“…To get a deep insight into the biogenesis of 1, a biosynthetic pathway of 1 was proposed based on 12,15dioxo-α-selinen 7 Natural products bearing a peroxide nucleus have been isolated from Artemisia annua, 8 Rhododendron latoucheae, 9 Emericella nidulans, 10 and Salvia officinalis. 11 They have been proven to have antimalaria, 8 HSV-1 inhibition, 9 and NO inhibitory activities. 10,11 Artemisinin, a typical anti-malaria natural agent with the peroxide bridge, has been found to have a broad range of biological properties such as neural protection, antitumor activity, and antiviruses.…”

“…Natural products bearing a peroxide nucleus have been isolated from Artemisia annua, Rhododendron latoucheae, Emericella nidulans, and Salvia officinalis . They have been proven to have antimalaria, HSV-1 inhibition, and NO inhibitory activities. , Artemisinin, a typical anti-malaria natural agent with the peroxide bridge, has been found to have a broad range of biological properties such as neural protection, antitumor activity, and antiviruses. − Sesquiterpenoids are a type of compound with diverse structures. Oxidation and cyclization are driving forces of structural diversity.…”

Insight into the Molecular Mechanism of Flower Color Regulation in Rhododendron latoucheae Franch: A Multi-Omics Approach

“…White mallow azaleas contain small amounts of delphinidin and cyanidin, whereas the petals of pink mallow azaleas have six times more cyanidin-3-O-rutinoside than those of purple mallow azaleas [ 13 ]. Most studies on Rhododendron plants have focused on the extraction of volatile components and triterpenoids from ocimene [ 14 ], genetic diversity [ 15 ], and translocation breeding and adversity stress [ 16 ]. However, none of these studies has investigated the metabolite composition in petals or explored the content of metabolites at different developmental stages, nor have they elucidated the mechanisms of gene regulation associated with flower color.…”