Floral Aromatics of Ptelea: Chemical Identification and Human Response

Many members of the citrus family (Rutaceae) are valued for the aromatic compounds emitted by their flowers. Ptelea species are unusually cold-hardy members of the Rutaceae, but conflicting descriptions of the fragrance of their unisexual flowers may discourage the use of these trees. We analyzed floral volatiles and human response to these chemicals to test the hypothesis that the fragrance of staminate and pistillate flowers of these species differs. Gas chromatography and mass spectrometry showed that most volatile chemicals emitted by flowers of Ptelea trifoliata and Ptelea crenulata are monoterpenes, sesquiterpenes, and esters. Most volatiles were emitted from flowers of both sexes, but ethyl benzoate and estragole were emitted only from pistillate flowers. When concentrations of aromatics differed between sexes, they were higher for pistillate flowers, except for cis-3-hexenyl butanoate and an unidentified terpene. For P. crenulata and P. trifoliata, respectively, 81% and 77% of survey responses were from volunteers who liked the fragrance. Panelists most frequently described the scent of flowers of P. crenulata of both sexes with the words citrus, lime, and sweet. Panelists distinguished between pistillate and staminate flowers of P. trifoliata, describing the odor of pistillate flowers most frequently with the words damp-earthy, spicy, and sweet; staminate flowers were perceived as light, fresh, grassy, and pleasant. This work represents the first analysis of floral volatiles of P. crenulata and resolves conflicting prior reports regarding the floral fragrance of P. trifoliata. We conclude that differences among people rather than the sex of flowers account for conflicting prior reports of floral fragrance. The scents of flowers of P. crenulata and P. trifoliata appeal to most people and are horticultural assets of these trees.

HS–SPME–GC–MS and Electronic Nose Reveal Differences in the Volatile Profiles of Hedychium Flowers

Floral fragrance is one of the most important characteristics of ornamental plants and plays a pivotal role in plant lifespan such as pollinator attraction, pest repelling, and protection against abiotic and biotic stresses. However, the precise determination of floral fragrance is limited. In the present study, the floral volatile compounds of six Hedychium accessions exhibiting from faint to highly fragrant were comparatively analyzed via gas chromatography–mass spectrometry (GC–MS) and Electronic nose (E-nose). A total of 42 volatile compounds were identified through GC–MS analysis, including monoterpenoids (18 compounds), sesquiterpenoids (12), benzenoids/phenylpropanoids (8), fatty acid derivatives (2), and others (2). In Hedychium coronarium ‘ZS’, H. forrestii ‘Gaoling’, H. ‘Jin’, H. ‘Caixia’, and H. ‘Zhaoxia’, monoterpenoids were abundant, while sesquiterpenoids were found in large quantities in H. coccineum ‘KMH’. Hierarchical clustering analysis (HCA) divided the 42 volatile compounds into four different groups (I, II, III, IV), and Spearman correlation analysis showed these compounds to have different degrees of correlation. The E-nose was able to group the different accessions in the principal component analysis (PCA) corresponding to scent intensity. Furthermore, the pattern-recognition findings confirmed that the E-nose data validated the GC–MS results. The partial least squares (PLS) analysis between floral volatile compounds and sensors suggested that specific sensors were highly sensitive to terpenoids. In short, the E-nose is proficient in discriminating Hedychium accessions of different volatile profiles in both quantitative and qualitative aspects, offering an accurate and rapid reference technique for future applications.

Analysis of Floral Fragrance Compounds of Chimonanthus praecox with Different Floral Colors in Yunnan, China

In order to better understand the floral fragrance compounds of Chimonanthus praecox belonging to genus Chimonanthus of Chimonanaceae in Yunnan, headspace solid-phase microextraction combined with gas chromatography-mass spectrometry was used to analyze these compounds from four C. praecox plants with different floral colors. Thirty-one types of floral fragrance compounds were identified, among which terpenes, alcohols, esters, phenols, and heterocyclic compounds were the main compounds. Interestingly, the floral fragrance compounds identified in the flowers of C. praecox var. concolor included benzyl acetate, α-ocimene, eugenol, indole, and benzyl alcohol. By contrast, the floral fragrance compounds β-ocimene, α-ocimene, and trans-β-ocimene were detected in C. praecox var. patens. Cluster analysis showed that C. praecox var. concolor H1, H2, and C. praecox var. patens H4 were clustered in one group, but C. praecox var. patens H3 was individually clustered in the other group. Additionally, principal component analysis showed that α-ocimene, benzyl alcohol, benzyl acetate, cinnamyl acetate, eugenol, and indole were the main floral fragrance compounds that could distinguish the four C. praecox with different floral colors in Yunnan. This study provides a theoretical basis for further elucidating the mechanism and pathway of the floral fragrance release of C. praecox.

Development from Jasminum sambac Flower Extracts of Products with Floral Fragrance and Multiple Physiological Activities

To obtain a potential commercial product with floral fragrance and physiological properties from Jasminum sambac flower extracts, enfleurage was conducted for a short time and followed by further extraction through supercritical fluid extraction (SFE). The product extracted through SFE (called 100%SFE) exhibited low physiological activity (including 50.7% antityrosinase activity, 38.6%–45.9% radical scavenging activity, and 6,518–15,003 mg/L half-maximal inhibitory concentration [IC50] of antioxidant activity) and an intense jasmine-like flavor but was nontoxic to CCD-996SK and HEMn cells. By contrast, the residue (called RO) exhibited high physiological activity (94.2%–100%), light jasmine-like flavor, and slight cytotoxicity at the concentration of 4,000 mg/L. When 100%SFE and RO were mixed in the ratio 2 : 8, the resultant mixture exhibited 100% antityrosinase activity, >91.3% radical scavenging activity, strong antioxidant activity (IC50: 273–421 mg/L), high total phenolic content (172.15 mg-GAE/g-extract), noncytotoxicity, and moderately intense jasmine-like flavor; it is also economically competitive. The major antioxidants in these extracts were revealed through gas chromatography-mass spectroscopy (GC-MS). Additionally, the composition and quality of fragrance were confirmed through GC-MS and sensory evaluation, respectively. The major fragrance components in the 2 : 8 extract mixture were benzyl acetate, β-pinene, pentadecyl-2-propyl ester, citronellol, jasminolactone, linalool, farnesol, and jasmone. On the basis of the results, we strongly suggest that the 2 : 8 mixture of extracts from J. sambac flowers can be a powerful antioxidant, whitening, and nontoxic ingredient that can be employed in the pharmaceutical, cosmeceutical, and food industries.

Michel Psellos’ Letter no. 33: Philosophical Explanation for the Odor of Sanctity

This article proposes a commentary and a Russian translation of Letter KD 33, written by the Byzantine philosopher Michael Psellos to his friend John Mauropous. Both correspondents were among the most prominent figures of the revival of Platonism in the 11th century. Their writings provide a notable example of the adaptation of Platonic philosophy to Byzantine needs. The letter was sent after a sorrowful event — the death of Mauropous’ brother, whose corpse, however, started to exude a sweet floral fragrance. Psellos argues that the “odor of sanctity” proceeds from the soul, which has received a divine ‎myrrh, ‎emanating from God. But how could it be that this supernatural aroma proceeds even after the soul’s departure? The author suggests that the human body partakes not only of the earthly primary substances, but also of the ether, which is involved in forming the man’s logos. During the process of dissolution between soul and body, the intellectual fire burns the earthly substances of blood out, whereas its heavenly substance continues to remain. This ethereal essence, retaining the sweet-smelling aroma of the soul, exhales it around after the physical death.